The lens feature of food documentary is standard fixed focus lens. Primelens refers to a lens with fixed focal length, no focal length or only one field of view. Fixed focus lens has no zoom function.

The design of fixed-focus lens is much simpler than that of zoom lens, but the general zoom lens will affect the imaging when zooming. The biggest advantage of fixed-focus lens compared with zoom machine is its fast focusing speed and stable imaging quality. Many digital cameras with fixed-focus lenses have clear and stable images of moving objects, very accurate focusing, delicate pictures, very slight graininess and relatively accurate metering.