I post too Much on Here!!
- Jul 21, 2010
No doubt. But there are several relevant factors besides sensor size and "reach". When I had a 7D then bought a 5DII, I continued using the 7D for BIF because of the better AF and higher frame rate. At the high ISOs needed for shutter speed early/late in the day, FF trumps crop. Also, a 7DII has no 'reach advantage' over a 5Ds.I may not have been as clear as I hoped above. Some of those I know who use long focal length lenses with crop bodies also own FF bodies, but they don't tend to use the FF bodies when using the long lenses for BIF.