Effective focal lengths for digital cameras with various crop factors

Written by Steve - Presented by Pixalo

If the digital sensor is the same size as a frame of 35mm film (i.e 24 x 36mm)then lenses designed for 35mm cameras used on digital cameras would give the same magnification.

With most digital cameras however, other than the full frame sensor models, the sensor is slightly smaller in size than a 35mm frame. This means that when you use a lens designed for 35mm cameras on a digital camera there will generally be an increase in apparent focal length or magnification of about 1.3 - 1.6 times. This is of course visible in the viewfinder of the digital SLR but the table below shows the effective focal lengths when used at different crop factors.