OK, I’ve had about enough of the misinformation about crop factor! I’ve read a number of articles saying that the crop factor of a digital sensor increases your telephoto’s ‘range’ by 1.5x and touts that as an advantage of having a smaller sensor … increased telephoto range!
The only thing that a smaller sensor does is reduce the area of the image capture, giving it and effective CROP factor, not a zoom factor! So, when I use a 500mm lens on a full sensor, I get the coverage of a 500mm lens. When I use it on a APS-C sensor, I get the COVERAGE of a 750mm, with the magnification of a 500mm lens!
In the above image, the whole image represents what might be seen on a full frame camera utilizing a 36mm x 24mm image sensor; inside of the black lines would be what you would capture using an APS-C sensor, which is about 75% the size of full frame. There is no magnification, only a crop.
Below is a life sized representation of a full frame sensor (white) and an APS-C sensor (black). (36mm x 24mm @72 dpi = life sized)
BTW, the top image was taken on my D2X, which has an APS-C sensor, not full frame. I just placed the black box at the 75% points. The only full frame digital cameras that I know of are: Canon EOS 5D ($3600), and EOS-1Ds Mark II ($7,000). Mind you most manufacturers stick with the smaller sensor because costs a lot less and results in a somewhat smaller camera.
OK, now I can get down off of my soapbox! I’m feeling better.