View Full Version : Digital SLR focal legenth multiplier effect on image compression


John DeLuca
October 3rd, 2004, 08:23 PM
We all know about the 1.5X focal legenth multiplier factor on most current digital SLR's, where your 50mm effectively becomes a 75mm. Of course what is actually happening is your 50mm lens is still projecting the same image, the smaller chip size in the digital SLR is just cropping the image.

What I am trying to understand is if you get the same amout of image scene compresssion as a lens of the higher focal legenth equivalent. Is my 85mm lens on my Nikon digi SLR's compressing the scene as much as a 127mm focal legenth lens would on a film body, or is it still compressing the scene as much as an 85mm would on a 35mm, and only cropping the image.

John

Jeff Donald
October 3rd, 2004, 08:36 PM
Perspective only changes when you change the position of the camera in relationship to your subject. Changing the focal length of the lens, either by changing lenses or zooming, does not change perspective.