The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sony 20mm F2.8 and the Sony 16mm F2.8 Fisheye for their suitability to various photography scenarios:
Size and Weight Comparison
The size of a lens is a crucial factor to consider when comparing two lenses. Sony 16mm F2.8 Fisheye is the longer of the two lenses at 67mm. The Sony 20mm F2.8 with a length of 54mm, is 13mm shorter. On the other hand, the Sony 20mm F2.8 has a larger diameter of 78mm compared to the Sony 16mm F2.8 Fisheye's 75mm diameter.
The weight of a lens is equally significant as its external dimensions, particularly if you intend to handhold your camera and lens combination for extended periods. Sony 20mm F2.8 weighs 285g, which means it is 115g (28%) lighter than the Sony 16mm F2.8 Fisheye which has a weight of 400g.
Below you can find the dimension and weight table of the Wideangle Prime Lenses in Sony Alpha Mount for size comparison purposes.
Ultra-Wideangle Lenses in Sony Alpha Mount for Size Comparison
Lens Mounts
Both the Sony 20mm F2.8 and the Sony 16mm F2.8 Fisheye has the same Sony Alpha lens mount. Some of the latest released cameras that are compatible with the Sony Alpha lenses are Sony A99 II, Sony A68 and Sony A77 II.
Focal Range
Sony 20mm F2.8 is a prime lens with fixed focal lenght of 20mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
30mm.
On the other hand, the Sony 16mm F2.8 Fisheye is a prime lens with fixed focal lenght of 16mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 24mm.
