I believe that this has been discussed previously, but I couldn't locate the thread(s). I am going to Alaska this summer to photograph the brown bears at Lake Clark and I will be shooting with a 1Dx. I will have a 7D as a second body. If I were to capture an image of the same bear from the same distance with each body & 500 mm lens, then crop the full frame image so that the bear is the same size as in the 7D image - or crop both images so that the bear is the same size - will the "quality" of the bear image be essentially the same when printed? I would like to make large prints, e.g., 16 X 24. Thanks for any assistance with this.

The 1DX image cropped to the same image content as a 1.6x CF image would have 3240 x 2160 pixels. The 7D image would have its full 5230 x 3479 pixels. The question then becomes, which camera has "better" pixels? Based on my personal experience with both cameras, the 1DX has much better per-pixel IQ. Does this perceived difference in IQ quality make up for the large difference in pixels-per-bear? I don't know.

P.S. I'd use a 1.4x Extender III with the 1DX, and also bring a 1DIV.

It's the pixel density that matters (as illustrated in jcolwell's example).

The 7D and 60D have the highest pixel density in any Canon camera, that's why many are waiting for a 7DII with 24mp or so which will give us even higher pixel density!

howard wrote:

The 7D and 60D have the highest pixel density in any Canon camera,

You mean apart from the 550D, 600D and 650D which have the same sensor?

I've posted this before. The cat stayed in the same place for all three shots with the 500mm lens all I did was change camera bodies. The have nothing to do with final image quality it's just showing different crops.

rprouty wrote:
I've posted this before. The cat stayed in the same place for all three shots with the 500mm lens all I did was change camera bodies. The have nothing to do with final image quality it's just showing different crops.


The OP already knows about crop factors and is not inquiring about any of the three bodies you mention.

Richard, since you will be investing all that money going to Alaska, why don't you carry out that test yourself before going?

Imagemaster wrote:
rprouty wrote:
I've posted this before. The cat stayed in the same place for all three shots with the 500mm lens all I did was change camera bodies. The have nothing to do with final image quality it's just showing different crops.


The OP already knows about crop factors and is not inquiring about any of the three bodies you mention.

It seems you are "always" looking for something negative to say?
I thought it might be of some help to some that may have questions about crop factors.
Do we need to run all posts and replies by you before posting them?

howard wrote:
It's the pixel density that matters (as illustrated in jcolwell's example).

The 7D and 60D have the highest pixel density in any Canon camera, that's why many are waiting for a 7DII with 24mp or so which will give us even higher pixel density!

Doesn't the G10 have this honour?

Imagemaster wrote:
Richard, since you will be investing all that money going to Alaska, why don't you carry out that test yourself before going?

+1. This makes the most sense. Acceptable differences between sensor sizes versus the use of a 1.4 or 2X TC are VERY subjective. For example, I much prefer the output from my 1DMK3 versus a 7D (even though the 7D clearly has a pixel density advantage). So much so, in fact, that I sold the 7D. Others would strongly disagree with this.

So when you ask a highly subjective question, and there is a big trip ahead of you, it makes more sense IMO to avail yourself of lensrentals.com (if you don't already have all the equipment) and test the equipment for yourself. Sounds like you have time, so do the test yourself and get an answer that is useful for YOU.

Richard, what would be more relevant is to crop all the images the same size. For example, the same size as the 50D shot. That is what happens in focal length challenged situations. One needs or desires a tight crop so the images from the 5DII and 1D3 would get cropped. How does that compare to a higher pixel density sensor? The images posted do not address the OP's question:

"If I were to capture an image of the same bear from the same distance with each body & 500 mm lens, then crop the full frame image so that the bear is the same size as in the 7D image - or crop both images so that the bear is the same size - will the "quality" of the bear image be essentially the same when printed?"

Since these shots are all varying FOV, nothing can be directly compared.

galenapass wrote:
... For example, I much prefer the output from my 1DMK3 versus a 7D (even though the 7D clearly has a pixel density advantage). So much so, in fact, that I sold the 7D. Others would strongly disagree with this.

I agree. I sold both my 7D and 1DIII to get a 1DIV.

Using Jim's math I'd crop an existing 1Dx photo to his suggested size (3240 x 2160) & then crop it into 1/6 sections & print one or 2 of the sections as 8 X 8's. This would give a pretty good idea of the finished look IF you could use the shot without cropping deeper into it. I've done this many times before to analyze how something might look when enlarged more than I can print at home.

I recearched this extensively, did my own testing with a 7d, 1d4, 5d2, 5d3, using extenders, various ISO's and searched for other tests.
1. Under LAB CONDITIONS if you are focal length limited (have to crop to the size of apsc or smaller, for the snesors of same generation, you are always better off with higher pixel density (obviously not crop factor, since 5d2 has same pixel density as the 20D even though 20d has 1.6x crop factor. its all about pixel density).
a: you wont be shooting in a lab
b: you are talking about densor designs of different generation, so 1dx may have better design
c: as you move up high iso, the gap becomes less, but the larger pixel density for the same final output size, will always do at least as well, many times better in detail
2: again for sensors of same generation (5d2 and 60D say) you are better off using they higher pixel density than a converter. the advantage here is slight. Note that those two will give you same pixels on duck (5d2+1.4x, is about same pixel on duck at 60d). of course, there is also great advantage to not having to deal with slower af of an extender.
3: In real life, many issues come in to the picture.
first, above and beyond everything else is technique. with long lens, high pixel density and cropping, you are looking at very fast shutter speeds and excellent technique to have pixel level sharpness anyway. if you cant achieve that, a slightly blurry image on 1dx, would not resolve any better on a 7d.
second, if you have to crop, I find having the viewfinder magnification of a crop sensor and framing properly, is helpful and a plus
third, all cameras are no created equaly. autofocus speed, accuracy, buffer size, general handling, can make a big difference in getting the shot, and getting a sharp shot.
fourth, low quality consumer lens is less able to take advantage of higher pixel density (advantage does not entirely go away, but becomes significantly less) so a simga 150-500 os at 500mm for example, will have far less advantage on a 7d over a 1dx, compared to say the 500 f4L lens.
Hope someone finds this helpful

I think point C is really important:

"c: as you move up high iso, the gap becomes less, but the larger pixel density for the same final output size, will always do at least as well, many times better in detail"

I do a lot of shooting in low light conditions and this is an important point to consider when that is the case.

Thanks to all for the input, it is very helpful. I will do a side by side comparison. I was seeking input from FM Forum members because I don't have the technical knowledge that so many other forum members have, and I find those technical insights very valuable. Thanks again.

rcm123 wrote:
I believe that this has been discussed previously, but I couldn't locate the thread(s). I am going to Alaska this summer to photograph the brown bears at Lake Clark and I will be shooting with a 1Dx. I will have a 7D as a second body. If I were to capture an image of the same bear from the same distance with each body & 500 mm lens, then crop the full frame image so that the bear is the same size as in the 7D image - or crop both images so that the bear is the same size - will the "quality" of the bear image be essentially the same when printed? I would like to make large prints, e.g., 16 X 24. Thanks for any assistance with this.

If you use the same focal length and both cameras have the same photosite density per square millimeter, the IQ would be essentially equal. If you use the same focal length and the density per square millimeter is different, the image with the higher photosite density has a greater potential to record detail as long as the resolution of the image is not limited by other factors such as lens quality or camera instability.

And... you should be able to make excellent 16" x 24" prints from well-shot originals from either camera.

Dan

Kevindar, thanks for the explanation. Could you expand on the tradeoff of "5d2+1.4x, is about same pixel on duck at 60d" if you've experimented with this? I have both 5D2 and 7D to use with my 100-400. I find the images with the 5D2 are superior to those from the 7D when not reach limited. So the question, hopefully relevant to the OP, is whether using a 1.4x and an extra stop of ISO on a 1DX or 5D3 will yield a better or equivalent image quality to using a straight 7D? I'm considering replacing my 7D with a 5D3 and using a 1.4x to achieve equivalent pixels per duck when necessary. Thanks.

gdanmitchell wrote:
If you use the same focal length and both cameras have the same photosite density per square millimeter, the IQ would be essentially equal.

Not sure what you are saying here, if both cameras have the same photo-site density don't they essentially have the same sensor? 7D v 60D?

Jeff Nolten wrote:
gdanmitchell wrote:
If you use the same focal length and both cameras have the same photosite density per square millimeter, the IQ would be essentially equal.

Not sure what you are saying here, if both cameras have the same photo-site density don't they essentially have the same sensor? 7D v 60D?

I wrote about photosite density per square millimeter, sometimes described as "pixel pitch." The two cameras might have the same number of photo sites but if you crop a bunch of them out to retain only an APS-C sized section of the full frame image, you will obviously end up with fewer pixels in the resulting image. If you print very large, that could make a difference.

Dan