Many digital cameras have zoom lenses whose numbers might look funny if you're used to the focal length numbers on film lenses or digital cameras with sensors the size of 35mm film. For example, a 5MP Kodak EasyShare CX 7530 camera has a lens that measures 5.6-16.8mm, which is equivalent to a 35mm film lens that's 34-102mm. The effective length of the lens depends on the physical dimensions of the camera's sensor -- the area on which the light coming through the lens is spread. A camera with a sensor measuring 14.8mm x 22.2mm (rather than 35mm film's 24mm x 36mm) has a conversion factor of about 1:6.

Some companies, including Kodak, have started to put the film equivalent on the lens itself to lessen confusion about the in-fact value.