20.1 How to Choose a Lens
There are many parameters that define a good lens and separate a good lens from a bad one. For High Definition (HD) cinematography, where there is a mixture of both film and video backgrounds, the most important include resolution (i.e. what is the smallest dot in the scene that can accurately be recorded?), contrast (does the lens have a short, hard tonal range or a long, gentle one?), color rendition (this breaks down into two separate parameters: the overall color hue of the image and edge fringing) and, finally, breathing (which describes the effect of an image size change when the lens focus is racked).
There are many ways to define the resolution of a lens but the simplest is ...