The F-number of a photographic lens is a measure of its light-gathering ability, and is expressed as its aperture diameter ...

The Viltrox AF 50mm f/2 Air aims for a compact and lightweight build at a budget price, without sacrificing performance ...

Central sharpness is excellent at f/2.8, outstanding from f/4 to f/8 and ... The taller the column, the better the lens performance. CA (Chromatic Aberration) is measured with in-camera ...