Originally posted by Marc Langille Very good points Marc! Now the OP's question is evolving into additional comments and answers, so it's beginning to go beyond the focal length issue by including pixel densities of the sensor on APS-C, etc.
True enough. But my goal was to try to cut through all that and get back to the main point that is relevant to most people who are not up on all the science and so forth and are still having a hard time wrapping their brains around the basic idea of what the crop factor is. For 99% of photographers, FOV is the only attribute of focal length that they care about, even if they don't realize up front what FOV actually is. So I'm just trying to put it into the simplest possible terms: it is how big your subject appears *on the print*. Details of viewfinder magnification, sensor resolution, lens resolution, etc just don't really matter to most people when trying to get the basic idea of what a crop factor is about, although of course it might become relevant when one is looking for ways to squeeze every last drop of image quality out of their gear.
Quote: I agree with most of your points and bottom line is that I'll stand by my post. The lenses' focal length remains unchanged regardless of sensor size and the object is no closer.
Absolutely agreed.