I currently have a 5D and my new 7D. Ever since I got the 7D, I haven't touched the 5D. Problem is my lenses are tailored to FF. I LOVE the 7D and all the features. It is sheer pleasure to use.
My plan was to use the 7D as more of a general-purpose camera and take the 5D when I need 2 bodies (i.e. weddings).
Has anyone done a comparison of 5D to 7D in terms of IQ and Noise? I've seen one review that compares 5D2 to 7D but in real life I haven't seen vast differences.
Also, what do you guys think of switching up my lenses:
24-105 -> 15-85
12-24 -> 8-16 or 11-16
And maybe:
50 1.4 -> 30 1.4
The advantages I see are the larger range on the 15-85 (136mm eq.), and f/2.8 on the Tokina.
In a wedding situation I would use the 15-85 on the 7D and 70-300 on the 5D, or 50 on the 5D and 100 macro on the 7D.
Decisions, decisions....

