Digital lens Coverage

[phili1]

Ok I am told that on a digital camera you have to take into consideration the fact that a sensor is smaller then a 35 mm negative I have a so called
increse factor for 35 mm lenses attached.

Example: a 28 mm lens on a 35 will become a 44 mm on my 20D.

I do Real Estate and I use lenses for room Photography. I have a 17mm lens for my 20D ( which calculates to 27.2mm). I have done some test side by side with my EOS and find this.

It brings further away things in like a tele, from that aspect the crop factor works. But it allows me to get more of the room in then my 28mm lens did on my 35mm Camera.

So the question is just what happens when a 35 mm lens is used on a 1.6 factor digital Camera.

Anyone have the answer to this. I would be interested.

The other thing that confuses me is I hear everyone say 17 mm is no good for landscapes but I saw a test taken on a tripod and the difference between 12mm and 17mm is about 2 feet on the right and 2 feet on the left, not much more of the lanscape in the picture to make a difference.

[Kenski]

When a 35 is used it is equal to a 56mm


Just take 35 and multiple it by 1.6.... or just take ANYTHING and multiple it by 1.6 and it will give you what it will end up being...


a 17mm is a good lens for landscape...

[phili1]

I know how to multiply, I know that answer what I an doing is questioning weither it is 100% true, read what I wrote.

My 17 mm which is supposed to work as a 28mm on my digital Camera has a widere area of coverage why, if it is supposed to be 28mm.

[rkoshy]

As an added question.... wouldn't this affect the flash, since the lens will report its current length, and the camera would pass that onto the flash? This would cause the flash to be "short"... or am i wrong?

[Kenski]

As an added question.... wouldn't this affect the flash, since the lens will report its current length, and the camera would pass that onto the flash? This would cause the flash to be "short"... or am i wrong?

ETTL knows this and comps for it...

[Kenski]

I know how to multiply, I know that answer what I an doing is questioning weither it is 100% true, read what I wrote.

My 17 mm which is supposed to work as a 28mm on my digital Camera has a widere area of coverage why, if it is supposed to be 28mm.

Well, I can't read what you wrote there and you can't multiple.... 17x1.6=27.2 not 28 :)

[phili1]

Actually , It has a problem. If you are using a 17 to 35mm lens it knows 35mm but can't adjust for 17 so it sets it at 24mm. NO\ow here is the good part, is the 24 mm it sets it to the equivalent of 17 mm. It knows the lens is 35mm and sets it so, why not 50mm because a 35mm lens is actually 56mm.

There are allot of questions no one can answer with this digital system.

[HJMinard]

This thread is thoroughly confusing a simple subject.
Take your lens' mm and multiply by 1.6 - that is the effective "mm" of your lens.

what I am doing is questioning weither it is 100% true

It's true - there's no smoke and mirrors involved.

[Tomsk]

I know how to multiply, I know that answer what I an doing is questioning weither it is 100% true, read what I wrote.

My 17 mm which is supposed to work as a 28mm on my digital Camera has a widere area of coverage why, if it is supposed to be 28mm.

I assume you get your 35mm film developed and printed at a local store. If so you might find that the print is actually a crop of the negative. When you view the picture taken with your 20D, you are seeing the full frame of the sensor. This might explain why the 17mmx1.6=27.2 on the DSLR appears to show more than 28mm on 35mm film.

Also 27.2mm is wider than 28mm.

[ScottE]

A 17 mm lens takes exactly the same photo, regardless of what camera it is used on. It is just that the digital sensor on a 20D is smaller than the amount of film that is exposed on a piece of 35 mm film. You would get exactly the same photo if you cropped the centre portion from a picture taken with a 35 mm camera.

Calling a 17 mm lens on a digital camera a 28 mm lens is not correct. It is only a convenience for people who have used 35 mm cameras and have not been able to adjust their brains to think 20D. It also provides a common standard for comparing the framing of pictures taken with different cameras such as digicams (about 4.8x), Olympus DSLR (2x), Sigma DSLR (1.7x), Canon DSLR (1.6x - 20D, 1.2x - 1D II or 1.0X - 1DS II), Nikon (1.5x), 35 mm film (1.0x), 4.5x6 mm medium format (about 0.5x), etc. The only reason that 35 mm equivalents are used is that so many people are familiar with 35 mm cameras.

If you are using 20D, start thinking 20D and the 35 mm equivalent is meaningless.

The flash on a 20D, or any other Canon camera, is calibrated for that camera and adjusts the flash accordingly. Therefore a flash that will give 28 mm coverage on a 35 mm camera is just as capable as giving 17 mm coverage on a 20D.

If you want to make things more complicated, when you make a print from 35 mm film or put a slide in a frame for projection, a little bit of the original picture is cropped around the edges. Therefore a 28 mm lens on a 35 mm camera only gives the equivalent of about a 29 mm lens when printed.

[Kenski]

I know how to multiply, I know that answer what I an doing is questioning weither it is 100% true, read what I wrote.

My 17 mm which is supposed to work as a 28mm on my digital Camera has a widere area of coverage why, if it is supposed to be 28mm.

I assume you get your 35mm film developed and printed at a local store. If so you might find that the print is actually a crop of the negative. When you view the picture taken with your 20D, you are seeing the full frame of the sensor. This might explain why the 17mmx1.6=27.2 on the DSLR appears to show more than 28mm on 35mm film.

Also 27.2mm is wider than 28mm.


You know, I never thought about that either... So I guess you need to take the 35mm negative and scan it yourself and then compare it to a digtal shot....

I used to develop my own B&W all the time and always cropped my shots and never thought about it... ;) hahaha.... thanks for pointing that out!!

[phili1]

Thanks Scottie, you have the saame perception as I have. I thought it was me. I haver said that a tele thats 200mm cant pull it any closer and is n ot in fact really a 320mm lens, the bird is not any closer but I have been corrected by some for saying this. It is mthe erception of being closer because of the crop.

As far as comparing, I have a Nikkon film scanner, I print my own pics on my Eposon 2200 so I compare apples to apples.

Thanks again Scottie.

[Hellashot]

No. Covereage from a 17mm on a 10D/Drebel/20D is identical to a 28mm on a film camera.

And Kenski:
Your and my 550EX does NOT compensate for the different effective focal length of the lense. That is why canon came out with the 580EX. It is stated so in their literature about the 580EX. If you are using a 550EX on a 20D/Drebel/10D in order to have proper flash coverage you either need to use the manual zoom for focal length or use an appropriate flash exposure to compensate for the shorter distance the flash will go by automatic settings.

[CyberDyneSystems]

Oh good,

Another thread on the crop factor.. we needed another it's been hours...

:lol: :lol: :lol: :lol:

Kindly take a look at the -=READ FIRST=- "EOS STICKY " thread at the top of this forum and click on the "10,000 posts on the X-factor" link...

Wait .. I'll save you the trouble :wink:

-=CROP FACTOR=- 10,000 posts on the X-Factor (http://photography-on-the.net/forum/showthread.php?t=45388)

[phili1]

I have read most of them and what I had to say was a little different. We talk about X factor but what is it really has not beed addressed as far as I have seen.

Scottie's explantion falls into what I tought, allot of talk about something thats nothing.

I hear I will have when I get my ordered 100-400 Canon a 640mm lens wow, but you know what its not it still 400 mm because it doessssn't pull the distent birds in anymore then on a 35mm camera. All it does is crop it closer, it's not a MM increaser its is a cropping factor.

All I have read did not say anything about that, so Cyber Dan I am sorry if it got your goat but my question was not answered.

Now it is and it isn't. It is answered but it isn't an increas inlens MM.

[CyberDyneSystems]

No sweat phil.. I still can't find my own explanation on this back in the archives...

But in short.

There is no increase in magnification.. there is only a decrese in angle of view.

Any perceived increase in magnification is only created when we print, because we will be printing the "cropped" image at full size.. as opposed to a cropped size.

If you were to print all your images to formats that took into account the 1.6... (ie smaller peices of photo paper) then you would have images identical to a cropped area of a 35mm print.

So when someone says 20mm on a 1.6 = 32mm ... they are not saying that the lens is longer.. they are saying your resulting image will have the "Angle of view" of a 32mm lens on a 35mm film negative. (even if they don't know it when they say it)

I agree with Scotte!
IMHO None of it matters a hoot unless you have spent years working with 35mm film systems. If you have not.. or can simply forget about 35mm film.. then you can simply establish your own reference point with the equipment you use and ignore the 35mm film legacy.

The frustration level that this simple phenomenon seems to cause is what interests me.

The reason for the compilation of all these "X-Factor" threads is not only to have an answer when somone asks ready made.. (albiet that is a large part of the reason it was compiled) ...but also as a study of how on this issue it seems rare that any two minds will think alike!

Every ones seems to require a different ndividual frame of reference to which the matter must be appied. :?

It is a very odd thing indeed.

[pcasciola]

Until the resolution of the sensors exceeds the optical resolution of the lens, I think it's fair to say the crop is in fact increasing the magnification of the lens.

Everything else being equal, a 320mm lens on an 8MP full frame sensor will be pixel for pixel the same as a 200mm lens on an 8MP 1.6x sensor camera, assuming everything else about the cameras were the same of course. So, isn't that in fact increasing the magnification of a 200mm lens to 320mm, same as if you had a 1.6x extender on there (assuming there was a 1.6x extender of course)?

[phili1]

No that was my point. Increased magnification means it will pull a subject from further out in close. 200mm pulls 200 mm weither on a 35 mm or a digital 1.6 factor. It is the perception of magnification.

[Miika]

I have a question that relates to this dilemma... it's about perspective.

I've tried to search this forum with keywords "crop factor perspective", but I haven't really found the answer.

Let's say our beloved Canon 50 mm lenses are called "normal" or natural perspective lenses. Items further away look further away as your eye sees them in nature.

I read somewhere that what is called a normal lens on a particular camera depends on the size of its film format (frame size). Obviously this means the the lenses are designed for the particular frame size - and we can see this development also on digital format with the introduction of the new ultra-wide lenses.

My question: Is the picture of a 28 mm or 35mm lens on 1.6x camera equal to 50 mm on a 35mm film frame in terms of perspective?

Typical example of wide angle behaviour: a falling building when the camera is tilted to make the building fit the frame. The special character of optics of a lens doesn't change with cropping, does it?

On the other hand the crop factor cuts out some distortion or vignetting of some lenses.

Miika

[pcasciola]

Is the picture of a 28 mm or 35mm lens on 1.6x camera equal to 50 mm on a 35mm film frame in terms of perspective?


Yes. It's all about field of view (FOV) which is the angle of view/perspective. a 50mm lens on a 35mm camera provides a 40 degree angle of view. A 31mm lens would provide the same 40 degree angle of view, or perspective, on a 1.6x crop camera. So, a 28mm will be a slightly wider perspective, and 35mm would be slightly narrower than a 50mm on a full frame camera.

[pcasciola]

The other thing that confuses me is I hear everyone say 17 mm is no good for landscapes but I saw a test taken on a tripod and the difference between 12mm and 17mm is about 2 feet on the right and 2 feet on the left, not much more of the lanscape in the picture to make a difference.

Phili, regarding the 12mm - 17mm is only 2 feet statement, look at your own comparison pics that you took with the 10-22mm. On the house pictures, the 10mm vs 17mm shots were at least 100 feet different, and that was from only about 50 feet away. To say the difference between a 12mm and 17mm is 2 feet on either side is completely arbitrary, because that is only at 10-12 feet distance, not the typical landscape distance, which could sometimes be a mile or more, in which case you could literally pick up 1000 more feet on either side going from 17mm down to 12mm.

On a 1.6x crop camera, the angles of view are as follows:

10mm = 97 degrees
12mm = 87 degrees
17mm = 67 degrees

So, you can see, going from 12mm to 17mm you are losing almost 25% of your field of view, going from 87 degrees down to only 67 degrees. This means, if your target subject was 100 feet wide and would fit in 12mm, you would be losing about 25 feet of that picture by going up to 17mm.

I think that's why some people like myself, say that 17mm is not nearly wide enough on a 1.6x crop camera for most landscapes. Again, back to the crop factor, it's the same as a 28mm lens on a full frame camera, which was never considered a super wide lens.

[Hellashot]

In order to get 28mm of view of a film camera, you need a 17mm lens on a 20D/Drebel/10D, period.

[pcasciola]

In order to get 28mm of view of a film camera, you need a 17mm lens on a 20D/Drebel/10D, period.

Yeah, what he said.....

I like the way you were able to say in under 20 words what took me an entire page to attempt to explain. :lol:

[phili1]

Phil C I was on an angle if you look at the left side its slight but the right side is great that is caused by the angle of view. Perspective. If you look at the rooms its not that drastic and my comment was 12mm verses 17 mm, now if you mentally cut it half what do you have about 2 feet on either side.When you tilt a wide angle you will get a distortaion. I am only reporting how someone put the Sigma 12-24 on a tripod took 1 pic at the landscape another at 17 mm and a third at 24mm. The difference in the landscape was 2 feet on either side and that amazed me.

Now about the 28 mm lens and the 17, that is what I am debating. If I take my Eos with my 28 to 105 and view my room amd take a picture I do not get in as much as I do with my 20 d with my 17mm lens and based on crop factor its supposed to be the same.

So you can tell me its the same but I can not see where it is.

Hey you have been telling me that I have a 640mm lens and I don't, it does not pull in anything any closer, it just crops.

See thats my delema, I hear you but it does not compute?

and this statment just isnt fact (In order to get 28mm of view of a film camera, you need a 17mm lens on a 20D/Drebel/10D, period.) or I can't see where it is or did you convince me with facts. The 28mm gives the same field of view but the sensor crops it. That does not make it a 44 mm lens. Hey I am stubborn.

I am not trying to be a hard nose but I have sat back and listened and it does not compute in my book, there is someting missing.

I bought the 10 to 22 Canon which I did not like because everyone said to get wide you need 10mm, not so 17 does a good job 12 is bettrer and 10 is distorted so what good is it, I might as well buy a fish eye prime its sharper.

Anyway this is my last post as you all have answered my qiestions, thanks for the help.

[Jon]

and this statment just isnt fact (In order to get 28mm of view of a film camera, you need a 17mm lens on a 20D/Drebel/10D, period.) or I can't see where it is or did you convince me with facts. The 28mm gives the same field of view but the sensor crops it. That does not make it a 44 mm lens. Hey I am stubborn.

The angle of view is what you get on the sensor, not what the lens is capable of covering. With the smaller sensor of the 10D/20D, a shorter f.l. lens will provide the same angular coverage on the 15 x 22.5 mm sensor that a 28 will on a 35 mm 24 x 36 mm frame. If you take a 200 mm lens on an 8" x 10" view camera, is it still a 12 degree (diagonal) angle of view? Not if it's designed for 8 x 10.

[pcasciola]

Now about the 28 mm lens and the 17, that is what I am debating. If I take my Eos with my 28 to 105 and view my room amd take a picture I do not get in as much as I do with my 20 d with my 17mm lens and based on crop factor its supposed to be the same.


Well, 17mm on a 1.6x crop is 27mm not 28mm. It doesn't sound like a lot, but the 17mm w/1.6x crop is still almost 5% wider. 3% wider to be exact. If you include the fact that these mm ratings are rounded, the 17mm could actually be 5% wider than a 28mm on a full frame camera.

Plus, you are going in circles with the 2 feet comment on your small room shots. I understand the 17mm works for you, but your comment was that you can't understand why landscape photographers say 17mm is not enough, and that is what I was explaining to you. 2 feet is only the difference at a very short range. Landscape photographers can see a half a mile width difference at times, just as you were able to fit an entire other house in from only 50 feet away. Ok, maybe your perspective was a little different, but you have to admit the width is FAR more than 2 feet.

[phili1]

Phil C at 10 mm yes at 12mm no. and I understand that you get more coverage angle but you cant tell me that at 10 feet there would be a 2 foot differenc but at 100 feet it would grow, I forget what mathmatics it relates to but look at this chart. Both lenses should follow the same path and maintain that bases through out the entire range. I am not sure what the angle of degree is but this chart shows what I mean.

http://www.pbase.com/image/36583041/medium.jpg

Again I am not contesting, that wider is better but the Canon 10mm is disstorted and Sigma s 12 mm is not, that 2 mm is not much and all; I am saying is 17 mm is n ot that bad if you have to settle, anyway I did n ot start this thread over this, my comments were about conversion of 35mm to digital and I have to say I half did it because not one person took the time to really read what I said but comment on something different.

Sorry to start this carma I will not voice my opinion anymore, but read your comment and look at this chart and comment to me. My statement was not outragous, it was only an obsevation on my part and I would love to have a wider lens but the Canon does not do it and Sigmas 12 - 24 has no front lens protection, so what should we buy, a 17 to 40 Canon or a 17 to 35 Tamron, nothing else left. Thats is what I am saying.

[Miika]

EDITED: LINK TO ANGLE OF VIEW CALCULATOR
http://www.mat.uc.pt/~rps/photos/angles.html

lens: film AOV => 1.6x crop factor camera AOV
according to the calculator linked above

(diagonal angle of view)

14 mm (Sigma): 114.2 degrees (film) => 88.4 degrees (15.1x22.7 mm 1.6x crop)
16 mm (16-35L): 108.2 degrees (film) => 80.7
17 mm (17-40L): 104 degrees => 77.3
20 mm (20-35): 94 degrees => 68.4
24 mm: 84 => 59.1
28 mm: 75 => 51.8
35 mm: 63 => 42.5
50 mm: 46 => 30.4
85 mm: 30 degrees (@35 mm) => 18.2 degrees (@ D10,D20 etc)

Lens AOV information according to product specs.

EDIT: Snipped out bogus chit-chat. I try to be more careful for now on...

My interest is still how the 28 and 35 lenses compare to 50mm@film


Miika

[pcasciola]

Whoah, hold up a sec. It looks like you quoted all the diagonal FOVs for the 35mm, but horizontal for the 1.6x crops.

My chart shows diagonal angle of view for 1.6x EOS lenses as follows:

10mm = 108
12mm = 97
14mm = 89
17mm = 78
24mm = 59
28mm = 52

28mm prime on a full frame is 75 degrees diagonal like you said, but anything 17mm and below is wider on a 1.6x crop. And those calculations match nearly exactly to the straight mm to crop calculations I did between the 17mm on a 1.6x vs. a 28mm on a full frame, which showed the 17mm to be a little less than 5% wider than a 28mm on a full frame camera.

[Miika]

The angle of view figures of different lenses at some focal lengths (for film) in my posting above are directly from product specs that can be found on websites of Sigma and Canon.

MISTAKE: To get the 1.6x figures I have simply divided

Film (diagonal AOV) 104 degrees / 1.6 = 65 degrees (still diagonal).

As there is the approximately 1.6x difference between the size of film and D10 sensor (same scale horizontal, vertical and even hypotenuse (diagonal); doesn't the angle of view change with the same proportion?

EDIT: Answer to this question is: NO!

Miika

[phili1]

You made me hunt and I think the rest of the world is as confused as this subject is.

Her is one web angle chart for 35mm

12 mm Independent 113 - Sigma 122 - Phil C 97 - MIika 114
17mm ------------ 93---- --------- 103 --------78 -------- 104


Which on is right, who is right Miika corresonds to Sigma, Phil your is different then the other two. and the independent is by itself.?????????

[CyberDyneSystems]

:lol: :lol: :lol:

This is priceless :D

[MarkH]

Phil C at 10 mm yes at 12mm no. and I understand that you get more coverage angle but you cant tell me that at 10 feet there would be a 2 foot differenc but at 100 feet it would grow, I forget what mathmatics it relates to but look at this chart. Both lenses should follow the same path and maintain that bases through out the entire range. I am not sure what the angle of degree is but this chart shows what I mean.
http://www.pbase.com/image/36583041/medium.jpg

Sorry dude, but that diagram is just plain wrong!

If at 10 feet away from the focal point there is a 2 feet difference then at 100 feet away the difference will be 20 feet.

Your diagram should have a focal POINT and the lines coming out from that, the lines will all converge on that point and will NOT be parallel.

What are you thinking? At 10 feet away if a wider lens can photo 2 feet more of a room do you really think that at 2 kilometres away you will only get 2 feet wider? What about 20 kilometres, still only 2 feet?

As to the difference between full frame at 28mm and digital at 17mm, they should be quite close, the 1.6x crop factor is not exactly 1.60000000, the 17mm and 28mm are not exact either, but is there really much difference in the resulting images in your experiment?

[pcasciola]

:lol: :lol: :lol:

This is priceless :D

Yes, it is. I have never seen so much bad math thrown around since that thread where people couldn't figure out that a 1.4x extender stacked with a 2x extender would give you 2.8x magnification. 3.4x was my personal favorite answer on that one. :lol:

Thankfully, MarkH got something right on this thread. That 12mm/17mm diagram is the worst error in mm to angle of view I have ever seen. It actually tries to show that 12mm and 17mm are at the SAME angle. That is absolutely hysterical. All that chart shows is two 17mm users, with one standing about 5-10 feet behind the other.

Sigma quotes 122 degrees for their 12mm because that is the diagonal angle of view on a full frame camera. On a 1.6x camera it's 97 (give or take a degree). The "independent" number is just plain wrong, and basic geometry shows that you can't multiply angle by the crop factor to get the adjusted angle like Miika did.

On the 17mm, again, Sigma quotes 103 which is correct on a full frame camera, 78 is the adjusted diagonal angle of view on a 1.6 crop camera, and the other 2 are just bad math.

I give up. I think the only thing we are proving is that photographers make poor mathematicians. :lol: :lol: :lol:

[pcasciola]

I dug up the math calculation for angle of view. This is a proven calculation, not a theory. Time for a little math.

angle of view = 2 * arctan(film size / (focal length * 2))

Let's calculate horizontal angle of view since the horizontal film sizes are more readily known values than diagonals. Full frame is 35mm horizontally, so for a 17mm lens:
angle of view = 2 * arctan(35 / (17 * 2)) = 90 degrees

on a 1.6x crop camera (APS-C sensor is 22.5mm wide), it's
2 * arctan(22.5 / 17 * 2)) = 67 degrees

Since angle of view effectively defines our magnification, we have just proven that crop factor decreases angle of view, thereby effectively increasing magnication. It does not increase the resolution of the lens, however, which is where the debate comes in.

I also drew some pictures of my own to help illustrate this.

Angle of view of 17mm lens on full frame vs 1.6x crop. As you can see, the width difference increases constantly as we move further out, not a constant 2 feet like some other charts incorrectly show.
http://www.casciola.com/pics/angle1.gif

Acquiring an object with a 17mm lens on a full frame camera:
http://www.casciola.com/pics/angle2.gif

Acquiring the same object with a 17mm lens on a 1.6x crop camera:
http://www.casciola.com/pics/angle3.gif

Another view. The photographer with the 17mm lens on a 1.6x crop camera (green) is standing further away from the object, and has a completely different field of view than the photographer with the 17mm lens on a full frame camera (blue) standing closer to fit the same object in frame
http://www.casciola.com/pics/angle4.gif

We've proven here again that we can stand further away with a 17mm lens on a 1.6x crop camera and acquire images that are further away, thereby increasing magnification same as if we were using a 28mm lens on a full frame camera, very different than pure cropping.

[phili1]

Ok Phil C now I will pull your chain one more time. How do I know your right and how and with what expertise can you state the independent is wrong. Who does one listen to and that is what goes on all day long here allot of people making statements about things that are not necessaraly right.

By the way sorry for misquoting your figures, and Mark I know my chart was wrong.

I started this post with the tele comversion question that was ligitimate and was a question in my mind and all of a sudden you guys took it somewhere else, so I played a devils advicate for awhile and poked and proded.

Phil C I have read some of your comments and know you have knowledge but in three different post your 17 mm wider lens has popped in and I know you are pissed because there is no alternative for you yet but maybe Tamrons new 10mm will fill the bill.

But just for the fun of it comment on these shots

12 Sigma @ F 16
http://www.pbase.com/dhatchner/image/28423546

17mm F 16

http://www.pbase.com/dhatchner/image/28423548

They are not my pictures, these were done by a David Hatcher. Look at the mountain in the distence. Not that drastic of a difference.

That was my orignial comment.

[CyberDyneSystems]

Phil1,

You ask "how will you know" if what is said is correct.

Well.. you don't know.. especially if one is not equipped to grasp the truth from the chaff (and I am not indicating that you aren't... only that indeed on a forum there will be individuals who won't be)

But if evidence such as PhilC has taken the time to provide for you is of no use to you based on your scepticism.. than I have to query.. "why ask in the first place?"

You've essentially said that we can not prove to you one way or another.. so then why waste the time and space and bandwidth on the thread?

:?

[pcasciola]

Phili, are you arguing the math? If you can prove that calculation wrong I'd love to see it. It's being taught in colleges around the world so I'm sure they'd be interested too.

I'd love to comment on those sample pictures, which I've also come across while evaluating my super wide options, and prove the point exactly. The tree and mailbox are about 30-40 feet away, and there is about 6-7 feet more view on either side at that distance. And, about that mountain in the background, you think that's not that big a difference?!?!?! That's about a mile more on either side at that distance. 12mm shows the whole mountain and 17mm cuts it in half.

[phili1]

First my comment was sent before phil C chart. Second I am not arguing the math I conceded you were right, in fact I knew you were right to start off.

My commnet was how does one know who to listen to. It was not for Dan or Phil C. I have seen allot of comments on this foum that was made up of pure conjecture. I got upset because my post went away from what I had posted to this.

Phil C that mountain has to be maybe 10 miles away or more, Can you tell me in the whole scheme of things the difference between the two pictures makes the 12mm shot that much more dramatic. Not to me and it may be a mile difference but in the photo or the screen it is only and inch.

Anyway I did appologies, sorry for baiting you, sorry for doubting you, sorry I started the whole thing.

[CyberDyneSystems]

That looks like a perfect way to conclude this thread.

CDS