You can use the lens aperture to control the amount of light reaching the film as well as the picture's depth of field.
Depth of field refers to the apparent sharpness within the picture field, from near to far.
This will enable you to use higher shutter speeds. The maximum aperture of a lens makes a difference when taking indoor shots or twilight pictures in available light. Note that some Nikkor lenses of the same focal length have different maximum apertures, providing you with an even wider selection of choices. Special Lenses Nikon offers a variety of special-purpose lenses that meet the growing demands of specialized photography.