I have put some thought into this and I think I understand where the fellow is coming from. I admit he is thinking about things in.. a new way.
Consider a field of view for the final image that frames a Volkswagen with proper emissions control.
1 > At 28mm on a FF, we use crop mode to frame the VW. This gives us an equivalent field of view = 42mm.
2 > At 42mm on a FF, we do not use crop mode to frame the VW. But, we see the same environmentally friendly vehicle as with 28mm+crop.
Alright, the argument is that there is more detail because longer focal length is used in scenario 2 above. Maybe...
Really, I think there is more detail when the longer focal length is used and it is for this reason: In scenario 1, the FF sensor is cropped digitally. The wider view with the 28mm lens is cropped by disregarding portions of the FF sensor and we end up with the VW front and center.. In scenario 2, all the FF sensor is used. A crop is still performed but it is done optically. The wider field of view with the 28mm lens is reduced by mounting a 42mm lens... VW front and center.
So, it could be argued the 42mm lens, being longer, provides more detail. However, I think the better argument is that the 42mm lens performs an optical crop versus the digital crop made when the 28mm lens. We all know cropping with lens is better than cropping digitally...
Originally posted by clackers Oh, thought you were leaving!
Here we go:
"you are getting more details because of the longer focal length."
Do you remember writing that? ☺