APS-C or full frame

[Paul McAdams]

After shooting my Canon 20D for many years, I'm planning on upgrading sometime this year, and I'm considering going full frame, as in a Canon 6D or 7D. I want to make sure my understanding about APS-C has been correct all these years... and that is if I cropped my full frame photograph to match the image that an APS-C would have given me, I have basically the same thing, so going full frame really does not lose any advantage or features of a cropped frame sensor.... is that correct ? That said, is there any advantage of a cropped frame over full frame?

Anyone use either the 6D or 7D that would recommend one over the other ? Its either that or a cropped frame 70D...

Debating....

[DickLudwig]

You have to add one thing to your statement and that is pixels on the subject. If you take an image with a 7D and take the same image with a 6D from the same spot, with the same lens and then you crop the 6D image to the same image that was captured with the 7D; you will have far more pixels in your 7D image then you will have in your 6D image.

[David Stephens]

You're posting in a bird photography forum, so I assume that bird photography is important to you. If so, I'd say that AF function is more important than pixel-pitch, by a mile. The 7D, which isn't full-frame BTW, has high pixel density and is a Canon champ when it comes to pixels on a subject, but it isn't even close to the 1D X at locking onto a moving subject with a super-telephoto lens, particularly with teleconverters attached. The 1D MkIV is also better than the 7D, as is the 5D MkIII. I own the 7D and the 5D MkIII and I've had a 1D X on trial for an extended period. The 1D X blows away the 7D and, by less margin, the 5D MkIII, when used with an EF 500mm f/4L IS II, either with or without the 1.4x and 2.0x TC-III. BTW, the 6D doesn't even try to compete in the AF area.

[Paul McAdams]

Sorry, my mistake, I cruised the Canon site and assume xD vs x0D was full frame vs crop, so I lumped the 6D and 7D in the same category.

The 1D-X and 5D MkIII are out of my budget. I have a lot already invested in L glass, but I just can't do 4k+ on a body. My original question was if I cropped a full frame image to match what I would get with a cropped frame, would I have the identical image, and after some consideration, I think the answer is no since cutting a full frame down would not give the higher density pixel count the APS-C would, assuming both weigh in at the same, e.g., 20M, at their original size. That said, and yes birding is one of my fav subjects, I'm now leaning back towards another cropped frame. So assuming I just knocked out their full frame line up, it looks like its 7D vs 70D judging from their latest product line....

[Ian Cassell]

Paul, you might consider waiting a bit if you're not in a hurry (which, considering you're still using a 20D, I assume you are not). Although still only rumors, there is very strong belief that there will be a replacement for the 7D this year - possibly in the third quarter. The body was released in 2009 and is long overdue for updating. I love my 7D (which I bought when it was first released to replace my 30D), but the AF and high ISO performance could certainly use improvement. The technology is there - the 5D3 and 1DX both have super AF and high ISO. I want to keep the crop sensor and, anyway, don't have the money for a 1DX. I'm waiting (not so) patiently for a bit rather than sinking my cash in a 5D3.

Some expect the 7D2 prototypes to emerge at the Olympics in Sochi -- keep your eyes peeled.

[Paul McAdams]

I just googled the rumors on the 7DMII (high-end APS-C). Thanks very much for the info, I've waited this long, I can wait awhile longer :w3