Need Help Determining Which Body - 5DM2, 5DM3 (limited budget), 6D or 7D

Hi Katie,

I'm going to copy/paste a bit from an earlier post elsewhere on the forum.

If I'm reading your needs correctly, the XSi has been working out while shooting in many of the scenarios you find yourself in. You're problems seem to be noise at higher sensitivities and AF in more demanding situations.

I have a friend who owns both a 5D Mark II and a 7D, and I've been looking for my first DSLR. Undeniably, both are fine cameras, as I've discovered. Both will probably be worlds better in the high ISO department than the XSi. Between these two cameras, the 7D does have the autofocus advantage, hands down, and I doubt there would be anyone who would challenge that statement. I hear the 5D Mark III does much better in the AF department, and the 6D - from the preliminary reports I'm seeing - is roughly the same as the 5D Mark II. The 6D also seems to have roughly the same image quality as the other full-frame cameras (you'd really have to be nit-picky to find differences), which all seem to be a smidge better than the 7D.

One thing worth considering is an APS-C camera does help somewhat for a cash-strapped telephoto photographer. With the 1.6x crop factor, your 70-200mm lens is a 112-320mm lens. On a full-frame camera, well, a 70-200mm lens is a 70-200mm lens. To get that range back, you'll probably have to sell it for maybe a 70-300mm (which will have a smaller aperture, and that obviously won't help in the noise department). In a portrait scenario, the 24-70mm becomes a 38.4-112mm. This is still fairly useful normal-to-medium-telephoto focal range, but you may have to consider the purchase of a wider angle lens for larger group photos (perhaps a 10-22mm EF-S, which roughly works out to be a 16-35mm).

The other thing to consider is my friend has both a full-frame and a fast APS-C camera, and he uses both of them for different purposes on the same assignment. It would appear, even if you have serious cash on hand, there is no one perfect camera that handles everything well and likely there will have to be a compromise made somewhere. I will probably continue to carry around my Panasonic GX1 after I buy a DSLR because it's better for street photography. A DSLR will scare off most subjects, bring unwanted attention to the photographer, and it doesn't disappear into a coat pocket or a bag very well.

If you can, get your hands on these products and try them out yourself. Bring your lens collection to the store, put them on these cameras, and take a few shots. I'm sure you'll know quite soon afterward which one is for you.

Best Regards