Crop factors, not again...

[chriso]

OK, here's an interesting thought...

Comparing the 12 or so megapixels of the Canon 5D and the Nikon D2X - where we have a full-frame sensor, and a 1.5 crop factor sensor.

At equal distance from the subject, using lenses of the same focal length, the 5D will see a bigger picture than the D2X due to the crop factor on the D2X. Thus, the 5D has to fit more information (not really more information, but describing it this way makes it easier to follow) into 12MP than the D2X. When the images from the 5D and the D2X are directly compared, doesn't matter whether it is on a computer screen or printed (as long as the prints are of the same size, and both images remain at their native, out of camera resolution of approx. 4300 x 2900 pixels), then the D2X image wil APPEAR to have 'zoomed' by the crop factor.

Am I plain stooopid, or is there some twisted form of logic and truth to the marketing hype after all ?

[markthomas]

In theory you are correct, but in practice no. When I take a pic I frame it the way I want to. If you gave me two cameras (a 1.5 crop and a full frame) and you asked me to take a pic of a bowl of fruit with a 100mm lens the pics would look almost identical because I frame the same in the viewfinder and would just stand further back for the crop camera.

Where you do have an advantage is when you can't get close (birds and animals) and the 1.5 will "crop off" some of the surrounding area.

Make sense?

[Daryn Varney]

. If you gave me two cameras (a 1.5 crop and a full frame) and you asked me to take a pic of a bowl of fruit with a 100mm lens the pics would look almost identical because I frame the same in the viewfinder and would just stand further back for the crop camera.

Thanks for finally putting it plainly and hopefully no one else will get confused with this again.As it popped up in the last post with this I sort of began to wish this crop issue was never brought up originally and would never be brought up again either.

[chriso]

Makes sense, yes Mark, but not my point.

I tried to illustrate a possible explanation for why lots of people still believe that crop factor means extra (free) lense power. Heck, I can go to most any photographic shop, and have at least one of the sales staff try and convince me cropping means longer focal length. Thats specifically why I used the terms equal distance, equal focal length, equal pixel dimensions.

[markthomas]

The point you are making is true (as stated in my second paragraph), it does actually mean extra (free) lens power. The focal length is effectively lengthened. If all the pixels were equal a crop factor camera would be a better bet for telephoto shots. The ff obviously wins on the wide angle end though.

The camera sales staff are correct, but we can't test the end result quality because ff and crop cameras of the same mp will have different pixel sizes/pitches and therefore quality will differ.

[Ernst]

For me it was very simple: I wanted (high-res) digital. I also still wanted to use all of my favourite lenses, the same way I did with film. FF was non-negotiable for me. The wait was worth it and I did not spend a small fortune on new lenses. That's why I went for the FF EOS 5D.

Just a thought: the pixel pitch of the sensors of the EOS1DMk11(N) and the 5D are identical. For the same lens, same distance from subject, the 1D... would have a 30% tighter cropped frame (1.3x crop factor). However, the 5D has 50% more pixels (8MP x 1.5 = 12MP), so for the same quality final print size output, the 5D can crop out 50% of the frame and then have a 20% tighter cropped shot than the 1D... at the same quality. Or am I missing something here?