making a case for that crop body camera

[RMC33]

I see a lot of people complain about the AF on the 7d for subject in motion. Is it erratic un-predticable or just motion in general?

I do a lot of skiing/snowboarding work with my 7D and 5d3 and have no issue on the AF with either through a 200 f/2 and 400 f/2.8 mk II. Most of the motion I am capturing is smooth and fluid which lends to the ease of capture. I assume that the complaints come from BIF or such?

[neuroanatomist]

I haven't done a test, but wouldn't I have a shallower DOF if I used my 5DII with my 100mm macro with the same framing- ie: I'd have to be significantly closer with the 5D?

Yes, at the same f/stop, the DoF would be shallower with FF.   But when you consider diffraction (you can stop down the lens more on the FF sensor before diffraction costs you sharpness), there's no 'APS-C gives deeper DoF' benefit.  Both formats can achieve the same deepest DoF for a given amount of diffraction, but the FF can achieve shallower DoF if desired. Just another benefit to the amazing FF sensor. 

[pdirestajr]

I'm just joking mostly. FF images are beautiful. I would have purchased the 5DIII over the 7D if that was the offering I had at the time. I just wish it had a pop up flash then!

I might have to write an open letter to Canon threatening to switch to Nikon! That will surely do it.

[moreorless]

If you need a larger image in a landscape scenario...photomerge is a no-brainer, just use a longer lens.

I see this arguement alot but honiest to me the majority of merged pics look like exactly that, merged pics with fairly uninteresting composition.

[Plamen]

If anything, the smaller sensor probably helps me with a little more DOF.

Smaller sensors do not have more DOF. You get the same DOF with equivalent settings; and if you push it too far, you get a very soft image due to diffraction anyway.

Not that I disagree that the 7D can be better for what you are doing.

I haven't done a test, but wouldn't I have a shallower DOF if I used my 5DII with my 100mm macro with the same framing- ie: I'd have to be significantly closer with the 5D?

I always thought focus distance was part of the factor in DOF. Again, I'm not a lab tester of this stuff, I was only assuming another benefit to the amazing APS-C sensor

My remark did not include changing distance. After all, you could use the EF-S 60 macro, which is excellent.

[AlanF]

The 7D came out in 2009. It is still a remarkably good camera. The fair comparison with FF as far as crop sensors go would be a 7D II vs 1D X or 5D III as they have 3 year newer technology in focussing and sensor. A 7D II with the focussing of the 1D X/5D III and an improved sensor would be an incredible beast.

[comsense]

I haven't done a test, but wouldn't I have a shallower DOF if I used my 5DII with my 100mm macro with the same framing- ie: I'd have to be significantly closer with the 5D?

Yes, at the same f/stop, the DoF would be shallower with FF.   But when you consider diffraction (you can stop down the lens more on the FF sensor before diffraction costs you sharpness), there's no 'APS-C gives deeper DoF' benefit.  Both formats can achieve the same deepest DoF for a given amount of diffraction, but the FF can achieve shallower DoF if desired. Just another benefit to the amazing FF sensor. 

+1 In addition, for the same DoF, infinity background blur (dependent on physical size of entrance pupil in an imaging setup) would be more with FF format as it allows larger entrance pupil. Could be little to significant depending on other parameter. In simple words, it can provide better subject isolation with right setup and object distance.