The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Venus Laowa 4mm F2.8 E and the Tamron 20mm F2.8 Di III OSD M1:2 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. Tamron 20mm F2.8 Di III OSD M1:2 is the longer of the two lenses at 64mm. The Venus Laowa 4mm F2.8 E with a length of 26mm, is 38mm shorter. Besides being longer, the Tamron 20mm F2.8 Di III OSD M1:2 also has a larger diameter of 73mm compared to the Venus Laowa 4mm F2.8 E's 61mm 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. Venus Laowa 4mm F2.8 E weighs 135g, which means it is 85g (38%) lighter than the Tamron 20mm F2.8 Di III OSD M1:2 which has a weight of 220g.
Below you can find the dimension and weight table of the Wideangle Fisheye Prime Lenses in Sony E Mount for size comparison purposes.
Ultra-Wideangle Lenses in Sony E Mount for Size Comparison
Lens Mounts
Both the Venus Laowa 4mm F2.8 E and the Tamron 20mm F2.8 Di III OSD M1:2 has the same Sony E lens mount. Some of the latest released cameras that are compatible with the Sony E lenses are Sony ZV-E10 II, Sony A6700 and Sony FX30.
Focal Range
Venus Laowa 4mm F2.8 E is a prime lens with fixed focal lenght of 4mm which has an effective (full-frame 35mm equivalent) focal range of
6mm when used on a APS-C / DX format camera.
On the other hand, the Tamron 20mm F2.8 Di III OSD M1:2 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.
