« on: June 28, 2014, 11:11:34 PM »
Firstly - nice shots...
One issue you might find doing macro with the FF is the shorter focal length. I know insect photographers often prefer telephoto macro, primarily to avoid scaring off their subjects.
I do a lot of macro with APS-C cams, the 100 f/2.8 non-L and MP-E 65mm but I also bought the EF-S 60mm about a year ago mainly for larger subjects (especially when working on a copy stand) but also as a backup macro lens (I did have my 100 fail once, blowing the motor). I'm certainly happy with the EF-S 60 but I was a bit shocked at how short the working distance is when approaching 1:1.
Hence you may find the 70D better to work with, but if you wanted to use the 6D more then adding a telephoto macro lens will be beneficial. The Canon is very expensive but Tamron and Sigma also make decent versions.
Yes crop cams have a greater dof and FFs better IQ but I don't see this as the most important issue really for `normal' macro shooting. If you look at the photozone reviews for example about the highest rez they get from a Canon crop - using the optimal aperture - is just under 2700 (Sigma 35A), whereas the 100L exceeds this across the entire frame on FF even at F16. Where crops do help is at very high magnifications, when dof is extremely thin. I photograph a lot of stuff under 23mm, more to the point a lot of stuff under 4.6mm (minimum fov with the MP-E on APS-C) so crop is a no-brainer for me. Crop iq is still very good. Most macro shooting is at low ISO.
I find the flip screen of the 70D to be very helpful and versatile and I love being able to turn the screen inward when the camera is not in use, so it is less likely to get scratched during transport, etc.
Overall getting a focal length that you are comfortable is what I see as the main issue. The quality of macro shots has more to do with composition, lighting, stability, technique, aperture choice, dedication, effort, etc than with sensor size.