The Magnification Factor is Dead [Archive] - Canon Digital Photography Forums

Derek Smith

16th of October 2003 (Thu), 18:50

Long Live the Magnification Factor.

By now, many readers of this forum, particularly those who followed the ding between CDS and others re the ideal portrait lens, will have started to realise that they have been 'had on' rather nicely by Canon.

The 10D is a small format camera (wonderful, but small), and to disguise this fact some truly brilliant shmoozo at Canon came up with the brainwave to say 'No, it's not small format - IT'S A 1.6 FOCAL LENGTH MAGNIFICATION FACTOR' - so we all trot around thinking that we have a 35mm camera with some funny magnification built in that shortens the focal length of all the lenses that we are using.

To press the con home, the view through the viewfinder is presented exactly the same size as the size through an EOS3 etc. - probably by the use of a small magnification in the viewfinder optics.

Some by now will be reaching for the keyboard, ready to throw flame and hellfire at me, but before you do, let me explain--

A 50mm lens is a 50mm lens - that is, it will bring an image to a sharp focus exactly 50mm behind its primary objective lens.

When you clip a 50mm lens onto the 10D body, it brings the image to a sharp (some say sharpish) focus on the CMOS sensor surface. THERE ARE NO OTHER LENSES IN THE LIGHT PATH TO THE SENSOR. So the characteristics of the image are the characteristics of a 50mm lens - perspective, foreshortening and DOF (leaving CoC out of the discussion for the moment).

The only difference is - if we want to pretend that our little 22.7mm image is really a 35mm image, then we have to pretend that our lenses are a factor of 1.6 longer because that is the length of lens we would have had to have used on a 35mm camera to get the same content in our shot.

For those still skeptical - consider this exercise:-

Take a shot with an EOS3 on 35mm slide using a 50mm lens. Now take a scalpel and cut out a piece of the film 22.7mm x 15.1mm from the centre of the slide - that's the bit that the 10D sensor would have captured.

Now scan that piece and blow it up to any size you wish. Then tell me - What focal length lens did I use to take the image in my little 22.7 x 15.1 piece of film?

Now those amongst us that can tell a steaming pile of brown stuff when we smell it, will immediately realise that it does not matter how small you cut up the 35mm trannie, each bit was still imaged using a 50mm lens and will reflect the attributes of that 50mm lens.

If you want to go and blow up the little 22.7mm piece to 35mm and pretend that the 10D is a real 35mm camera, remember that no matter how much you blow up or shrink down an image - you NEVER CHANGE THE PERSPECTIVE or any other of the characteristics of that 50mm lens.

Me? I love the 10D and think that it is a breakthrough in performance and value. I even take my hat off to the shmoozo at Canon that dreamt up the 1.6x con - it had me thinking the smell was roses for a whole 6 weeks. But please -- a 50mm lens is a 50mm lens, and the perspective aspects which it creates stay constant no matter how big or little a piece of its focused image you choose to utilise.

So - what do you say? Can we all drop the 1.6x pretence and just accept that we have a small format camera (in a 35mm good looking body), and go back to talking about lens length selection with some degree of professional sensibility based on real lens length criteria? Or will some of you continue to give the shmoozo at Canon even more to laugh about?

Hey, you can't afford a 500mm lens? How about I sell you a clever piece of software that takes an image shot with a 50mm lens, and magnifies up the middle bit to 35mm, I could call it a 10x lens magnification factor - I'm sure some people would buy it!!!!! - hey I did!!

Derek Smith

defordphoto

16th of October 2003 (Thu), 18:54

Yeah so what's the point?

CyberDyneSystems

16th of October 2003 (Thu), 19:08

:D Nice one Derek,. :insert "worship" smiley here:

To whit,. any "magnification" that you percieve only occurs on the media,. just as if you cropped and blew up the image from a 35mmm film negative. The lens and camera do not alter magnification in any way.

robertwgross

16th of October 2003 (Thu), 19:23

Derek, perhaps you were taken in by the terminology when you purchased your camera.

I wasn't when I purchased my D60 about a year ago. I found that different photography people tried to explain it different ways, and the easiest way that I could understand it initially was that it "acted somewhat like a 1.6 teleconverter" was on each lens. Whenever I hear words like "somewhat" I know somebody is fudging in there. But, that over-simplification was what worked for me initially. Once I understood more of the details, I accepted reality.

I do have a 500mm lens (or, at least I own one if the Sigma repair shop gets it done). Effectively, it is 800mm. There are limitations to that thinking, but it works for me.

---Bob Gross---

Belmondo

16th of October 2003 (Thu), 19:44

So, what term works for you?

.6X field-of-view transmogrification?

1.6X reciprocal telephoto non-equivalency?

'So What' factor?

Maybe the best use of this board is for us all to put our heads together and to try to think of a term or phrase that satifies the need to accurately describe the phenomenon created by the smaller sensor without creating an air of sensor envy among those to whom such things matter.

It can be very ego-deflating to have someone point out that his sensor is bigger than yours. I don't see a great deal of harm in saying that your cropped image is equal to the field of view of a lens with a 1.6X greater focal length than his. It's all baloney, but it could avoid a fistfight.

CyberDyneSystems

16th of October 2003 (Thu), 19:49

:(

Hello,. My name is CDS.....

...and I have small sensor.

:(

defordphoto

16th of October 2003 (Thu), 19:51

CyberDyneSystems wrote:
:(

Hello,. My name is CDS.....

...and I have small sensor.

:(

ROOFL!

Belmondo

16th of October 2003 (Thu), 19:55

CyberDyneSystems wrote:
:(

Hello,. My name is CDS.....

...and I have small sensor.

:(

That's a good start. Now you only have 11 steps to go. Let's give CDS and his little sensor a big hand.

CyberDyneSystems

16th of October 2003 (Thu), 19:56

CyberDyneSystems

16th of October 2003 (Thu), 19:58

belmondo wrote:

Let's give CDS and his little sensor a big hand.

Don't put your big hands any where near my small sensor!

kfong

16th of October 2003 (Thu), 19:58

Derek Smith wrote:
If you want to go and blow up the little 22.7mm piece to 35mm and pretend that the 10D is a real 35mm camera, remember that no matter how much you blow up or shrink down an image - you NEVER CHANGE THE PERSPECTIVE or any other of the characteristics of that 50mm lens.

Perspective depends only on OBJECT distance. If you take a picture of a street corner using a 24mm, 50mm, 500mm without moving your camera, you'll have the same perspective, only the magnification and hence the FOV is different.

IT'S A 1.6 FOCAL LENGTH MAGNIFICATION FACTOR'

Maybe Canon should advertise it as "0.6 crop factor" instead.

Ken

defordphoto

16th of October 2003 (Thu), 19:58

robertwgross wrote:
Derek, perhaps you were taken in by the terminology when you purchased your camera.

Probably a lot of people are. They just don't understand what it really means. But to perceive it as some big conspiracy by Canon is going a bit far.

Sure these cameras are really 21.875mm and not true 35's, but personally I don't care. I like shooting in the sweet-spot of all my lenses. What some consider a downside, others make that an upside.

One thing that is being proven every minute of every day is that these 1.6-factor cameras are producing some of the finest photographs on the planet.

That's what really matters.

Heck, maybe 10 years from now we will be shooting better than medium-format resolution on a much smaller sensor than what we're using now. By then sensor size may not be an issue.

CyberDyneSystems

16th of October 2003 (Thu), 20:02

RFMSports wrote:
....What some consider a downside, others make that an upside.....

...That's what really matters....

....By then sensor size may not be an issue....

Yeah well,.. Don't delude yourself,. this is just what they say to make me feel better....

defordphoto

16th of October 2003 (Thu), 20:03

CyberDyneSystems wrote:
RFMSports wrote:
....What some consider a downside, others make that an upside.....

...That's what really matters....

....By then sensor size may not be an issue....

Yeah well,.. Don't delude yourself,. this is just what they say to make me feel better....

I know a good therapist I could hook you up with to deal with that size issue. :)

CyberDyneSystems

16th of October 2003 (Thu), 20:05

Sorry folks,. I have just been laughing myself to near death here.. I hope no one is offended! :D :D :D

defordphoto

16th of October 2003 (Thu), 20:06

CyberDyneSystems wrote:
Sorry folks,. I have just been laughing myself to near death here.. I hope no one is offended! :D :D :D

This forum could use a good belly laugh. The ice was getting pretty thick...

Belmondo

16th of October 2003 (Thu), 20:09

CyberDyneSystems wrote:
Don't put your big hands any where near my small sensor!

Don't worry. Any fingerprints on your sensor will not be mine.

defordphoto

16th of October 2003 (Thu), 20:11

belmondo wrote:
CyberDyneSystems wrote:
Don't put your big hands any where near my small sensor!

Don't worry. Any fingerprints on your sensor will not be mine.

Break out the sensorswabs!

lightandlife

16th of October 2003 (Thu), 20:24

Derek is right. The magnification factor is just an advertising gimmick. 10D only gives a cropped image of a normal or full size sensor. But didn't we have a lot of fun talking about the magnification factor? I think there is some entertainment value in there somewhere.

Let us wait for the next generation 10D with a full size image sensor.

Belmondo

16th of October 2003 (Thu), 20:30

I am personally hoping for a much smaller sensor so I can get even more magnification.

2X, 3X, or maybe even 4X.

mtimperman

16th of October 2003 (Thu), 20:39

The image is still focused on a 6 megapixel sensor. Just happens to be smaller than a 35mm piece of film.

danphoto1

16th of October 2003 (Thu), 20:40

I just enjoy my 10D maybe the small format in a 35 mm body is the reason Small camra small price!

CyberDyneSystems

16th of October 2003 (Thu), 20:51

mtimperman wrote:
The image is still focused on a 6 megapixel sensor. Just happens to be smaller than a 35mm piece of film.

6 should be enough,. but any woman would take 8 if given the choice.....

mattchase

16th of October 2003 (Thu), 21:05

Great thread, very funny. And thanks for finally explaining it in a way that really does make sense. That was one thing I have always had a hard time doing when somebody asks about / mentions the "magnification factor".

And now there is Olympus, who have created a great camera (am I allowed to say that here?), yet not only are they still trying to use the crop factor to their advantage by saying their 300mm lens is smaller, lighter, and cheaper but gives the focal length comparable to a 35mm's 600mm lens (because of the sensor size), they are SCREAMING it.

PS. Is your therapist friend female? And single? I have lots of problems... ;)

fredlord

16th of October 2003 (Thu), 22:22

I'm still waiting for the 240 megapixel digital replacement for my old Sinar F 4x5 view camera. Now that would be a digital. Then I'd need a bunch of those new 1-terrabyte compact flash cards they're working on just to hold a few images. Then I'd better have one of those new 50ghz, eight-processor Macs or PCs to work on the 20 gigabyte images on my 90" LCD monitor. Now, I want these things and I want them now. I think Canon and all the other camera/techno barons are robbing you and me of our rightful due by withholding what I know they've already got in those techno vaults. You and I both know they have these things and they're dribbling them out just to milk every last penny from our motheaten pockets before they drop the prices into less than stratospheric territory. Now there's a conspiracy. Who cares about some paltry little 6-megapixel toy like the 10D? Shoot film if you're worried. How about that?

Rob Larsen

16th of October 2003 (Thu), 22:46

It's not the size of your sensor that matters, it's what you do with it.

I try to expose mine as frequently as possible.

CyberDyneSystems

16th of October 2003 (Thu), 23:25

Rob Larsen wrote:
It's not the size of your sensor that matters, it what you do with it.

I try to expose mine as frequently as possible.

Well Done Rob!!!!!!!!

I was beginning to think I was alone in this! :D

Belmondo

16th of October 2003 (Thu), 23:37

CyberDyneSystems wrote:
6 should be enough,. but any woman would take 8 if given the choice.....

Unfortunately, so would most of the men in this group.

1Ds owners have 11, but NO MAGNIFICATION! How do they survive?

CyberDyneSystems

17th of October 2003 (Fri), 00:22

Now I KNOW I'm not man enough to handle 11!!!!!!!!!!!!!!! ;)

mattchase

17th of October 2003 (Fri), 01:41

Ya better be careful, it's actually 11.4 mp!

That said, I second the comment of it's not the size that matters, but what you do with it. Unfortunately, I don't get to expose mine as much as I would like.

And I can admit it...it is small, and I'm not ashamed! Whew, my therapist would be proud.

I'm going now before I get myself into trouble...

openspace

17th of October 2003 (Fri), 02:18

You're right. It's not a magnification factor. It's a crop factor. A 50mm on a 10D has the same edge crop of an 80mm. But the magnification is still that of a 50mm. But does it really matter? As an artist, you adjust. It's a new perspective.

And yes, the "negative" size is smaller than 35mm. But that in no way means the 10D is small format, as if it is comparable to the amazingly crappy APS format.

At 6.3 megapixels it still produces tack sharp images. With a bit of USM or Intellisharpen, my digital photos rival anything I ever captured on (slide) film.

RichardtheSane

17th of October 2003 (Fri), 03:55

Do you think those 1Ds owners are compensating for something??? :D

Rob Larsen wrote:
It's not the size of your sensor that matters, it what you do with it.

I try to expose mine as frequently as possible.

Nice one Rob!

Seriously, I just had a look an the Canon US site and it is not Canon that advertise it as the 1.6 magnification factor, that would be resellers and reviewers.
to quote canon on the official literature
"The effective sensor size (22.7x15.1mm) has the same 3:2 ratio as film cameras, enabling an effective angle of view that is 1.6x the normal EF Lens focal lengh"
Clever wording eh? :D

iwatkins

17th of October 2003 (Fri), 04:09

So my 17-35 lens is just a 17-35 lens ? Boo, I want my money back :)

And there was me thinking I could buy a 400mm lens and get an extra 240mm for free.

That's it, I'm going back to my old APS camera. At least that does widescreen

;)

Cheers

Ian

Belmondo

17th of October 2003 (Fri), 07:23

Can't sleep. Worried about puny sensor. People are laughing at my sensor. Must sleep.

Very confused. Welded tripod mounting ring to 50mm f/1.4 for nothing.

If 400mm lens really is 400 and not 640, where did other 240 go?

Too ashamed to blow dust off sensor in public. People will point and hide their children's eyes.

Must sleep.

MarkH

17th of October 2003 (Fri), 07:28

belmondo wrote:
CyberDyneSystems wrote:
6 should be enough,. but any woman would take 8 if given the choice.....

Unfortunately, so would most of the men in this group.

1Ds owners have 11, but NO MAGNIFICATION! How do they survive?

If I had 11 I don't think that I would really need it magnified. How greedy are you?

MarkH

17th of October 2003 (Fri), 07:41

Lets think about it this way:

Take a 10D and compare it to 2 fictitious cameras:
A. 6MPix FFS camera
B. 16MPix FFS camera
C. 10D

Compared to camera A the 10D magnifies the image by 1.6, but in doing so it crops the image (crops and magnifies the centre part). This means that you get more zoom length but you sacrifice zoom width.

Compared to Camera B the 10D produces a crop of the image and loses out on the wide angle. You can achieve the same results from cropping in photoshop.

I will look at trading in my 10D to buy camera B when the price is right.

BTW
Those that say that the 1.6 magnification factor (effective magnification, it is actually a crop) only happens when you print are wrong, it happens when you look through the viewfinder and you have to move back or zoom out to frame the subject the way you would with the same lens on a 1Ds or 35mm.

1.6x effective focal length conversion due to crop factor, good or bad? Depends whether you like the gain in zoom or loathe the loss in wide.

defordphoto

17th of October 2003 (Fri), 09:20

The terminology is all wrong here. Nothing is being magnified. It is a crop factor. The sensor is smaller than what our lenses see and crops 1.6 of what a true 35mm frame sees. It ain't rocket science. It's not some huge conspiracy by Canon. It is what it is. If you don't like it, go buy something else or wait for the next, true generation of dSLR's.

Belmondo

17th of October 2003 (Fri), 09:52

It's a concession to the cost of making high resolution sensors---probably the most expensive single component in the camera. We all understand the difference between crop and magnification, so let's not beat up Canon for trying to present it in a better light. For that matter, we need to be charitable to 10D/Rebel owners who either can't or won't acknowledge the difference.

In the meantime, I see nothing wrong with believeing in Santa Claus, the Easter Bunny, the Tooth Fairy, and 1.6X magnification.

And when the full frame sensor finally does come along, just think---the 17-40mm zoom you bought really will give you 17mm wide angle instead of 27mm. Life will be wonderful, indeed.

Derek Smith

17th of October 2003 (Fri), 11:36

Now I see why so little can ever be achieved by a committee.

10% understand and offer constructive comment, 10% don't understand ( but it's not their fault, because it wasn't explained clearly) and the rest are waiting for the dinner bell to ring.

Ho Hum, what shall I photograph now?

Derek (AKA Dot Counter) Smith

CyberDyneSystems

17th of October 2003 (Fri), 12:52

markh wrote:

BTW
Those that say that the 1.6 magnification factor (effective magnification, it is actually a crop) only happens when you print are wrong, it happens when you look through the viewfinder and you have to move back or zoom out to frame the subject the way you would with the same lens on a 1Ds or 35mm.

What makes the crop that the smaller sensor (relative to a 35mm) creates into an image that is "effectively magnified" (again only in relation to a 35mm) is the chosen output source.

If you were to print your 10D images @ 5"X6.25" as opposed to 8"X10" then you would be printing the image in the exact .625 ratio that the image sensor is in relation to a 35mm negative,.. and thus there would be no "magification" factor at all. (really it is enlargement at the printing side)

Yes the viewfinder has been altered to comepensate for the .625 difference in sensor size so we can frame correctly,. but again nothing in the optics or the cameras electronics is "magnifying" anything.

It isn't untill we decide to print or view the images in formats that we are used to printing 35mm negatives on that any enlargement occurs.

And yes,. it is in fact enlargement, not magnification. The 1.6X is an enlargement of a .625 crop. (in relation to a 35mm)

We just print all our images to sizes that DO NOT correspond to the .625 size difference of the 10D sensor relative to 35mm. That is the some total of any "effective magification"

And the funniest part is there is no crop either,. it is all only because we keep comparing it to a 35mm.. (which is understandable as we are using 35mm system lenses) but the Medium and large format guys are laughing at us because they know that we are comparing apples and oranges! :D Take 35mm out of the picture all together and there is nothing to compare against,. no crop no enlargement nothing. It is only the realtionship between the two formats that we are comparing.

If 35mm camera were using Medium format lenses then the 35mm would be a crop of the mauch larger medium format negative. But no magnifivcation would occur by using the medium formats on a 35mm negative,. the only way enlargement (or "effective magnification" )would occur is when we decide to print these theoretical negatives to print sizes consistent with Medum Format prints....

And on and on and on... :D

rdenney

17th of October 2003 (Fri), 14:12

(responding to the original post)

Of course. But the problem is that people use lenses because they include a certain portion of the scene from a certain vantage point. People don't look at a scene and think, "I need a 50mm perspective, so I'll put a 50 on my 4x5 view camera and then cut off 95% of the film." No, they find the place that gives them the best view of the scene, and then choose the lenses that includes the right amount of it.

So, when I use a lens that is twice the normal focal length on a 35mm camera, it will provide the same field of view from the same vantage point as a lens twice the normal focal length on a camera of a different format. The two pictures will look identical in all respects, with the possible exception of depth of field.

If I stand in one place and don't move, then a 50 is a 50 is a 50, as you say. But I don't stand in one place. I use a lens of twice the normal focal length for portraits because it gives me a nice head-and-shoulder shot from a reasonable working distance. A 50 on a 10D would get the head-and-shoulders shot, but a 50 on a 4x5 camera at the same position would give me the head, shoulders, body, and most of the room. Thus, I'd move closer to get the head-and-shoulder framing, and then the perspective would change.

Perspective is controlled by camera position. Lenses are chosen to provide the best field of view for a given composition once the camera position has been chosen.

Rick "who thinks this is a lot easier for folks who work in many formats to understand" Denney

tarves57

17th of October 2003 (Fri), 15:31

And I can admit it...it is small, and I'm not ashamed! Whew, my therapist would be proud.
-->[/quote]

ilya

17th of October 2003 (Fri), 17:00

Derek Smith wrote:
To press the con home, the view through the viewfinder is presented exactly the same size as the size through an EOS3 etc. - probably by the use of a small magnification in the viewfinder optics.

I'll see your con and raise you a conspiracy theory!

What if Canon designed the 1.6 FOV crop to sell more lenses? Folks who have a set of lenses for the full frame now have to fill the wide end a bit better. I hear in Europe they're already marketing new lens(es) for the 10D...

More on topic, CDS, I vote you now have to change your handle to: "The intersection of the size of things that are obvious to me and the size of things that are appear smaller to others is embarrassingly large" :D

==================
I'm not paranoid, but I could swear someone is out to get me!

Belmondo

17th of October 2003 (Fri), 17:16

ilya wrote: I hear in Europe they're already marketing new lens(es) for the 10D...!

Grrrrrr. Those darned Europeans get everything first. I think the 1.6X magnification factor --- ooops, I mean .6X cropping factor --- is a conspiracy by the New World Order to destabilize relations between heretofore friendly nations.

First, sensor envy, then Europeans getting lenses first. It makes me want to take my tiny little sensor and hurt somebody.

AJSJones

17th of October 2003 (Fri), 17:26

rdenney wrote:
(responding to the original post)
Rick "who thinks this is a lot easier for folks who work in many formats to understand" Denney

Great post Rick"....."

Why don't we call it a "format factor"?
After all 35mm is not the origin of all pictures; however, it has dominated so people feel comfortable saying it's "standard", so we could call it 1. Then the 10D would be 0.6 ish, as would APS, P&S digicams would be 0.2 or less (most of them), 645 would be 1.7 ish and 4x5 film would be 3.7 ish (quick and dirty diagonal comparisons). Divide the lens's true (and unchanging) focal length by this factor to get roughly the FL of the 35 mm equivalent needed to get the same image.

Ansel Adams's reaction to 35mm format : Nice miniature format you have there.

Andy

AllenGC

17th of October 2003 (Fri), 19:58

Hello all,

from my limited experience with film, (although I did own several Canon SLRs until last year), I would like to add this.

It appears to me that most of us, including myself, are initially attracted to a camera for the amount of pixels it produces/uses. Then we consider the other features of the particular model we are looking at, and perhaps the last thing we consider is the cropping/magnification ability.

If we like most of the features of a particular camera we buy it. It is invariably only after we have owned and used it for a week or whatever that we discover for ourselves the strengths/weaknesses of that camera, and if we can live with them the camera stays.

All of the cameras on sale have their own quirks, good and bad ones, focusing seems to be an issue on most, even though each new model is announced with faster and more accurate auto focusing. All of the cameras advertised are as advertised as the best in their range, or most of them anyway. So what do we have?

We have incredibly good advertising from the manufacturers, so good in fact that even though we go on to the forums and seek advice, and read good and bad reports, we buy that camera anyway! Why?

Because the advertisment has already made us hungry for the camera. I think that all of us with 10d's knew that the images would be soft, but we took a chance and bought it. Whether or not you got a model that focused correctly seemed like pot luck, but then you could always send it off and have it calibrated at your expense, Canon wouldn't mind. Soooooooo kind of them don't you think?

Then there is the cropping/magnification issue. We all knew that from the beginning, but why did Canon produce a 6.3 10d with a cropping factor of .6 for £1,500 and a full frame sensor of 11.4 mps for £5,500.

Because they could, and moreso because the market allowed them to! They have not just produced a camera for the semi pro or whatever with the 10d, they have very cleverly updated the D60 in the 10d for the everyday amateur/pro, and the 1d has been upgraded with the 1ds in order to satisfy the professionals, but more so to maintain the snob value and price of one of their cameras at least.

I am sure with the all money they make, and spend on furthering technology they could have come up with a full frame 6.3 10d, but they wouldn't want to because who would have bought the 1ds for £5,500? Only those who are interested in size, lol.

And now they are bringing out a new type of lens as seen on the 300d I believe, and these will assumedly be designed specifically for digital cameras, so, more money from the public who will run out and buy these lenses, because they will receive THE most wonderful press and everyone will want them, although as seen with their cameras, you wont be able to get them, but you will be able to read about them everywhere, and just when Canon think we are all going mad, they will produce them and put them in the shops, just as with the 10d, which is still in short supply. Why?

Because once again they can. Why? Because like it or not they are controlling the market, they are not spending money on producing cameras which might sit on a shelf for a month, oh no, they want orders first, why should they take a chance?

As for the point of the original thread.

In my limited opinion, I would agree with you if I totally understood it all. However, we have to stop thinking 35mm, and think about size, I mean pixels. Seriously! How many do we really need? Some suggest 4mps, but we are told over and over we need at least 20mps to equal 35mm. What rubbish!

I have printed A4 images from my 10d, and they are incredible to me, and as I don't sell them, I am the one whose opinions counts to me.

Stop being led by the camera companies, go with your own instincts, if 6.3 mps isn't enough, then all the threads from people singing the praises of the 10d etc have been in vain.

Stop comparing digital with 35mm, stop comparing the cropping factor, ignore the blurb, just consider your own images, are they good enough etc? Consider the cropping/magnification as a bonus. That should get Canon to produce a full frame 8/9 mps camera pretty quickly, they have got to get us to spend our money over and over on their products. I still have my G3 (which I only got it in March although I wanted it months earlier, once again not on the shelves) and the images from that are incredible, it never fails me, it is just slow compared to my 10d. It will always be good enough to keep for those group photographs that I can be in, thanks to the remote control.

Out of interest, someone on here at the beginning of this year said that Canon were bringing out a G5 soon, and a 8/9mps full frame camera in Sept/Oct this year.

They were right about the G5, and there is something in the air, the price of the 1d has just dropped £1,100 here in the UK.

Regards,

Allen.

HoldenMan

17th of October 2003 (Fri), 23:15

what's your point Derek?

I don't think there's a single person on this board who didn't know how the 1.6x magnification works.........

sorry, but I don't think it's the massive revelation you thought it was

robertwgross

17th of October 2003 (Fri), 23:24

AJSJones wrote:
...
Ansel Adams's reaction to 35mm format : Nice miniature format you have there.
...
Andy

Is that an actual quote from Ansel?

How about:
"The negative is the score, the print is the performance."
--Ansel Adams--

Or:
"It depends on what your definition of 'is' is."
--Bill Gates--

---Bob Gross---

Derek Smith

18th of October 2003 (Sat), 08:49

To AllenGC

Hi Allen, I agree with much of your post, however, let me please state loud and clear -

I love the 10D, its a great camera and a true breakthrough for Canon. Having tried it, I was one of the first in the queue in the UK to pull Canons arm off to own one and I am totally satisfied with the purchase. I am not complaining and I do not want my money back.

The reason for my original post was that so many people were playing ever crazier head games over the misconception that the 10D changed the focal length of their lenses. From that misconception, a whole load of further misconceptions were starting to spawn - DoF and perspective (re portraiture thread) being the most predominant, so I felt that it might be useful to this boards community to try to explain that the 10D does absolutely nothing to your lens nor to the aspects of the image that the lens produces.

The 'photography' issues relating to lens function and choice for use remain exactly as they were when the body was an EOS3 etc., appart from the fact that the 10D crops what the lense produces (with the slight exception that the 10D is possibly less tolerant to lens weaknesses than the better EOS 35mm bodies were - but that's another thread altogether).

I don't happen to think that it is right that new people coming to this forum, or to photography through the 10D, should be misled in this way. Nor should this forums members become the brunt of a new standing joke -

"Did you hear the one about the Canon 10D owner and his/her magical lens factor?"

Unless of course we are telling the joke about ourselves.

The 10D is great but fickle and I believe that this forum should be about uncovering that fickle nature and sharing the Tips & Tricks of how to get the best out of it with one another. Best then if we don't go creating or perpetuating figments or misconceptions.

Derek

To HoldenMan -

Time for dinner matey.

Derek

defordphoto

18th of October 2003 (Sat), 09:31

I think what bugs people most (read: ME) is that people keep beating the same horse over and over and over and over again. And they seem to think that it's some bif conspiracy by Canon to steal our money.

It just amazes me how people go out and buy a product, be it a lens, a car or whatever, FAIL to do the proper research into it and then sit around and complain about it.

Then they're all hot to sue the company because they don't feel they were properly informed. It's just the inherent mindset of our society these days. Nobody wants to take responsibility for their own actions and plain, downright stupidity.

Sure there are extremes, but this isn't one of them. Sure people don't totally understand the 1.6 CROP factor (it is NOT a magification factor), but then some people don't need to understand the ins and outs and all the technical aspects of the why's, where's and what's into what makes their camera work.

Yes, there have been some buggy cameras released by Canon, but they were fixed fairly quickly. This is from the pressure of current marketing to stay ahead of the competition.

My wife works for a major computer manufacturer and sometimes a product is released with known bugs that they fix AFTER the release. It's common practice in both hardware and software.

It just seems that the forums as of late have been ultra-negative and non-constructive.

We're all here to help each other be better photographers and yes, learn the ins and outs of our equipment. Bashing Canon or each other gets us nowhere.

I have developed a few email relationships via this BBS and it has been a wonderful experience on both sides. Sharing hints and tips and photos. New and seasoned photographers, whether they be pro, amateur, or pro-am all have something to offer here.

It'd sure be nice if we could get back to that helpful, constructive atmosphere we were enjoying a couple of months ago and get away from this destructive attitude that is permeating the board now.

[/soapbox]

P.S. This was not directed to Derek

Belmondo

18th of October 2003 (Sat), 10:07

RFMSports wrote:

It'd sure be nice if we could get back to that helpful, constructive atmosphere we were enjoying a couple of months ago and get away from this destructive attitude that is permeating the board now.

I couldn't agree more. It's just that the conspiracy theorists get so much enjoyment from promoting their viewpoints that to deprive them of this venue in which to do it would be tantamount to cutting off their oxygen.

Probably the best thing is to ignore those posts (and posters) that you feel are counter-productive to the overall spirit of cooperation that this board is based upon. If you don't react, they'll eventually lose interest and go elsewhere.

I'm relatively new to this group (since July), and I'm sure have had more to say than my level of expertise warrants, but I'm just really happy to be in a forum where there is so much kindred spirit floating around. There are names that I've become familiar with whose opinions are almost gospel. There are others who, like myself, are learning, but like to jump in from time to time purely for the exchange.

If we're tired of reading messages about focusing issues and 1.6X magnification conspiricies, all we have to do is skip over them.

ilya

18th of October 2003 (Sat), 10:51

RFMSports wrote:

It just seems that the forums as of late have been ultra-negative and non-constructive.

Dunno. I think its not the subject matter, its the negativity of the reactions to the subject matter. One can discuss in a very intelligent manner the pros and cons of the 1.6 "crop", I've seen it happen on another forum. One can also discuss the AF problem in a very constructive manner, etc. Its the overreaction of some posters to whatever topic that gives the whole forum a negative feel.

CyberDyneSystems

18th of October 2003 (Sat), 12:42

ilya wrote:

More on topic, CDS, I vote you now have to change your handle to: "The intersection of the size of things that are obvious to me and the size of things that are appear smaller to others is embarrassingly large" :D

==================
I'm not paranoid, but I could swear someone is out to get me!

:D rofl!

Well,. to make sure that Webster's sage words still applied to as many topics as possible I haven't changed the wording,.. BUT!

:)

I did put in BOLD in the hopes that fewer people would take any theory or advice I try to offer with any level of seriousness!!!!

:D lol

To be honest I for one have learned a great deal during these discussions and hope that I did not offend,. any time I post I try to do so with one of three intention or any combination of them.

1. To help others with Info I might have.
2. To gain knowledge form others who know better so that I may benifit from them.
3. With tongue firmly planted in cheek so that at least I may have a little fun,. but hopefully others do as well. :D

RichardtheSane

19th of October 2003 (Sun), 17:45

allengc wrote:
but we are told over and over we need at least 20mps to equal 35mm. What rubbish!

I must disagree with you there.
But before I continue I would like to hear your views on this, what do you believe equals 35mm film and what evidence do you have to support this?

I an always interested in the digital v film debate, quality wise and I will look upon any evidence with an open mind :)

MarkH

19th of October 2003 (Sun), 18:07

ilya wrote:
What if Canon designed the 1.6 FOV crop to sell more lenses? Folks who have a set of lenses for the full frame now have to fill the wide end a bit better.

Well, if that's their aim then they have messed it up. For most people with a decent range of lenses, they might consider buying a wider lens. But the wider lenses aren't so expensive. If you can get the equivalent of 640mm from a 400mm lens then you save a lot of money, more then enough to buy a 10D plus a wider lens and still have enough left to buy a reasonable used car.

ilya

19th of October 2003 (Sun), 18:13

markh wrote:
ilya wrote:
What if Canon designed the 1.6 FOV crop to sell more lenses? Folks who have a set of lenses for the full frame now have to fill the wide end a bit better.

Well, if that's their aim then they have messed it up. For most people with a decent range of lenses, they might consider buying a wider lens. But the wider lenses aren't so expensive. If you can get the equivalent of 640mm from a 400mm lens then you save a lot of money, more then enough to buy a 10D plus a wider lens and still have enough left to buy a reasonable used car.

That was tongue in cheek, as was the entire post.... "raise you a conspiracy theory"

However, I do wonder if cost is the only driver of the decision to go cropped. Why 1.6 for 10D, 1.3 on 1D, and full frame on 1Ds?

Edited

On second thought, let me ask a question. Has anyone foregone a long lens because they got a 10D? Just curious whether there are folks out there who would spend a "used car" on a lens actually changed their buying patterns. My guess is virtually none.

HoldenMan

19th of October 2003 (Sun), 20:43

Derek Smith wrote:

Derek

To HoldenMan -

Time for dinner matey.

Derek

uhh...yeah.........riiiiiiiiiiiiiiiiight.......... ......anyway *ahem*

which board is the portraiture thread on that you mentioned? I'll check it out later when I have time, see what these misconceptions are that you're talking about..........

HoldenMan

19th of October 2003 (Sun), 20:44

MarkH

19th of October 2003 (Sun), 20:49

ilya wrote:
However, I do wonder if cost is the only driver of the decision to go cropped. Why 1.6 for 10D, 1.3 on 1D, and full frame on 1Ds?

Well they are different prices, the larger the sensor, the dearer the camera

On second thought, let me ask a question. Has anyone foregone a long lens because they got a 10D? Just curious whether there are folks out there who would spend a "used car" on a lens actually changed their buying patterns. My guess is virtually none.

Well, I want a lens that is 600mm, but I wouldn't buy a 600mm lens due to the price being so high.

But I will replace my 10D in a few years with the new model with full frame sensor that is 16MPix or more. Then I can crop when I want to have the 1.6x multiplier.

If next year there were 2 cameras released to replace the 10D, one with 6MPix full frame and the other with 6MPix the same size as the 10D, which one would you buy? All other features being identical. I imagine the keen bird photograpers might prefer the 10D sized sensor while the landscape photographers would prefer the full frame sensor.

ilya

19th of October 2003 (Sun), 21:13

Your argument makes sense if the hypothesis was that one's camera buying decisions are driven by one's lens collection (which in itself is mostly true). However, my point was that your lens buying behavior is not curtailed by the fact that your FOV is cropped. If that were true, I suspect Canon would consider going less then full frame to be a bad business decision regardless of the cost differential in producing a 1.6 or a 1.3. All in all, I suspect that it doesn't really matter, one way or the other. Definitely IMHO.

rdenney

19th of October 2003 (Sun), 21:18

RichardtheSane wrote:
allengc wrote:
but we are told over and over we need at least 20mps to equal 35mm. What rubbish!

I must disagree with you there.
But before I continue I would like to hear your views on this, what do you believe equals 35mm film and what evidence do you have to support this?

I an always interested in the digital v film debate, quality wise and I will look upon any evidence with an open mind :)

It depends on our objectives. If our objectives are to make prints at the maximum size usually allowed by 35mm, then clearly the 1Ds has met or exceeded that standard, and the 10D comes mightly close.

But if our objective is to provide exactly the same image information as film, then we are nowhere close. This applies more to scanners than digital cameras, but it applies there, too. Digital cameras are different than film cameras, with their own strengths and weaknesses. To say one is better than or not as good as the other imposes a subjective qualitative assessment that defies analysis. We can say how they compare in terms of resolution, or in terms of color accuracy, or in terms of contrast, or what have you.

For example, if I wanted to reproduce a 35mm slide or negative using a scanner, I would want to be able to scan the very edges of the grain structures, so that at any scale, the two would be indistinguishable. This will obviously require vastly more pixels than we now have, and if I want an enlargement so large that those grain structures are obvious, then that's what I'll need. But I can produce a digital image just as large, though the micro-artifacts will look different.

One of the previous posters (Allen?) was correct when he said the only thing that matters is the number of pixels (and their sensitivity and color performance, of course). The format does not really matter. If the pixels are in a smaller format, then we need better lenses of different focal lengths. At some point with shrinking formats, our lenses will be diffraction-limited, but even the most expensive photography lenses do not attain that standard--they are too complex.

The Big Lie (if there is one) from Canon is that we can reuse our existing lenses. I do not regularly use any of the lenses that I used before I bought the 10D--they aren't good enough. Given that I ended up buying many new lenses anyway, I could tailor their focal lengths to the smaller format. (Note to CDS--I'm being a bit satirical here, which is a form of humor--oops, I almost wrote "heh, heh" but I've been warned about that before).

One of the things I like about larger formats is that they produce stunning results with lenses I can (approximately) afford. I bought 10 outstanding lenses for my funky Soviet medium-format cameras for the cost of two L lenses.

Rick "for whom 6MP is enough for the size prints he would use a small-format camera for in any case" Denney

AllenGC

19th of October 2003 (Sun), 21:34

Hello Richard,

I have absolutely no idea how many pixels one needs to equal 35mm film. I have however read in several places that until we get up to at least 20mps we will not obtain the quality of 35mm. I can't see the personal need for that many considering that I take photographs for the pleasure of it, more importantly, my pleasure, and the 10d seems to have more than enough for my personal needs. I don't care what other people think of them, I of course get added pleasure when someone enjoys my efforts. I am my own critic, I delete the bad ones, and admire the good ones. Am I happy with the good ones, yes! More than!

You ask for my views. As I asked before, why on earth are we comparing the two? In my humble opinion and limited experience I cannot see why we compare the film and digital in such depth. The comparison seems to spark off 'go nowhere' discussions. The film slr's use film to produce the images, and the digital uses a computer etc to do so. (That remark is not up for discussion). It is rather akin to discussing the old twin tub washing machines to the newer automatic models. You put your dirty washing in (never in public of course), and it comes out clean. The automatic machine is so easy, as is the digital camera. But you can't compare the two washing machines! Or I suppose there might be some that would, lol.

I have taken and printed some amazing images from my G3 (4mps) and 10d (6 mps), far better than I had ever had from my slr's in the past. Perhaps it is because I am taking more photographs now, and have improved or whatever, but I don't personally need more pixels.

I have never printed or had printed a 20x30, so wouldn't appreciate whether or not the 10d could produce an image big enough to blow up to that size. I have of late printed quite a few A4 edge to edge photographs, and have been delighted with them, I may want to go bigger one day but then I would have to get someone to print them for me.

I did read on one of the forums that technology is still at 4mps, or words to that effect, and that is all that we need to print decent photographs. Who am I to judge?

We are cajoled by intensive marketing into believing that more pixels will give us better photographs. A company has to continually produce new products in order to keep afloat and keep the shareholders happy. If they didn't they would go to the wall, and it would be of no use to them knowing that they produced the ZZZ model DLSR and sold 2 million of them in 2003, they wouldn't stay afloat on their laurels, so they employ engineers to continually design new products, and the most expensive advertising companies possible to make sure we, the public, will want their new product. Simple, it is called business, good business.

As Derek the original poster quite correctly stated, we are given information that is misleading to attract us to a product. How does anyone get away with that in this day and age? Of course Derek knew of the .6 cropping before he bought his 10d, he is asking why it is worded that way I believe.

For those who use the word conspiracy at the click of a shutter, or the computerised sound of one, the word you are looking for is 'opinion' not conspiracy, and everyone is entitled to one, even you, lol.

Regards,

AllenGC

rdenney

20th of October 2003 (Mon), 17:15

allengc wrote:
I have absolutely no idea how many pixels one needs to equal 35mm film. I have however read in several places that until we get up to at least 20mps we will not obtain the quality of 35mm.

A buddy of mine is a computer science professor specializing in graphical representations at the University of Alabama. He was the one who first made clear to me the distinction between duplicating a negative or slide and using a digital image directly for photography. So many seem to want to duplicate what film does down to the grain structure, while for image-making purposes the current structure of our image is more than accurate at current resolution to make prints as large as what we used to get from film with good quality. He reckoned that for photographic purposes (i.e., making as usefully large a print), 2400x3600 pixels would be plenty. He just bought an Olympus E1.

(Personally, I would like more dynamic range. I wouldn't mind a sensor with a range sufficient to require only one exposure to get all there is in the scene, no matter what settings we use. We could then adjust the tonalities as we wish after the exposure, and use the most effect aperture for lens performance and focus management. And, of course, a 100-MP sensor would make lens focal length much less of an issue. I'm willing to wait.)

I can't see the personal need for that many considering that I take photographs for the pleasure of it, more importantly, my pleasure, and the 10d seems to have more than enough for my personal needs.

Of course. That was my point in suggesting that the relative merits of sensors and film depend on your objectives. Your objectives are purely photographic, and for all practical (i.e. general photographic) purposes the 1Ds is already beyond 35mm film's capabilities.

You ask for my views. As I asked before, why on earth are we comparing the two? In my humble opinion and limited experience I cannot see why we compare the film and digital in such depth. The comparison seems to spark off 'go nowhere' discussions.

Yes, absolutely. For me, after about 30 seonds of post-processing, I can get an image that is as photographically useful (thought different) as a chemical print. In half an hour, I can get everything I would get from the chemical print even if I made it myself. But then I can really go to work on it, revealing tonalities that would not be possible when restricted by the tone curve on film and print materials. Whether I do anything artistic with that freedom and power is (fortunately) not the point.

I don't mind being told that my current equipment is obsolete, because I'm smart enough to know better, at least most of the time. I've been well-served by buying at least the third generation of any new camera technology, starting with the F-1 in 1972. My first full auto camera was a T-90, and my first autofocus camera was an Elan II. All represented complete maturity of their respective technologies.

But it is true that each breakthrough pulls in a new population of users who are not only new to digital photography (or whatever) but new to SLR's and the sorts of photographic techniques for which they are best suited. A digital camera is a powerful learning tool, however, providing instant feedback. I don't suspect that people are unwilling victims of planned obsolesence for very long.

As Derek the original poster quite correctly stated, we are given information that is misleading to attract us to a product. How does anyone get away with that in this day and age? Of course Derek knew of the .6 cropping before he bought his 10d, he is asking why it is worded that way I believe.

Who knows why Canon chose their words as they did? I suspect they consider the small sensor a weakness, and are trying to turn the weakness into strength by clever wording. I love extreme wide-angles, and knew that I would not have a short enough lens for the small sensor to satisfy that desire. But I still have the Elan II, and I figure if I really need the coverage of that 14, I'll shoot it on film. I'm finding that I didn't use lenses that wide as much as I thought I did--I haven't put a roll through the Elan since getting the 10D.

At the end of the day, what matters is how many pixels you have from one edge of the frame to the other, not what sensor/lens combination was required to produce it.

Rick "thinking we agree" Denney

Dave I

20th of October 2003 (Mon), 17:36

I don't get why you consider the 1.6x to be misleading.

If I want to get the identical framing/perspective as I would get with a 640mm lens on a 35mm camera at a given distance-from-subject, I put a 400mm lens on a 10D.

That sounds to me like I multiply the focal length printed on the barrel of the lens by 1.6 to figure out which lens I should use.

It's just a convenience for the end user, due to the fact that all the lenses were made for 35mm cameras, and most users are familiar with the 35mm camera 'feel' of things.

DAMphyne

21st of October 2003 (Tue), 17:29

If I stand on my porch and shoot a picture with my 35mm film camera with a 50mm lens, then use my 10D with a 50mm lens, take them both to wallmart for processing, the photo from the 10D looks like I used an 80mm lens.
I kinda like that.
It's like using a magnifying glass, it makes me feel good about myself.

Canuck

21st of October 2003 (Tue), 23:21

Oh man!

Now dare we start w/ the (bigger) sensor envy?

Where is this going? One person claims we're going to "L"

ROTFLMFAO!

Phil Hall

22nd of October 2003 (Wed), 02:13

Check out this site for more info

http://www.lonestardigital.com/multipler.htm

phili1

19th of December 2004 (Sun), 07:32

I came her because Cyberdynesystems said you could get an answer here. What I have seen is Derek who has the same questions and answers I have come up with but instead there is allot of joking.

Anyway I am going to make a statement and would like an answer from someone who knows.

A 35 mm Camera, a so called normal lens is 50mm which gives a certain angle of view put on a 10D or 20D can not be called an 80mm lens because of the following. It does not bring the subject in any closer. What I see is that the only thing effected is the angle of view, and the magnification and perspective says the same. So stating that a normal lens on a 20D would be 31.125 would be wrong because you change the perspective by going down to 31.125mm.

Wow am I confused, 20 people talking about a subject all with different insight.

Well I have a solution I am going to think of my 20D as a 20D and not a 35mm and my 100-400Lmm lens as a 100-400l and shoot pictures with it and not worry about the statistics.

Do you know what the funny thing about this is, 20 years ago we had the same discussion concerning 35mm and 2 1/4x 2/14 and why the larger format was better and after 10 years the industry almost went 100% 35mm in wildlife, 25% shifted to wedding because of it's ability to adapted and 100% in sports. Now they are going Digital. :rolleyes: :rolleyes:

PacAce

19th of December 2004 (Sun), 08:00

I...
A 35 mm Camera, a so called normal lens is 50mm which gives a certain angle of view put on a 10D or 20D can not be called an 80mm lens because of the following. It does not bring the subject in any closer. What I see is that the only thing effected is the angle of view, and the magnification and perspective says the same. So stating that a normal lens on a 20D would be 31.125 would be wrong because you change the perspective by going down to 31.125mm.
...:

There was a discussion recently about this you might be interested in reading if you haven't already. See here:

http://www.photography-on-the.net/forum/showthread.php?t=50556

And another source:

http://www.reasonableexpectations.com/Photo_Myths/Perspective/perspective.htm

Persian-Rice

19th of December 2004 (Sun), 08:24

I think that some of these accusations are a product of ignorance.

To say that this board is taking a negative turn at times is correct, but posting this long thread based on opinion is not right. To make a mistake is one thing, to claim to know and actually not is something else. The whole point is to learn and teach, in some cases, so that the misinformed can learn and not make the mistake twice, not run away and avoid the issue.

I won't explain very much, but you should learn about the actual technical reasons for the "crop factor". It is not some conspiracy software in the camera. No one claims that the actual focal length of a lens changes. However, it creates a simulated focal magnification. Some of the claims here almost sound like Canon has a very good digital zoom on the EOS Digitals. A crop factor is an advantage and disadvantage. It is the cause of the lack of technology at a low price. Canon can create full sized sensor for all their Camera's, it always has, but then you wouldn't be able to afford a dSLR.

BTW Allen, there is no given amount of "pixels"(you should be calling them photosites)to create an equivalent to 35mm. It is all down to sensor dimensions and placement, but mostly on dimensions. Photosites are the individual light sensitive elements on the surface of the sensor. You can have big ones..........or small ones. This is the reason the 10D is a 6.3 and the 20D is a 8.2 and they are still using the same size sensor. BTW, The smaller the photosite the more the noise, for a whole different and somewhat complicated reason. In short, a small photosite absorbs less light and the processor boosts that value and returns an incorrect color. However, with the advancements in camera processor efficiency and photosite sensitivity, that issue appears to be on its way out.

Cheers

photog

19th of December 2004 (Sun), 09:07

There's one upside I think I see to the "cropping factor" in cameras with smaller sensors.

A lens designed for 35mm projects a 43mm diameter image circle from which a 35mm film camera uses a rectangle of 36X24mm.

Project that same 43mm image circle on to a smaller sensor and the image is cropped from of the center of the circle.

The upside I'm thinking of is that if there is any edge softness involved with the lens being used, some of it won't be picked up by the smaller sensor.

Since I use a 20D, for me this begs the questions:

Do the Canon EF-S lenses project a smaller image circle than a lens designed for 35mm?

If they do could this be the reason for some of the complaints of edge softness I've heard with the EF-S lenses compared to EF lenses?

Persian-Rice

19th of December 2004 (Sun), 09:31

photog, I am not sure but it could also be that the lens sits further out..........

Nic

19th of December 2004 (Sun), 09:38

Did Canon tell (instruct) Nikon that they must also use a 1.6 cropping factor???

gcogger

19th of December 2004 (Sun), 09:58

Steven M. Anthony

19th of December 2004 (Sun), 10:14

photog

19th of December 2004 (Sun), 10:22

Yes - EF-S lenses project a smaller circle. If you somehow made one fit a full-frame camera, you'd have nice black corners :)
OK, in that case, I have to ask that since the projected image circle is smaller, is there a "cropping factor" still involved with the EF-S lenses on a ".6x" sensor?

gcogger

19th of December 2004 (Sun), 10:28

OK, in that case, I have to ask that since the projected image circle is smaller, is there a "cropping factor" still involved with the EF-S lenses on a ".6x" sensor?

Yes, which is why 'crop factor' is perhaps not a very good term. An EF-S lens at 50mm on a 20D will still give the same field of view as an 80mm lens on a full-frame camera.

photog

19th of December 2004 (Sun), 10:39

Yes, which is why 'crop factor' is perhaps not a very good term. An EF-S lens at 50mm on a 20D will still give the same field of view as an 80mm lens on a full-frame camera.OK, let me see if I got this right...

The EF-S projects a smaller image circle but, due to the focal length of the lens, the image in that image circle is still "full sized" so the sensor sees the same image as with an EF lens of the same focal length.

Phew...my head hurts...:)

Thanks.

PacAce

19th of December 2004 (Sun), 11:42

OK, let me see if I got this right...

The EF-S projects a smaller image circle but, due to the focal length of the lens, the image in that image circle is still "full sized" so the sensor sees the same image as with an EF lens of the same focal length.

Phew...my head hurts...:)

Thanks.

Here's an analogy for you to make this very simple to understand. Look out a shuttered window which has both shutters opened. Note the size of the things outside the window (EF lens) such as that car parked across the street. Now, close one of the shutters so that you're only looking out of half the window (EF-S lens). Did the size of the car parked across the street get any smaller when you did that? Nope, not one bit although you are getting less of the view of the outside from the half-shuttered window. :)

CyberDyneSystems

19th of December 2004 (Sun), 12:34

I came her because Cyberdynesystems said you could get an answer here. What I have seen is Derek who has the same questions and answers I have come up with but instead there is allot of joking.

Phil,
Indeed.. I said you could get answers.. many answers... :)
One can never guarantee,.. nor would I ever assume to do so,. that the answers are ones that you will like. :)

It seems that with this particular subject.. it is very rare that any two people will like the same answer.

I referenced you to the many links to this subject in the hopes that one of the dozen or so links to previous discussions should shed some insight on your questions. If they have not,. I am sorry. :(

Some of these threads do hold a lot of valuable info.. Belmondo's thread where he took the time to create graphics to illustrate it are a good example. In fact the post with the links I made tries to explain in brief what value each thread has... this particular thread you chose to post in which dates back to 2003 is labeled simply "the longest thread on the X-factor" in my links.. thus in my mind implying that the subsequent discussion was not the inherent value of the thread. In this case, no question was asked by Derek. His post is a complete work. And a valuable one. I my mind his conclusions provide the bulk of the required info one would need to grasp this concept.

However there is a second possible understanding that can be gained by referencing those links, the understanding of a possible level of futility. By illustrating that despite the dozens of threads we have had here,... depsite the literally tens of thousands of words on the subject saturating photo sites all across the web,.. (many of which are linked to in these forum threads..) it seems that there is no way to answer this question for everybodies liking.

Thus.. if after now a few weeks of asking and you can not find an answer you like.. and I know many have tried to answer your question,.. perhaps you simply won't.

In essence Phil,. having bandied this about now for a few weeks with multiple threads,. the best answer that can be offered is this.

Perhaps there is no one here that can answer your question to your liking.

:)

CoolToolGuy

19th of December 2004 (Sun), 13:57

I try to compensate with the length of my lens.....

http://www.sigmaphoto.com/Images/news/500f4_5EX_lg.gif

.... but now I am at a loss because I thought it was 800mm when in fact it is really only 500mm :(

Is 500mm enough?

Why do Blonds park so close to the curb?
because men are allways telling them that there 500mm is really 800mm I have a special hood for your lens to accommodate the small sensor. But I'm afraid it might be **** out for our British members (hood, that is) due to inappropriate language and they won't see it ;) :D

Have Fun,

pcasciola

19th of December 2004 (Sun), 14:02

Perhaps there is no one here that can answer your question to your liking.
:)
Ding, ding, ding.... I think CDS hit the nail on the head. :-)

The only thing worse than yet ANOTHER X-factor thread is a one year old revived x-factor thread.

This will be argued for years to come. My contention is that unless the resolution of the smaller sensor is much lower, calling it cropping is just plain wrong. If you crop 1.6x out of the center of an 8MP full frame shot to match the area captured with an 8MP APS-C sized sensor, the APS-C sensor's shot WILL have more detail over that same area, period. This is a simple fact that cannot be argued.

Using the same lens from the same distance, and cropping them all to match would yield approximately the following image sizes:

2200x1500 - 8MP full frame cropped down to match the APS-C sized shot
2500x1700 - 11MP (1Ds) full frame cropped down to match an APS-C sized shot
3500x2300 - 8MP APS-C sized sensor shot

My math might be a little off there, but I was roughly basing it off the horizontal size of the sensors (36mm for the full frame vs 22.5mm for the APS-C sized sensor).

I think it's closer (although a little worse) than using a tele-extender, and even though that is "cropping" 1.4x out of the center of the frame and magnifying it, calling that cropping would be equally as wrong in my opinion.

Steven M. Anthony

19th of December 2004 (Sun), 14:20

CDS said "...it seems that there is no way to answer this question for everybodies [sic] liking."

That's because not everyone likes to know the truth. And I don't mean that as a wise-crack. There are simply those people who would rather believe they are right (and have a magically magnifying sensor) than find out how things really work. It happens in all aspects of life--not just regarding the X-factor--and explains why people believe in the teachings of some of the major organized religions of the world.

What I find interesting is that this particular topic is such a hot one. Religion, sure. Politics, I can see that too. But the X-Factor? Maybe it's the desire for magic...

RDKirk

19th of December 2004 (Sun), 17:45

Perspective depends only on OBJECT distance. If you take a picture of a street corner using a 24mm, 50mm, 500mm without moving your camera, you'll have the same perspective, only the magnification and hence the FOV is different.
Ken

Subject distance AND format (framing). If you put a 50mm lens on a 6x6cm camera at a given distance to a subject, it will show the exaggerated perspective of a wide angle. If you put a 50mm lens on a 24x36mm (full frame 35mm), it will show a "normal" perspective of the same subject at the same distance. But if you compare a 24x36mm crop of the center section of the 6x6 image, it will look identical to the 35mm image.

The perspective in the image depends on both distance AND format (framing).

RDKirk

19th of December 2004 (Sun), 18:01

The 10D is a small format camera (wonderful, but small), and to disguise this fact some truly brilliant shmoozo at Canon came up with the brainwave to say 'No, it's not small format - IT'S A 1.6 FOCAL LENGTH MAGNIFICATION FACTOR' - so we all trot around thinking that we have a 35mm camera with some funny magnification built in that shortens the focal length of all the lenses that we are using.

Hey, can two ride that hobby horse?

You're right, although I'd quibble about why someone at Canon or wherever came up with the concept. I figure it was someone in Marketing's idea to ease 35mm camera owners (who already had lenses) to buy DSLR bodies.

However, the dirty deed has been done, and it is a bad concept that muddles the minds of many newbies to the SLR world. It has people who have never owned 35mm cameras and who never will own a 35mm camera wandering around wondering "It says '50mm' but is that like 75mm or is it really like 50mm?"

Yes, it's a different format. It's not a crop factor of 35mm any more than 35mm is a crop factor of medium format; it's a different format. It's 20.5x15mm. The normal lens is 28mm. Everything short of that is wide angle, everything longer than that is telephoto (yes, I know "telephoto" actually refers to a specific kind of lens design).

Photographers who have long used two formats of cameras never stroked their chins and calculated crop factors. They just said, "The lens on my Canon is twice the normal focal length, so I'll put a lens on my Hasselblad that's twice its normal focal length."

To press the con home, the view through the viewfinder is presented exactly the same size as the size through an EOS3 etc. - probably by the use of a small magnification in the viewfinder optics.

Now, here is a real con, I agree. Canon's 20D specs say of the viewfinder magnification:
"0.9x (-1 dpt. with 50mm lens at infinity)." Oh, hey, that's close to the holy grail of 1x magnification--that's a good thing, isn't it?

But that's with a 50mm lens...which is nearly a 2x telephoto on an APS-C format camera. In reality, the magnification with a 28mm lens (the normal lens for the format) is more like .5x, which is 'way worse than SLRs have been for a long, long time.

They could boost the magnification, but that would dim the viewfinder. They could redesign the viewfinder to match the format, but that would cost money. As long as they keep consumers befuddled as to what the real normal focal length is (notice they don't release a prime lens with these cameras--just zooms) they can get away with the con.

Andy_T

19th of December 2004 (Sun), 18:28

Subject distance AND format (framing). If you put a 50mm lens on a 6x6cm camera at a given distance to a subject, it will show the exaggerated perspective of a wide angle. If you put a 50mm lens on a 24x36mm (full frame 35mm), it will show a "normal" perspective of the same subject at the same distance. But if you compare a 24x36mm crop of the center section of the 6x6 image, it will look identical to the 35mm image.

The perspective in the image depends on both distance AND format (framing).

This is not correct.

Framing only changes the perspective if you move closer to or farther from your subject to 'frame' it because of different FOV.

UNLESS YOU MOVE THE CAMERA, THE PERSPECTIVE WILL STAY THE SAME.
FOV changes with focal length and sensor size.
DOF changes with focal length and sensor size (because of magnification).

But the picture you take with a 20 mm lens and enlarge it x times so you have the same FOV as on the picture taken with a 100 mm lens, will have exactly the same perspective.

Best regards,
Andy

(OK, if you still don't believe me, look here for examples: http://www.mhohner.de/essays/myths.php#focalper ;-)

RDKirk

19th of December 2004 (Sun), 19:35

This is not correct.

Framing only changes the perspective if you move closer to or farther from your subject to 'frame' it because of different FOV.

UNLESS YOU MOVE THE CAMERA, THE PERSPECTIVE WILL STAY THE SAME.
FOV changes with focal length and sensor size.
DOF changes with focal length and sensor size (because of magnification).

But the picture you take with a 20 mm lens and enlarge it x times so you have the same FOV as on the picture taken with a 100 mm lens, will have exactly the same perspective.

Best regards,
Andy

(OK, if you still don't believe me, look here for examples: http://www.mhohner.de/essays/myths.php#focalper ;-)

Clearly, you didn't read my post very closely.

If you stand in one position and take a picture with a 50mm lens on a 35mm camera, you will not see wide-angle perspective. If you stand in the same spot and take a picture with a 50mm lens on a 6x7 camera, you will see exaggerated perspective.

What changed? The framing (i.e., the field of view). If you don't move or change focal length but increase the field of view, you will change the perspective captured by the camera.

CyberDyneSystems

19th of December 2004 (Sun), 19:43

RD,
What your describing is a change in the image, appearance, the field of view... etc.... but it is not "perspective". It simply is a matter of definition.. but what you are describing is not what "persective" means. Other than that,. . your right on the money.

flyfishnj

19th of December 2004 (Sun), 20:22

Holy $hit - You guys are still arguing this? It's like Groundhog Day ...

Pekka - Can I block individual threads? ;)

flyfishnj

19th of December 2004 (Sun), 20:27

BTW - Who is the masacist who revived this dead dog of a thread?

DocFrankenstein

19th of December 2004 (Sun), 21:05

BTW - Who is the masacist who revived this dead dog of a thread?
It even mentions that the topic is DEAD in the name of thread :D

pradeep1

19th of December 2004 (Sun), 21:52

Yeah, this new "Similar Threads" forum feature is giving every idiot a longer lasting soapbox. Can you imagine a few years from now threads like this keep popping up? Maybe the moderators should put a warning on reviving dead threads like this? Any thoughts on how to acomplish this?

:p

Steven M. Anthony

19th of December 2004 (Sun), 22:09

pradeep1 said: "Yeah, this new 'Similar Threads' forum feature is giving every idiot a longer lasting soapbox."

So are those who feel compelled to comment on the fact that old threads are being revived...

DocFrankenstein

19th of December 2004 (Sun), 22:12

Some [name of the guy] law states:

Amount of known information being regurgitated is infinitely larger than the amount of new appearing.

Just accept it

okbirdman

20th of December 2004 (Mon), 07:53

What might the next upgrade of the 20D bring? It they up the sensor size, they might lose sales to the 1D MarkII.... Of course there are numerous other differences between the two cameras (weather seals and autofocus improvements, plus many others), but the 20D currently is pretty darn close to the quality of images from the ID for a lot less $$.

flyfishnj

20th of December 2004 (Mon), 08:18

Flashback moment ----

"I just bought a D60 - What lens should I buy? ";)

Jon

20th of December 2004 (Mon), 13:01

slin100

20th of December 2004 (Mon), 13:04

This thread has gotten quite long. I'm replying to Derek Smith's original post because in attempting to highlight the misconception/misnomer of the term "1.6x magnification factor", Derek introduced a few other misconceptions.

To summarize Derek's position, he asserts that, "A 50mm lens is a 50mm lens." Therefore, perspective and DOF, which Derek asserts are charactersistics of the lens, are unaffected by the sensor size. To support the assertion, Derek posits the following experiment. Put the 50mm on a 35mm film body and cut out the central portion of the resulting image to conform to the image as would be captured on a 22.7mm x 15.1 mm format sensor. Lo and behold, the image is identical! QED

Unfortunately, this experiment doesn't validate all of the claims.

First, DOF is not an inherent property of a lens. It is a subjective interpretation of the captured image when viewed by a person. Despite this subjectivity, DOF can be quantified into a mathematical formula. The subjectivity is not lost in doing so. The mysterious Circle of Confusion (CoC), which describes a person's ability to discern those points of an image not in the plane of focus that have been rendered as circles by the lens, preserves it. You can't leave CoC out of the discussion; DOF and CoC go hand in hand.

Second, DOF is affected when the sensor format changes. But, wait, Derek's thought experiment says it's not. Derek's assertion is true but not particularly relevant because it's an apples and oranges comparison. The relevant comparison that people generally care about is the one that not only preserves the field of view and photographic perspective but does so using the full extent of the sensor. So, no cutting out the center of a film frame; use of all it! This implies using different lenses (an 80mm on a 35mm film body and a 50mm on a 10D/20D/300D, for example) on each camera! You must use different lenses in order to stand in the same spot and maintain perspective.

Once you accept that different lenses are needed, it shouldn't be too hard to realize that the DOF is likely to be affected. I'm not going to go into the math. If you want to see the math, go to http://www.photo.net/learn/optics/dofdigital/index.html for an, IMO, unassailable argument upon which I base my statements. I'll just repeat the result that the DOF of an image produced by the 10D/20D/300D and projected to the same size as an image captured by the 35mm film body will be at least 1.6x greater. BTW, it's no coincidence that the DOF difference is the same as the so-called "1.6x magnificaton/crop factor."

Third, photographic perspective is defined as the size relationship of objects within a scene to each other. This notion of perspective is different than what others use, which often incorporates field of view. In photography, perspective and field of view are treated separately. Given this definition of perspective, it can be stated that a lens does not affect it. Only the distance of the lens from the subject affects perspective. If you stand so that subject A in the foreground looks half as tall as subject B in the background, it doesn't matter what focal length lens you use. The relative size of each subject to the other will not change so long as the distance to the lens is unchanged.

In closing, there's is very little that is unaffected by changing the size of the sensor. FOV, DOF, and even the minimum handheld shutter speed (aka the 1/focal length rule) are affected. Only perspective remains unchanged. I hope this provides some clarification to a very muddied topic.

On an unrelated note, Derek also claims that the view through an EOS 3 viewfinder is the same as the 10D. That's certainly not the case. Even though the 10D viewfinder does have a different magnfication ratio, the image as projected on the viewfinder is much smaller in the 10D.

Jon

20th of December 2004 (Mon), 13:14

Did Canon tell (instruct) Nikon that they must also use a 1.6 cropping factor??? Yes, but Nikon being Nikon, they ignored that sage advice. Nikon's firmly committed (for public consumption, anyway) to a 1.5x cra^hop factor on all their digitals.

Mark Kemp

20th of December 2004 (Mon), 14:08

Personally I just look down the viewfinder and if I don't like the image I change the lens or move to a different location. All I need to know is that smaller numbers make the picture wider and bigger numbers make it narrower. I don't care what its equivalent to on a 35mm camera or an APS or 6*6 as I don't have one of those in my hand.

I care about what the picture looks like: so a dslr with this lens is different to a different sort of camera with a similar lens - so what - get over it - worry about whether you took a good picture or not

Steven M. Anthony

20th of December 2004 (Mon), 15:13

slin100

20th of December 2004 (Mon), 16:18

slin100 said: "The relevant comparison that people generally care about is the one that not only preserves the field of view and photographic perspective but does so using the full extent of the sensor."

I'm not sure where you pulled that generality out of... I consider that comparison an apples-to-oranges one. Considering it an apples-to-apples comparison leads to the magical belief that things like DOF, magnification and even the minimum handheld shutter speed guideline(aka the 1/focal length rule) are affected by the mere size of the sensor.

In reality, DOF, magnification and perspective are unchanged--just as one would expect if one cropped a contact print. The result is a smaller amount of the original image--but everything else is the same.
Steven,

We've had this discussion before in a different thread. Perhaps you can explain why you consider this an apples-to-oranges comparison. I certainly don't think it is and disagree very much that the resultant beliefs are magical.

To me, your notion of cropping a print is the apples-to-oranges comparison. My comparison equates the situation where you have two people, one with a film camera and one with a DSLR. Ask them to stand in the same spot and capture the same scene (meaning identical FOV, focus distance and aperture) using their equipment to their fullest. The person with the film camera is not going to capture more than the specified FOV and then crop it down to match the DSLR. So, why are you suggesting this? If you accept that the equipment used is going to be different, and this means that the lenses are different, then why can't you accept that the relevant characteristics of the image, like DOF, will be different?

I really wish you would read this article http://www.photo.net/learn/optics/dofdigital/index.html. I believe it makes all of my points much more convincingly than apparently I have been able to. It even addresses your notion of cropping a print and how it does indeed produce the same DOF, but that the comparison is an apples-to-oranges one. I guess I'll have to go ahead and cite a portion of the article by Bob Atkins:
The 1.6x "digital multiplier" for lenses corresponds directly to a 1.6x "DOF multiplier" when comparing the 10D to 35mm when you use lenses with the same angle of view.

I'm sure some people will say, OK, but what if you don't take angle of view into account. What's the relative DOF if you use the SAME lens on an EOS 10D and a 35mm film body?

Now you run into the problem of what you are comparing to what. The same lens on the two formats will give you different fields of view, so if you enlarge each image to the same size (say 8x12), you won't have the same print so you really can't compare DOFs. If you crop the 35mm negative to give you the same print as the digital image the answer is easy. The DOF in the cropped 35mm print and digital image print will be exactly the same. You're using the same lens and same size image (cropped 35mm or digital), so you get exactly the same DOF.

Steven, you're one of the people who doesn't take angle of view into account and insists on using the same lens. While you can certainly draw some conclusions from that exercise, to me they don't serve any useful purpose.

Steven M. Anthony

20th of December 2004 (Mon), 18:11

slin100,

Comparing the full sensor image between a full-35mm-frame sensor and a 10D-sized sensor is apples-to-oranges BECAUSE THE SENSOR SIZES ARE DIFFERENT. It's like comparing the performance of a Ford Fiesta and a McLaren F1 on the grounds they are both cars--ignoring the fact they their respective engines are of different sizes. Of course a McLaren will trounce a Fiesta--the McLaren has a 6 liter engine! You can go ahead and make the comparison--but it's not one that makes much sense.

The point here is that the size of the sensor does not change the optics of a lens (if the lens is NOT designed to "fit" the sensor). You do not have a situation where the equipment is different: the lenses are the same--the only thing that is different (with the exception of the software and the shape of the camera casing in some instances) is the size of the sensor.

The article you wanted me to read--which I have since read--makes they very point (in a part you did not copy above).

I suggest the "crop the larger image to match the smaller" method to highlight the fact that smaller sensors DO NOT magnify more than large sensors. Period. If you want to add in other factors--like moving the shooters around--fine. But it does not change the fact that smaller sensors DO NOT magnify more than large sensors.

If you wish to continue this discussion, please send me an email to santhony@mn.rr.com

Steven M. Anthony

20th of December 2004 (Mon), 18:26

let me add, after some thought, that the car analogy isn't quite on target. the issue here is that we have an optical system--with certain characteristics like dof, magification factor, etc.) designed for a 36X24mm sensor (i.e., 35 mm film) and have interoduced a smaller sensor in the light path of this system. The SENSOR does not, in any way, change the characteristics of the optical system. THAT is my point. That the smaller sensor captures a smaller FOV than the larger sensor is a function of THE SENSOR, not the optical system. The only difference that will be introduced by the smaller SENSOR is the reduced FOV of the CAPTURE--i.e., the LENS STILL HAS ITS ORIGINAL FOV, it's just that the smaller sensor CANNOT CAPTURE IT (AL CAPS added for emphasis--not meant as shouting!).

pcasciola

20th of December 2004 (Mon), 19:53

I suggest the "crop the larger image to match the smaller" method to highlight the fact that smaller sensors DO NOT magnify more than large sensors. Period. If you want to add in other factors--like moving the shooters around--fine. But it does not change the fact that smaller sensors DO NOT magnify more than large sensors.
santhony@mn.rr.com
You are correct, the smaller sensor does NOT magnify the projected image from the lens more than the larger sensor. It simply resolves a smaller area of the same projected image at a much higher resolution than it's full frame counterpart, thereby producing more detail over the so called "cropped" area. Magnification means increasing the apparent size of an object, and if a higher pixel density over a given area is not magnification, I'm not sure what is. It's not magic as you said we like to call it, it's just advancements in technology.

Answer me this. What would be the difference between a full frame camera using a hypothetical 1.6x extender to "magnify" the same light that would be gathered by a 1.6x sensor camera? Not much, I think. You'd lose about a stop and a halfs worth of light with the extender, which is probably not that far off from what you lose with the smaller photosites on the smaller sensor. So, if they are nearly the same, are we saying extenders do not magnify either? If not, maybe Canon should rename their extenders to "crop devices".

Steven M. Anthony

20th of December 2004 (Mon), 20:20

You are correct, the smaller sensor does NOT magnify the projected image from the lens more than the larger sensor. It simply resolves a smaller area of the same projected image at a much higher resolution than it's full frame counterpart, thereby producing more detail over the so called "cropped" area. Magnification means increasing the apparent size of an object, and if a higher pixel density over a given area is not magnification, I'm not sure what is. It's not magic as you said we like to call it, it's just advancements in technology.

Answer me this. What would be the difference between a full frame camera using a hypothetical 1.6x extender to "magnify" the same light that would be gathered by a 1.6x sensor camera? Not much, I think. You'd lose about a stop and a halfs worth of light with the extender, which is probably not that far off from what you lose with the smaller photosites on the smaller sensor. So, if they are nearly the same, are we saying extenders do not magnify either? If not, maybe Canon should rename their extenders to "crop devices".

Who said the smaller sensor had higher pixel density than the larger? All of my comments (in the other thread slin100 referred to) were regarding sensors of equal pixel density (again, keeping an apples-to-apples comparison).

The answer to your "answer me this" question is that extenders are optical elements--by adding one to the optical system you change the optical characteristics of the system. One of the characteristics of the optical system they change is the magnification factor of the system.

I don't follow your case for the smaller sensor being akin to losing light due to an extender. The extender reduced light essentially evenly across the film/sensor plane (yes, there is some aditional drop off at the edges...). So the distribution of light is essentially equal across any sensor placed at the end of the system. For a lens of focal length x, a smaller SENSOR, while receiving the same DISTRIBUTION of light across its surface as a larger sensor, will receive less total light by virtue of its smaller surface area--i.e., light that would strike a larger sensor simply falls outside the perimiter of the smaller sensor.

And BTW--even with a smaller sensor of higher pixel density, while the resulting image could be enlarged to a greater degree without exhibiting greater loss of image quality (versus a larger, less pixel-dense sensor), the performance of the optical system remains unchanged, as I pointed out.

Pyromaniac

20th of December 2004 (Mon), 21:12

I just found this forum, and at the moment am still shooting on a 35mm EOS Rebel, but looking to make the upgrade to digital sometime soon(hopefuly). It seems to me that most of what is in this thread is just the same stuff being repeated over and over again by different people. Though I did only read about half of the post.

I have been doing research on the different digital SLR's from Canon. I like the 20D myself mostly because of the features of the camera and it's in a price range I can afford.

It seems to me that comparing the sensor size of digital cameras is like comparing the negative size of film cameras. Assuming shoot them all from the same spot, the bigger the negative the more of the subject you get in the final print.

I did think that it was a "magnifacation factor" before reading this thread.

Thats my 2 cents on the subject.

pcasciola

20th of December 2004 (Mon), 21:25

Who said the smaller sensor had higher pixel density than the larger? All of my comments (in the other thread slin100 referred to) were regarding sensors of equal pixel density (again, keeping an apples-to-apples comparison).

The answer to your "answer me this" question is that extenders are optical elements--by adding one to the optical system you change the optical characteristics of the system. One of the characteristics of the optical system they change is the magnification factor of the system.

I don't follow your case for the smaller sensor being akin to losing light due to an extender. The extender reduced light essentially evenly across the film/sensor plane (yes, there is some aditional drop off at the edges...). So the distribution of light is essentially equal across any sensor placed at the end of the system. For a lens of focal length x, a smaller SENSOR, while receiving the same DISTRIBUTION of light across its surface as a larger sensor, will receive less total light by virtue of its smaller surface area--i.e., light that would strike a larger sensor simply falls outside the perimiter of the smaller sensor.

And BTW--even with a smaller sensor of higher pixel density, while the resulting image could be enlarged to a greater degree without exhibiting greater loss of image quality (versus a larger, less pixel-dense sensor), the performance of the optical system remains unchanged, as I pointed out.
I agree, the sensor size and pixel density in no way changes the performance of the optical system, but there is no full frame sensor made today that equals the pixel density of any current Canon 1.6x sensor, so how can we say they are equal in pixel density? If the pixel density were equal I would agree with everything you are saying, and I'd be happy to call it plain cropping at that point.

I am only contending that the current 1.6x Canon sensors will provide more detail over the same area than any of Canon's larger full frame sensors because they are far more dense and of very good quality. I am in no way implying the smaller sensor is better, just that the smaller 8MP 1.6x sensor is able to resolve the "cropped" area at a higher resolution than any current full frame sensor, which I think is pretty close to what magnification is, whether it be optical magnification or magnification through higher pixel density.

Is it safe to say the 1Ds Mk II is effectively increasing the magnification over a 1Ds by resolving the image at 16MP instead of 11MP because the photosites are more dense? I believe so, because you can print the 16MP picture much larger and have the same detail as a smaller 11MP print. But at some point we are going to need higher resolution lenses.

Also, I think you misread my extender statement (Or I misread your explanation). I was saying that the amount of light lost on a full frame camera using an extender is similar (yet slightly less I agree) than the amount of light lost using the same lens on the smaller sensor camera which is NOT using an extender, assuming the extender ratio equals the difference in sensor size.

pcasciola

20th of December 2004 (Mon), 21:58

I have been doing research on the different digital SLR's from Canon. I like the 20D myself mostly because of the features of the camera and it's in a price range I can afford.

It seems to me that comparing the sensor size of digital cameras is like comparing the negative size of film cameras. Assuming shoot them all from the same spot, the bigger the negative the more of the subject you get in the final print.

I did think that it was a "magnifacation factor" before reading this thread.

Thats my 2 cents on the subject.

Welcome to the forum, and welcome to your first X-factor/crop factor/magnfication factor thread. There WILL be more, I can guarantee it.

You are correct in saying that the bigger the negative the more of the subject you get in the final print, but I don't think you can say comparing sensor size is like comparing film size, because currently the highest resolution APS-C sized sensor has higher resolution (pixels per square mm of sensor) than any of Canon's full frame sensors. If they were of equal pixel density then I would say you are 100% correct.

Take, for example, the 11MP full frame 1Ds compared to an 8MP APS-C sized 20D. With the 1Ds you are getting more of the subject with the full frame but at a lower resolution, because you are only getting 40% more resolution over 2-1/2 times the subject area.

Now, I'm not even beginning to imply I would rather have my 20D over a 1Ds, I just can't afford one right now. Well, I CAN afford one, it's just that I wouldn't be able to afford the divorce after my wife found out. ;-)

Steven M. Anthony

20th of December 2004 (Mon), 22:26

I agree, the sensor size and pixel density in no way changes the performance of the optical system, but there is no full frame sensor made today that equals the pixel density of any current Canon 1.6x sensor, so how can we say they are equal in pixel density? If the pixel density were equal I would agree with everything you are saying, and I'd be happy to call it plain cropping at that point.

I am only contending that the current 1.6x Canon sensors will provide more detail over the same area than any of Canon's larger full frame sensors because they are far more dense and of very good quality. I am in no way implying the smaller sensor is better, just that the smaller 8MP 1.6x sensor is able to resolve the "cropped" area at a higher resolution than any current full frame sensor, which I think is pretty close to what magnification is, whether it be optical magnification or magnification through higher pixel density.

Is it safe to say the 1Ds Mk II is effectively increasing the magnification over a 1Ds by resolving the image at 16MP instead of 11MP because the photosites are more dense? I believe so, because you can print the 16MP picture much larger and have the same detail as a smaller 11MP print. But at some point we are going to need higher resolution lenses.

Also, I think you misread my extender statement (Or I misread your explanation). I was saying that the amount of light lost on a full frame camera using an extender is similar (yet slightly less I agree) than the amount of light lost using the same lens on the smaller sensor camera which is NOT using an extender, assuming the extender ratio equals the difference in sensor size.

Well, I was only concerned with optical magnification--not effective magnification due to increased resolution.

As for your extender comment: My point was that the loss of light from the use of an extender is due to the reduced FOV of the optical system--and the reduced light from the use of a smaller sensor is due to part of the image created through the optical system falling outside the parimeter of the sensor. While the amounts might be similar in the case of a 10D vs a full-frame, there is no relation between the two. That is, the similarity is of no significance.

pcasciola

20th of December 2004 (Mon), 22:49

Well, I was only concerned with optical magnification--not effective magnification due to increased resolution.

As for your extender comment: My point was that the loss of light from the use of an extender is due to the reduced FOV of the optical system--and the reduced light from the use of a smaller sensor is due to part of the image created through the optical system falling outside the parimeter of the sensor. While the amounts might be similar in the case of a 10D vs a full-frame, there is no relation between the two. That is, the similarity is of no significance.

Yes, no argument from me there. Optical magnification remains unchanged when switching the same lens from full frame to a smaller sensor, and the only time "effective" magnification even becomes a question if when the pixel densities of the sensors are different.

Still not sure I am getting your point on the extender vs sensor crop though. Isn't the amount of light that falls off the area of a 1.6x sensor the same as the light you would lose if you were to use my hypothetical 1.6x extender on the same lens with a full-frame sensor? In both cases you are losing the same amount of FOV. I've seen the math that proves the smaller sensor is actually losing slightly more light than the if an equal ratio extender was used, but they were very close from what I remember.

Steven M. Anthony

21st of December 2004 (Tue), 00:01

Yes, no argument from me there. Optical magnification remains unchanged when switching the same lens from full frame to a smaller sensor, and the only time "effective" magnification even becomes a question if when the pixel densities of the sensors are different.

Still not sure I am getting your point on the extender vs sensor crop though. Isn't the amount of light that falls off the area of a 1.6x sensor the same as the light you would lose if you were to use my hypothetical 1.6x extender on the same lens with a full-frame sensor? In both cases you are losing the same amount of FOV. I've seen the math that proves the smaller sensor is actually losing slightly more light than the if an equal ratio extender was used, but they were very close from what I remember.

My point about the extender comments you made is "so what!" I can go to the beach and fill a pail with an amount of sand that will equal the weight of ornaments we put on our xmas tree. So what, again. I get how the math works--but it's nothing significant. Like I can get 6 as a result of 2 X 3 or 12/2.

MarkH

21st of December 2004 (Tue), 03:55

I would like to suggest that there is no magnification factor or crop factor with lenses when used on a D-SLR. All you have is a different angle of view captured then with a different sized sensor or piece of film.

Of all the formats to ever exist I think that 35mm film gained the most popularity and was the most common worldwide. Therefore there are a large group of photographers that understand what lens to use to capture what they want when using 35mm film. For these people there is a MULTIPLICATION FACTOR they can use to calculate the equivalent angle of view to 35mm with a lens when used on a D-SLR.

All this means is that a photographer that wants a lens that captures an angle of view that the 85 f1.8 on the 35mm camera captures, when using a 20D he would use a 50 f1.8 which would do a very similar job. The DoF will be a little deeper and he could opt for a 50 f1.4 to compensate. With a 50 f1.4 on a 20D the place you stand to get a certain shot (therefore the perspective) will not be much different to using an 85mm lens on a 35mm film camera. (50 f1.4 on 20D is not identical to 85 f1.8 on a film camera, but it is a close approximation for most purposes)

For those not familiar with how much scene a particular lens will capture when used with 35mm film cameras, I can't see how the multiplication factor is of any value to you. Saying that the 50mm lens acts like an 80mm lens won't really mean much to you.

I have never read anything from Canon or Nikon that refers to a magnification factor, only a multiplication factor. Magnification is easy and common, instead of printing at 4x6 try 8x12, that's 2x magnification.

Anyone who can't look at a scene and immediately know what lens they would use on a 35mm camera to get what they want in a photograph should just ignore the multiplication factor, it really is not important to you!

I think most people make too much of a fuss over this issue. When you use a l ens on a D-SLR the images that you get, well that's the result of what you are using. If you want wider angle then you buy a shorter lens (smaller mm number) when you want to capture a narrower angle you buy a longer lens (larger mm number). Why does this have to be so complicated?

Steven M. Anthony

21st of December 2004 (Tue), 08:46

The reason the 1.6 factor was mentioned in the first place was for those photogs who DO know what to expect from a lens of a particular focal length.

But you are right--to those who don't know what to expect from, say, a 50mm (35mm-format) lens, the crop factor isn't something they need be concerned with.

BTW: going from a 4X6 to an 8X10 is 4x magnification (think of how many 4X6 sheets will fit on an 8X10 sheet). Mathmatically, you are increasing each dimension 2x. And 2X2 = 4.

I think all of us discussing the issue know the end result--i.e., a narrower FOV. Some, however, seem to assign magical powers to the small-sensor set-up...

slin100

21st of December 2004 (Tue), 09:01

BTW: going from a 4X6 to an 8X10 is 4x magnification (think of how many 4X6 sheets will fit on an 8X10 sheet). Mathmatically, you are increasing each dimension 2x. And 2X2 = 4.

It is a 4x increase in surface area. When speaking of image magnification, I find that people tend to quote only one linear dimension. The other dimension is assumed to be scaled identically. There's no advantage to multiplying both factors when each factor is the same.

Steven M. Anthony

21st of December 2004 (Tue), 09:12

It is a 4x increase in surface area. When speaking of image magnification, I find that people tend to quote only one linear dimension. The other dimension is assumed to be scaled identically. There's no advantage to multiplying both factors when each factor is the same.

I get the assumption. But enlarging a 4X6 to an 8X10 IS a 4-times magnification--even if people think it is a 2x magnification... So I guess the advantage to multiplying both factors when each factor is the same is that you are actually describing what happens!

If you want a 2x magification of a 4X6, multiply each dimension by 1.414--that yiedls a 5.66 X 8.49. Objects in the 5.66X8.49 print will be twice as big as they are in the 4X6.

Jon

21st of December 2004 (Tue), 09:54

Steven, you're misusing "magnification". Magnification refers to linear values not areal values. Look at "magnifications" on macro lenses. 1/2 life-size won't yield you an image dimensionally .707x that of the subject; It'll be half the subject size. The formula for magnification compares subject and image dimensions. It doesn't consider areas of the subject and image. Enlargements are handled the same way; it's a linear value. The same applies to sensor resolutions; doubling the number of pixels in a sensor doesn't double its resolving power; it only increases it by 1.4x. But you would consider a 6 MP sensor to be able to resolve twice the detail as a 3 MP sensor of the same absolute area.

slin100

21st of December 2004 (Tue), 11:04

I get the assumption. But enlarging a 4X6 to an 8X10 IS a 4-times magnification--even if people think it is a 2x magnification... So I guess the advantage to multiplying both factors when each factor is the same is that you are actually describing what happens!

If you want a 2x magification of a 4X6, multiply each dimension by 1.414--that yiedls a 5.66 X 8.49. Objects in the 5.66X8.49 print will be twice as big as they are in the 4X6.
I understand your logic and it makes sense. IMO, your viewpoint is in the minority. If I zoom from 100 mm to 200 mm, have I magnified the image by 2 or 4 times? You will say 4, but I think most will say 2.

CyberDyneSystems

21st of December 2004 (Tue), 13:48

I just found this forum,

...It seems to me that most of what is in this thread is just the same stuff being repeated over and over again by different people....

Thats my 2 cents on the subject.

God Bless the Voice Of Reason ;)

MarkH

21st of December 2004 (Tue), 14:22

BTW: going from a 4X6 to an 8X10 is 4x magnification (think of how many 4X6 sheets will fit on an 8X10 sheet). Mathmatically, you are increasing each dimension 2x. And 2X2 = 4.

Canon and Nikon and other manufacturers have a different view to you. Check out the 1.4x and 2x extenders.

Scale modellers also disagree with you, check out a 1/24 scale model of a car in the closest hobby shop, notice that the model has a volume that is 1/13824 of the full sized car. I used to race 1/10th scale offroaders, they weighed about 1.5KG, the real cars could weigh over 1000KG. I had no problem understanding why my model didn't weigh over 100KG.

Most of us realise that when you magnify something 2x you have increased the area 4x. If you scale up a 3d object 2x then the volume will increase 8x.

Tomsk

21st of December 2004 (Tue), 14:57

I've only skimmed through this thread 'cos I got bored when it started getting technical. :!:

I don't start taking photos by thinking 'If I had a 35mm camera, a 50mm focal length would be ideal. Now 50/1.6=31.25, so I'll need to set the zoom to 31.25. But the perspective will be wrong so I'll need to get closer and set a wider zoom to compensate'. :confused:

All I know is I pick up my camera (300D), fiddle with settings, adjust zoom or change lenses as required, move about a bit and take the photo. :D

slin100

21st of December 2004 (Tue), 16:19

Steven M. Anthony

21st of December 2004 (Tue), 16:33

It seems I've seriously overestimated the interest level on this topic. I thought there were a significant number of people who had migrated from film SLRs. A fraction of those users have gotten comfortable using their film SLRs and no doubt figured out what apertures and shutter speeds to use to achieve the desired DOF and to minimize camera-induced shake. I thought these people would want to know what compensations to make after switching over to a DSLR.

The message I'm hearing is that people don't care about the technical "whats" and "whys". People seem to be happy relearning everything all over again. Perhaps the number of people who've used film SLRs in their past lives is much smaller than I believed.

You might be right on this, slin100. I, for one, like to know the whats and whys--but maybe most don't.

Also, from our off-line discussions, it is clear you are not one of the magnification factor magic thinkers! Seems we were each making different points.

As for magnification--2x vs. 4x--maybe I am in the minority. I just think in terms of 2 dimensions when it comes to photography, as it is a 2 dimensional medium (at least physically). To me, something is twice as big as the original if it has twice the surface area of the original. This wouldn't mark the first unconventional view I've held... :)

slin100

21st of December 2004 (Tue), 16:58

You might be right on this, slin100. I, for one, like to know the whats and whys--but maybe most don't.

Also, from our off-line discussions, it is clear you are not one of the magnification factor magic thinkers! Seems we were each making different points.
Steven,

Your acknowledgement gives me great pleasure. It's much appreciated.

r.morales

1st of August 2007 (Wed), 09:51

Thanks

wilvoeka

1st of August 2007 (Wed), 10:49

I didnt read through all the links, but there is one thing that always seems to be missing in these types of articles.

Even though the FoV may change by the size of the sensor, and the DoF may change slightly, one thing remains the same.

Lets use the 1.6 Crop as an example.

If you are portrait shooter and used a 85mm with film or a FF DSLR because you like the proportions in gave for a Headshot, then you still want to use a 85mmon the APS-C sensor.

If you are 6 feet from the subject and use a 16mm lens, even though the field of view is differant the subject will still be exagarated, and a 200mm will still have a slimming effect.

Compression and broadining charactoristics of a lens are not effected by the Sensor size. So it is important to still consider the effect you want and not just the FoV.

A 50mm my frame a subject like a 85mm on a FF, but if the 85mm is more pleasing to you then you need to use a 85mm and put more distance between yourself and the subject. This is where people with limited space have problems.