Bigger or Smaller with x1.6

[OpenC]

I'm sure this has been covered before, but a quick search yielded nothing.

I read this on FredMiranda in a review of the 100-400:

I bought this lens about 6 month back prior to an African safari trip and it was used for 95% of my shots on the trip. I used it with a 30D which being a 1.6 frame gave me an effective 640mm reach.

The question is quite simple. Did (s)he actually have an effective 640mm reach, or did he in fact (as I suspect) just have a small crop from what remained a 400mm reach? I know we bandy about the "x1.6" thing, but is there actually any multiplying going on..?

If I look at my monitor from here, and then use my hands to partially cover my eyes so I can only see the image from the middle of the screen, surely I'm getting the same effect? I'm no closer, there's no additional zoom, but I'm seeing less of the image.

[Ves]

No multiplying.. the image is just cropped to what a 640mm would show on a full frame camera. No additional zoom, just cropped.
So let me try to clear this up both for myself and the sake of this thread..

1. You take a picture with a 400mm lens on a fullframe camera. Resize it to 500x___ pixels.
2. You take a picture with a 400mm lens on a 1.6x crop camera. Resize it to 500x___ pixels.
3. You take a picture with a 640mm lens on a fullframe camera. Resize it to 500x___ pixels.

#1 would look further away. #2 and #3 would look the same. So either way.. a 1.6x body crop would be better for a longer shot. You could always use a fullframe camera but then you'd probably need to crop it in the end.

[Glenn NK]

"The question is simple".

I think the answer is too - yes.

A smaller sensor "uses" or "sees" a smaller part of what the lens "sees" with a larger sensor. The smaller sensor uses a smaller angle of view. That's what long lenses do - they see a smaller angle of view.

So in effect a 400 mm lens becomes a 1.6 x 400 = 640 mm lens.

[OpenC]

"The question is simple".

I think the answer is too - yes.

A smaller sensor "uses" or "sees" a smaller part of what the lens "sees" with a larger sensor. The smaller sensor uses a smaller angle of view. That's what long lenses do - they see a smaller angle of view.

So in effect a 400 mm lens becomes a 1.6 x 400 = 640 mm lens.

Well, that's how I first thought about it. And I'm at great pains to point out that I really don't understand any of this properly... but am I right in thinking a FF camera taking a picture of something with a (theoretical) 640mm lens will give a better image than a x1.6 camera taking a picture of the same thing @ 400mm? After all, there aren't any extra optics involved in the x1.6. It's effectively just digital zoom which makes it a 640mm equivalent (and realistically, it's not even that: it's just a bit cut out of a bigger picture).

Essentially, this is how I understand it: the theoretical 640mm on a FF, and the actual 400mm on a x1.6, are not exactly the same in terms of resolution or definition: they just get the same things in frame. The 640mm magnifies better, and will give a better image. That's how I look at it, anyway. Right or wrong..? I'm fully prepared to be corrected on this, because I've never really understood it :)

That's what long lenses do - they see a smaller angle of view.
This is where it gets complex for me, you see. They do see a smaller angle of view, granted: but they also magnify the image more. The 400mm will never magnify like a 640mm just because it's resolving onto a smaller sensor, so you can't really say that 400mm = 640mm just because you're using a crop sensor.

I think that this concurs with Ves's post above, but I'm not entirely sure >_<

[grego]

Well, that's how I first thought about it. And I'm at great pains to point out that I really don't understand any of this properly... but am I right in thinking a FF camera taking a picture of something with a (theoretical) 640mm lens will give a better image than a x1.6 camera taking a picture of the same thing @ 400mm? After all, there aren't any extra optics involved in the x1.6. It's effectively just digital zoom which makes it a 640mm equivalent (and realistically, it's not even that: it's just a bit cut out of a bigger picture).


Not really. It's easier to achieve correct focus if you can fill the frame of the camera. You'll actually have more detail if you fill the frame of the photo as well. It's also cheaper to get better quality out of 1.6 with long lens.

Like the 300 2.8 is not going to have as long of a field of view on full frame. But on the 1.6 crop, its like having near the 500L with f/2.8. Yes, you can crop on something like the 5D, but making sure you got the AF correct on a smaller image is more difficult. It's less likely.

[chris clements]

search yielded nothing.

Are you having any better luck with Emilia Earhart or Osama Ben L ???

[SkipD]

No multiplying.. the image is just cropped to what a 640mm would show on a full frame camera. No additional zoom, just cropped.
So let me try to clear this up both for myself and the sake of this thread..

1. You take a picture with a 400mm lens on a fullframe camera. Resize it to 500x___ pixels.
2. You take a picture with a 400mm lens on a 1.6x crop camera. Resize it to 500x___ pixels.
3. You take a picture with a 640mm lens on a fullframe camera. Resize it to 500x___ pixels.

#1 would look further away. #2 and #3 would look the same. So either way.. a 1.6x body crop would be better for a longer shot. You could always use a fullframe camera but then you'd probably need to crop it in the end.There's an error in your thinking. Don't consider resizing the images to any pixel count. Pixel count has nothing to do with the image differences between a "full-frame" (or 35mm film) camera and a "crop" camera.

To correct your comparison:

1. You take a picture with a 400mm lens on a fullframe camera. Print the full image to 4x6 inches.

2. You take a picture with a 400mm lens on a 1.6x crop camera. Print the full image to 4x6 inches.

3. You take a picture with a 640mm lens on a fullframe camera. Print the full image to 4x6 inches.

NOW, your statement that "#1 would look further away. #2 and #3 would look the same" is quite correct.

The problem with a lot of the thinking in this thread is that a lens designed for 35mm film cameras "becomes something else" when you put it on a 20D. This line of thinking is totally false. The "crop factor" is only a comparison between two different formats. The term "format" refers to the size of the film frame or the digital sensor in a camera.

Please read this thread (http://photography-on-the.net/forum/showthread.php?t=45388) to better understand the "crop factor" thing.

By the way - quite a few people seem to believe that the EF-S lenses (and third-party lenses for "crop" cameras) do not function the same as EF lenses with similar focal lengths. This is definitely an incorrect assumption. Any lens with a 50mm focal length, for example, will provide the same image on the same body. By that, I mean that if you put an EF-S 18-55 on a 20D and zoomed to 50mm you will get precisely the same image size as if you put an EF 50mm prime or an EF 24-70 zoomed to 50mm on the same body.

[Hellashot]

I'm sure this has been covered before, but a quick search yielded nothing.

I read this on FredMiranda in a review of the 100-400:

The question is quite simple. Did (s)he actually have an effective 640mm reach, or did he in fact (as I suspect) just have a small crop from what remained a 400mm reach? I know we bandy about the "x1.6" thing, but is there actually any multiplying going on..?

If I look at my monitor from here, and then use my hands to partially cover my eyes so I can only see the image from the middle of the screen, surely I'm getting the same effect? I'm no closer, there's no additional zoom, but I'm seeing less of the image.

You are exactly right! Small sensor dSLRs like the 30D, Drebels don't see everything full frame/film lenses see. You can get the same field of view by taking a full frame dSLR and cropping it down a lot. You can make a 50mm FF shot look like it was taken on a 200mm lens if you crop down to 275 dpi 4x6 print (or so) It's funny. I'd rather record everything and have the ability to selective crop later than have my camera do it for me.

I read a post by a nikon user that was basically: I love the 1.5x factor of nikon, it allows me to use a less noticable shorter lens but get more reach than if I were using a FF camera. How funny. You could do the same thing with a FF camera - use that same lens as the nikon user and crop it later to make it look like it was taken on a longer lens! :)

Not really. It's easier to achieve correct focus if you can fill the frame of the camera. You'll actually have more detail if you fill the frame of the photo as well. It's also cheaper to get better quality out of 1.6 with long lens.

Like the 300 2.8 is not going to have as long of a field of view on full frame. But on the 1.6 crop, its like having near the 500L with f/2.8. Yes, you can crop on something like the 5D, but making sure you got the AF correct on a smaller image is more difficult. It's less likely.

Depends on what size you print. Photography is all about printing. :) If you're printing 4x6 or 5x7 you only need at more 2.5MP and if you print those sizes you should resize your pictures to that print size at 300dpi which greatly reduces how many pixels your image has. So for those print sizes your argument goes out the door.

And a 30D shot with a 300mm will not stand up to a 5D shot with 500mm for detail. :)

[jra]

Here's a pic that may help explain it....the circle is the image circle projected by the lens, the larger rectangle is a full frame sensor, the smaller would be a crop sensor....

http://i65.photobucket.com/albums/h223/jra2212/353Crop_Factor_Illustration_jpb-med.jpg?t=1168100677


edit....I didn't notice that the link to the topic that contains this photo was already posted above.

[Keith R]

Excellent explanation from Skip - hopefully making clear to all that you absolutely do not actually get extra reach by using a crop factor camera body.

It's called crop factor, as opposed to magnification factor, for a reason.

[thekid24]

Excellent explanation from Skip - hopefully making clear to all that you absolutely do not actually get extra reach by using a crop factor camera body.

It's called crop factor, as opposed to magnification factor, for a reason.

I agree,it just appears to give added zoom.It doesnt literally give a person that extra reach

[SkipD]

There is an undisputable fact that has not been mentioned here.....

If you take a shot with a 20D (an 8.2 megapixel camera) you will have more resolution than a cropped shot from all of today's "full-frame" DSLR cameras. This is assuming you are cropping the "full-frame" image to give you the same image with the same lens on the two bodies.

Since the area of the 20D's sensor is roughly 39% of a "full-frame" DSLR's sensor, you would need a 21 megapixel "full-frame" camera to give you the same pixel count (from the cropped "full-frame" image as the image from the 8.2 megapixel 20D.

While the resolution in the above scenario will definitely be better from the 20D, it is possible that other factors (such as pixel size in the camera) may make the cropped image from the "full-frame" camera appear to be as pleasing in most common print sizes.

[OpenC]

Thank you for all the responses.. :)

a 30D shot with a 300mm will not stand up to a 5D shot with 500mm for detail. :)

That's the fundamental thing for me. As long as that statement is true (which is what I thought originally), then all my questions are answered... although Skip's post above (which also makes perfect sense) seems to dispute it.

[SkipD]

And a 30D shot with a 300mm will not stand up to a 5D shot with 500mm for detail. :)This is quite true, but also very different from my post describing the pixel resolution differences.

My statement referred to using the same lens on both camera formats and cropping out everything from the "full-frame" image other than what was captured in the APS-C image. In this scenario, the APS-C image will have far more pixels than the cropped "full-frame" image.

For amateurs needing long focal lengths, using the APS-C format makes sense as you can get better resolution in photos of distant objects with shorter AND THUS LESS EXPENSIVE lenses than you can using a "full-frame" DSLR and cropping. The longer lenses required to fill a "full-frame" image with the same subject material can get quite pricey.

[PacAce]

Thank you for all the responses.. :)



That's the fundamental thing for me. As long as that statement is true (which is what I thought originally), then all my questions are answered... although Skip's post above (which also makes perfect sense) seems to dispute it.

No, Skip's post doesn't dispute what you stated. It just takes the discussion one step further. :)

[Jonathan Consiglio]

http://www.the-digital-picture.com/Canon-Lenses/Field-of-View-Crop-Factor.aspx

This should help anyone that is having a problem understanding FOVCF..
The higher pixel density of the FF sensor will yield higher quality images when cropped than if shot with a cropped sensor.. The FF sensor records more detail than an APS-C sensor..

[SkipD]

Ok... I'm trying to do this 100% crop bs in Photoshop CS2, and it's driving me insane.. Can someone tell me what to do that would show the quality difference between the 5D and 20D's sensors... At 100%, it's very hard to see a difference..Jonathan, you are on the wrong track. You cannot compare pixel-level viewing on the screen and make any sense of the difference.

What you need to do to truly compare the resolution is take two photos with the same lens on a 5D and on a 20D. Then, crop the image from the 5D until what is left is precisely what is on the image from the 20D. Then, PRINT the whole image from the 20D and the remaining cropped image from the 5D to the same size print. I suggest an 8" x 12" print or larger to show any differences. The pixel count should be on the order of 5 megapixels for the cropped 5D image and 8.2 megapixels for the 20D image.

[Phil Light]

...The pixel count should be on the order of 5 megapixels for the cropped 5D image and 8.2 megapixels for the 20D image.

Ok, now I'm getting confused. Are you saying Skip that technically you get better resolution from a 20D or 30D than you do from a 5D? If this is the case wouldn't the 20D or 30D camera be a much better value in every way than the 5D? Say it ain't so!!! I just sold my 30D to buy a 5D. :shock: Am I an idiot? :o

[chris clements]

Ok, now I'm getting confused. Are you saying Skip that technically you get better resolution from a 20D or 30D than you do from a 5D?

Stand in the same spot and use the same lens at the same focal length on a 20/30D and a 5D. Back on your computer, crop the 5D image down till it shows exactly the same content (same angle of view) as the full-frame 30D image. Then the 30D image will contain about 3mp more.

In the real world, of course, you'd zoom the lens or use your feet to get the same AoV. Then the 5D's extra (and, just as important, 'larger') pixels will come into play and see off the 30D.

[OpenC]

Ok, now I'm getting confused. Are you saying Skip that technically you get better resolution from a 20D or 30D than you do from a 5D? If this is the case wouldn't the 20D or 30D camera be a much better value in every way than the 5D? Say it ain't so!!! I just sold my 30D to buy a 5D. :shock: Am I an idiot? :o

...which is exactly what confused me in the first place. If all this was true, then surely the only area in which a FF camera would score is with ultra wide angles that the crop cameras can't get (and even then, my 10-22 is only 6mm away from the real thing). Surely every sports and nature photographer in the world would be using crop cameras, if they really did give better images at range than FF ones do.

I'll not pursue this further for fear of riling those who genuinely know what they're talking about :) I remember one day about five years after I'd started playing guitar that scales just suddenly made perfect sense to me, and I'm sure this'll work the same way. It's good that other people than me struggle with this concept, though :)

[chris clements]

I just sold my 30D to buy a 5D. :shock: Am I an idiot? :o

If you shoot predominantly sports/action and wildlife, then the answer is "yes". The 30D shoots/processes faster, and the extra 'throw' caused by the smaller sensor gets you closer to the action.
If you shoot predominantly portraits/scenery/interiors etc. and use your wider lenses more often then you've made the right move.

Since they compliment one another, personally I'd've kept both bodies.

[chris clements]

... then surely the only area in which a FF camera would score is with ultra wide angles .

Surely every sports and nature photographer in the world would be using crop cameras,

Only if you don't/can't move your shooting position or don't zoom/change lenses appropriately.

Most still ARE using crop cameras for this very reason , unless they've got the luxury of very long (& expensive) lenses.

[Phil Light]

...which is exactly what confused me in the first place. If all this was true, then surely the only area in which a FF camera would score is with ultra wide angles that the crop cameras can't get (and even then, my 10-22 is only 6mm away from the real thing). Surely every sports and nature photographer in the world would be using crop cameras, if they really did give better images at range than FF ones do.

I'll not pursue this further for fear of riling those who genuinely know what they're talking about :) I remember one day about five years after I'd started playing guitar that scales just suddenly made perfect sense to me, and I'm sure this'll work the same way. It's good that other people than me struggle with this concept, though :)

I don't want to get anybody riled :) , but I do want to pursue the subject. I may be exposing my ignorance (again) but if what Skip seems to be saying is true, (which btw I am not by any means doubting his technical expertise) why would anybody buy a 5D? Given the fact that it sells for almost 3 times more than a 30D What then is it offering? I based my decision on the fact that it is full frame, 12.something MP which owners almost unanimously praise the quality here daily. Even Ken Rockwell, an avid Nikon enthusiast says the quality of image that the 5D produces is incredible, better than all of his comparable Noinks. Again, I'm just hoping I didn't do a stupid thing in an attempt to get better image quality. Help? :cry:

[chris clements]

Why would anybody buy a 5D?
Because unless we're stalking bigfoot or are seated in Row Z of the stadium, we can always walk a bit closer and/or turn or zoom ring :)

[chris clements]

I didn't do a stupid thing in an attempt to get better image quality.
It's all down to what you shoot :)

[OpenC]

(edit)

(no need for this post, given the new ones above)

[Phil Light]

If you shoot predominantly sports/action and wildlife, then the answer is "yes". The 30D shoots/processes faster, and the extra 'throw' caused by the smaller sensor gets you closer to the action....

Nah, I do shoot sports sometimes, in fact frequently, but I can't remember the last time 3fps wasn't fast enough for me. But again, I don't do it professionally.

Since they compliment one another, personally I'd've kept both bodies.

I would have loved to have kept both bodies but the only way I could afford to move up(?) to the 5D is to sell the 30D. If funds allow I would not hesitate to buy another 30D down the road. It has been the best camera I've ever owned.

I would love to hear from someone who has made the move from a 20D or 30D to a 5D. Was it a good move?

[Phil Light]

Jeff, what do you think looks better? I know that the images from my 5D need less PP than from my 20D.. I know the images are cleaner... And a big thing for me, is how shallow I can get the DOF ove the smaller sensors...

I'll have to get back to you on this question. My 30D just sold yesterday & I haven't even boxed it up to ship it yet. I was going to order the 5D today from B&H. All of a sudden I'm starting to think I need to re-order another 30D. :rolleyes:

[Phil Light]

Anyone that doesn't understand why we'd buy a 5, and doesn't see the benefits, needs to rent one for about two weeks and post back then! It is far superior to the 20 or 30D.

Ok, I'm starting to feel a little better. I believe you are going to be a better judge than most, having both cameras.

[chris clements]

Was it a good move?

Absolutely. It's a killer for portraits & weddings. Skin tone rendition is just amazing. And the larger receptors mean that control of noise is phenominal (not that the 30D isn't a class leader). One proviso; you need good glass (not exclusively 'L' ) to get the most from the FF sensor.

But my 20D still gets dusted down occasionally when birding or at soccer matches.

[Phil Light]

YES! It was an incredible move! It has cut my PP time in half.. The 5D can handle things that the 20 or 30 can't.. Detail... Low Light... Wide Angle (if that's what you like)... AI Servo Tracking is better with the 6 additional points in the metering circle...

Good, but regarding the 6 additional points, isn't that only an advantage over the 20D, and not the 30D? (I could look this up, but I'm lazy).

[SkipD]

Skip, what is your personal preference?? Which cameras do you own/prefer? Let's forget about the technical aspect of it.. Which of these cameras have given you the best results?My personal preference would be a camera that does not yet exist. I'm waiting for a 20 to 30 megapixel 1-series DSLR.

I currently own a 20D. Given enough funding, I would probably have a 1D MkIIN for general use today. Unfortunately, I have too much cash sunk in my current equipment to buy much more and keep my wife.

When I get my 1-series body ("full-frame" or not), I will probably keep the 20D, though, because it will always make sense when going for the long lens shots.

[Phil Light]

Absolutely. It's a killer for portraits & weddings. Skin tone rendition is just amazing. And the larger receptors mean that control of noise is phenominal (not that the 30D isn't a class leader). One proviso; you need good glass (not exclusively 'L' ) to get the most from the FF sensor...

Portraits, weddings, skintones etc. are more the type of thing I'm concerned about. I do have a couple of "Ls" and I am planning to also order the EF 50mm 1.4 in order to get the double rebate offer. I'd like to get more lens than that but again ($$$)...

[pcasciola]

The higher pixel density of the FF sensor will yield higher quality images when cropped than if shot with a cropped sensor.. The FF sensor records more detail than an APS-C sensor..This is simply not true. There is no full frame camera on the market today (including the 1Ds Mk II), that has a higher pixel density than any of Canon's current 1.6x sensors. If you take a 5D image and crop it down to the size of a 1.6x sensor, you are left with only 5MP.

The higher pixel density of the 1.6x sensors is why some people refer to it as a magnification factor. The highest pixel density records the most detail. So, while the crop sensors are recording a smaller FOV than a full frame, they are resolving more detail so in effect, it is almost as if you had a longer lens by virtue of the higher pixel density.

Here's a good comparison. The 5D is not included, but the 5D's pixel density is exactly that of the 1D Mk II. Zoomed out, the same shots seem to favor the 1Ds Mk II, but at 100% crop the 20D has the most detail when using telephone lenses. Page 4 gets into the higher pixel density of the 1.6x over full frame.

http://www.sphoto.com/techinfo/dslrsensors/dslrsensors.htm

[Phil Light]

Don't worry Jeff.. Usually the one's that don't think it's worth it have never owned one! I can tell you a million reasons why I'd take the BMW 760 over the MB S600, but I'm no expert... I don't own either!!!

Right, I don't doubt that what is being said is technically correct, but the proof is in the shot. I guess it's like they(?) say, 5 million 5D owners can't be wrong. ;)

I make my living off of my cameras, and I want the best! I would love the 1Ds, but it's not in the cards for about 6-12 more months!

The 1 series would be awsome, but there's not going to be one in the cards for me for a while either.

The 5D feels better and a little bigger... You can see more through the VF (not a huge deal)... The shutter makes a good bit of difference, especially with slow shutter speeds... Better low-light focusing.. -.5 EV compared to 0 EV..

Want me to go on?

:D Yes, but not really. :D You've been a big help! Thank you.

[Jonathan Consiglio]

I didn't mean the amount of pixels per area... I meant the size of each individual pixel..

[pcasciola]

Larger photsites allow for more dynamic range, but not more detail (resolution). The size of the photosites has nothing to do with the density. Pixel density is the number of photosites over a given area, and the 1.6x sensors are the highest density.

[pcasciola]

I'm definitely not trying to say the 20D is better than a 5D either, just different. The main difference being that for telephoto shots, you get the most detail with the higher pixel density of the cropped sensor. Check the link I posted. There are great real world comparisons there that clearly show the 20D recording the most detail over the exposed area compared to the larger sensor.

[pcasciola]

Sorry I worded that wrong.. But from everything I've read and personnaly seen, the images right out of camera are better from the 5D.. Skin tones are better.. Noise levels are far superior.. Personnaly, I could care less about the wide angle advantage. The biggest thing for me was the noise and skin tone rendition.. The latter not being majo because I shoot RAW and use CS2 and Capture One Pro... So that can be fixed..I'm with you there. That I'm not arguing. It was just the point of the detail. If you are looking for pure reach, the 1.6x does have it's advantages, just like the 5D has it's advantages in the studio or at weddings.

[canonphotog]

Don't fret over the information that's been provided here too much. Look at the images forum members have posted from both the 20D/30D, 1DmkII/n and from the 5D. Compare which please your eye the most.

Then take a stroll to your local camera shop and compare if you can, what you see through the viewfinder on a 20D/30D vs a 5D using the same lens. Ideally a lens you currently have and use for most of your shots.

If they will let you, mount your lens on the 5D and take a shot with your CF card installed. Take the same shot from the same place with your 30D and the same lens.

Spend some time comparing them. Re-read this thread. Compare them again.

At some point, whether or not the "difference" between 1.6cf and FF becomes clear, you should at least be able to make a decision on whether or not the IQ of the 5D is something you want.

Ken

[pcasciola]

You know.. I think I see what you're saying..

If my 20 and 5 both have a 300mm lens and I take the same shot from the same position, after cropping the 5D's subject to the size of the 20D's, the quality of the 20's at that point would be better?? right?

If the 5D had a 480mm of equal quality for the same shot, then the 5D would definitely have better image quality.. Agreed??

I definitely agree with what you're saying. It seemed that people were saying there is no image quality advantage for the 5D over the 20/30... But now I see what y'all meant! I HOPE!!Yeah, I think we're on the same page. I don't mean to say one is better than the other either, just that the 20D's would have more detail (resolution detail that is) when taken from the same position with the same focal length.

I'm also with you on the 1D MkII N. For me, I think it's the perfect combination of crop vs. speed. The 1.3x at 8MP has the same pixel density as the 5D, but enough of a crop factor to be able to do 8.5fps. I'm chomping at the bit to upgrade, but with all the talk of a new version coming out, and with a lot of rumors flying about what it might be, I'm going to try and hold out and see what Canon does.

[chris clements]

If my 20 and 5 both have a 300mm lens and I take the same shot from the same position, after cropping the 5D's subject to the size of the 20D's, the quality of the 20's at that point would be better?? right?

The 20D will contain about 3m more pixels once the framing has been matched in your pc (the center cropped from the 5D image)
Not sure exactly what you mean by the quality being 'better'. There's more to it than just pixel count. As has been said, the larger size of each individual 5D receptor (which equates to LOWER pitch on the sensor, not higher) means wider dynamic range and less noise (bigger receptor= bigger signal generated= less amplification needed).

[20droger]

Right, I don't doubt that what is being said is technically correct, but the proof is in the shot. I guess it's like they(?) say, 5 million 5D owners can't be wrong. ;)
This is the Maginot argument, and is fallacious.

I do believe that 5 million 5D owners are right, but not because there are 5 million of them.

[20droger]

The arguments in this thread mostly overlook two simple facts:

1) The 1Ds MK II, the 5D, the 1D Mk IIN, and the 30D/20D are all excellent cameras. Be proud to own any of them.

2) The 1Ds MK II, the 5D, the 1D Mk IIN, and the 30D/20D are all different cameras. You should get the one that best suits your needs.

The 1Ds MK II is a high resolution full-frame professional studio camera (that's what the "s" means). If you mostly do studio work, this is the camera for you.

The 1D Mk IIN is a full-frame professional sports camera (high shot rate, etc.). If you do sports or other action photography, this is the camera for you.

The 5D is a lower-cost full-frame general-purpose professional camera. If you do varied shooting, or are on a budget, and yet want the features and benefits of a full-frame professional camera, this is the camera for you.

The 30D/20D is an APS-C general-purpose prosumer camera. It lacks certain features found on Canon's professional cameras. If you need the "reach" of an APS-C camera, if your usage is such that you cannot justify the expense of a 5D (or your budget won't stand it), or if you really don't need the complexity of professional features you will rarely or never use, this is the camera for you.

That's why they make chocolate. Not everyone wants (or needs) vanilla.

[kitacanon]

An issue discussed elsewhere but not here is the perspective differences between 1.6x and 1x factor focal length lenses...

a 50mm lens on a 1.6x has the perspective of an 80mm lens on a 1x factor format, a consderation professional portrait photographers must give for the most pleasing portraits...

What I'm describing about the longer the focal length is the larger background relative to the forground which flattens the perspective and facial features of the subject.

[20droger]

An issue discussed elsewhere but not here is the perspective differences between 1.6x and 1x factor focal length lenses...

a 50mm lens on a 1.6x has the perspective of an 85mm lens on a 1x factor format, a consderation professional portrait photographers must give for the most pleasing portraits...

What I'm describing about the longer the focal length is the larger background relative to the forground which flattens the perspective and facial features of the subject.
What you are calling "perspective" is actually angle of view, or AoV.

A 50mm full-frame lens on a 1.6× camera has the AoV of an 80mm (not 85mm) lens on a 1.0× camera (1.6 × 50 = 80).

"Perspective" is the apparent relationship between foreground and background in a picture. The perspective of a 50mm lens remains the same, regardless of the camera upon which it is used. That is, sticking a 50mm lens on a 1.6× camera does not magically make it an 80mm lens. It remains 50mm at all times.

Try it yourself.

Frame a face shot with an 80mm lens on a 1.0× camera. Then frame the same face the same way with a 50mm lens on a 1.6× camera. Compare the two and you will see that the two faces are subtly different.

Now, take a face shot from a specific position with a 50mm lens on a 1.0× camera. Then take the same face shot from the same position with the 50mm lens on a 1.6× camera. Crop the 1.0× print so the faces are the same size. The two faces will have the same perspective.

[SkipD]

An issue discussed elsewhere but not here is the perspective differences between 1.6x and 1x factor focal length lenses...

a 50mm lens on a 1.6x has the perspective of an 80mm lens on a 1x factor format, a consderation professional portrait photographers must give for the most pleasing portraits...

What I'm describing about the longer the focal length is the larger background relative to the forground which flattens the perspective and facial features of the subject.
What you are calling "perspective" is actually angle of view, or AoV.

A 50mm full-frame lens on a 1.6× camera has the AoV of an 80mm (not 85mm) lens on a 1.0× camera (1.6 × 50 = 80).

"Perspective" is the apparent relationship between foreground and background in a picture. The perspective of a 50mm lens remains the same, regardless of the camera upon which it is used. That is, sticking a 50mm lens on a 1.6× camera does not magically make it an 80mm lens. It remains 50mm at all times.

Try it yourself.

Frame a face shot with an 80mm lens on a 1.0× camera. Then frame the same face the same way with a 50mm lens on a 1.6× camera. Compare the two and you will see that the two faces are subtly different.

Now, take a face shot from a specific position with a 50mm lens on a 1.0× camera. Then take the same face shot from the same position with the 50mm lens on a 1.6× camera. Crop the 1.0× print so the faces are the same size. The two faces will have the same perspective.Fellas, both of you are somewhat misinformed about perspective.

The focal length of a lens does not have any perspective characteristic tied to it in any way.

Perspective is purely and totally a function of the distance between the subject and the viewer (or the camera). You can take a series of photos of a subject from the same distance with many different focal lengths and then crop all the images to show the same amount of the subject. You will then find that the perspective of all the images is absolutely identical.

Of course, image quality throughout the test series will be different, because of the different amount of enlargement of the cropped images.

The statement 'a 50mm lens on a 1.6x has the perspective of an 80mm lens on a 1x factor format' is close to the truth, but only because images from a 20D with a 50mm lens on it and a 5D with an 80mm lens on it, with both photos taken from the same distance to the subject will have the same amount of the subject in the image. The perspective is still, however, a function of the distance between the camera and subject. The two images, taken from the same position relative to the subject will have identical perspective.

Choice of focal length should be made after choosing the distance between the camera's position and the subject's position in order to control the perspective of the image you wish to create. I could go into this at length, because it really should be part of Photography 101. However, unless asked I won't repeat it all here. There are threads that discuss this issue elsewhere in the forums.

Perspective in an image can be changed with view cameras that allow changing the position of the lens relative to the film plane in three dimensions. There are some lenses for SLR cameras that allow some of these adjustments.

[Phil Light]

***THREAD HIJACK NOTICE***

I just ordered my 5D - I'm already watching for UPS! :D

[chris clements]

would it be better to shoot with the 20D, or with the 5D and have to crop...

No absolute answer - in this scenario the 20D pic would have more pixels, but the 5D's pixels would be 'better' (less noise, greater dynamic range).

Anyway, this is a laboratory rather than Real World exercise. These 2 bodies are different tools for different tasks. No one should consider moving to the 5D if they're normally shooting at the long end of their big zoom on their 20/30D, unless they can afford the $$$$$ to buy new lenses and have the muscle to carry around the heavier glass.

If in the real world you find youself constantly having to crop down to the middle of your 5D image because you can't frame tight enough, then you shouldn't have switched horses :)

[kitacanon]

Now, take a face shot from a specific position with a 50mm lens on a 1.0× camera. Then take the same face shot from the same position with the 50mm lens on a 1.6× camera. Crop the 1.0× print so the faces are the same size. The two faces will have the same perspective.

You're right but backwards comparibility-wise...in that you can only make that crop if you're using the FF model...and you're stuck if you only have the 1.6x formfactor bod...

still...the issue is that at the same distance the relative size of the background is the same for a 1x@80 (1x@50) as 1.6x@50...my (1.6x@80...my) point simply being that 1.6x form-factor users must take into account the perspectives or AoV difference to take portraits with 50-70mm lenses if those portaits are to be taken at the recommended focal lengths of 80-105mm in the 1x form factor...

as a side note...in making the comparison myself on my 35mm Nikon I was STUNNED at the beauty of the full frame viewfinder when compared with the D series Canons...and can understand why people shoot with the 5D...if only it didn't cost SOOOOOOooooo much.

[Phil Light]

I do wedding, private parties and portraits, so it's pointless to me anyway!! I guess I just got on a roll!

Jeff, you will be extremely satisfied! Trust me! The wait for the UPS is the best and worst part! You just got yourself a fine camera.. enjoy it, and let us know what YOU think!

Jonathan, thank you very much for your help. I'm sure I will have a lot to say (and ask) after I get the chance to break it in a little. I downloaded the manual and have been reading it for the last two hours. The first thing to strike me is that at least the first hundred or so pages so far are almost word for word identical with the 30D manual. I'm amazed at how similar these models are.