Just a stupid question comparing Canon 40D, 50D, 7D (1 Viewer)

Hello all,

I currently have a Canon 40D...lovely camera. As far as "apparent reach" is concerned I am curious what the extra pixels of a 50D or 7D would yield when compared to a 40D. Basically, I'm wondering if there are any comparisons anyone has done with any of these cameras side by side with the same lens to show how much more cropping is acceptable with the higher end camera.

I could've sworn I have seen a comparison years ago with a flycatcher species, but I cannot find that.

Hope this all makes sense!

The first four images in this album show the "reach" advantage of the 50D vs 40D vs 30D vs 1D3. The fifth photo shows the whole frame as seen by the 50D. You can figure pretty easily the extra reach the 7D might offer, being 9% larger than the 50D image on a linear scale.

http://picasaweb.google.com/EezyTiger/Reach

Be aware that you can only maximise the reach advantage if you can shoot with perfect focus, no shake, no blur, no pixel level noise, sharp glass. That means that for shooting BIF, especially in anything less than strong light, the reach advantage will probably be eroded quite quickly.

If your shooting is not perfect (soft, blurry, shakey, noisey) then potentially all you will get from smaller pixels is a higher visible softness, and/or noise, when viewing at 100%, requiring you to view at less than 100% for acceptable IQ and thus negating the reach advantage. In my experience, shooting with my 100-400 zoom, I get no more reach for BIF from my 7D compared to my 1D3 as the pixel level quality is not there. That is not a fault of the camera. That is a practical constraint of the lens and my own limited photographic skills.

However, put a sharp prime (e.g. 500/4L) on a 7D and shoot from a tripod in good light at low ISO and the 7D should eat the competition for breakfast.

Although I've said this before, it's also worth repeating that the harder you crop into a file the fewer photons you retain for your final image and you can only stretch those photons so far before the cracks show. From some of the comments I've seen around on the internet I really think people sometimes expect (far) too much. A 100% crop from a 7D is a significantly larger magnification of the image (33% larger) than a 100% crop from a 40D. That should not be overlooked. If at the pixel level the image looks worse, that should not come as a surprise. Even viewing at 33% is a pretty large size image on most monitors. 100% is verging on ridiculous - for viewing from 12-18" away. Forget about pixels for a moment and just consider enlargement factors to appreciate what might be reasonable.

Depends what you mean by "apparent reach". They are all 1.6 croppers so effective reach (FOV) is the same. I have only had the 7D for a short while but do not think you can crop a lot heavier than with the 40D (I have often used 100% crops from the 40D for web images - not sure that this will be so with the 7D). What you do get with the 7D is more pixels on the bird, so a bit more fine detail.