Originally posted by BrianR If you mount a FF lens on an APS-C body, every time you click the shutter you are murdering photons by sending them screaming into the side of the mirror box instead of letting them meet their destiny by striking your sensor or film.
I believe we finally found the source of dark matter!
The next Nobel prize will go to PentaxForums for sure.
So it does seem rather philosophical after all. In the end you pick the tool for the results you want.
At first crop factor was declared to make the digital move easier for analog users. Whereas someone purely digital like me sees it more like extra focal length for less money. Not because manufacturers advertise it as such, but because I don't have any comparison to the old age and interpret it that way.