The type of photography that you are planning to use is an important decision factor. Here we have evaluated the AstrHori 6mm f2.8 and the Sigma 12mm f1.4 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. Sigma 12mm f1.4 is the longer of the two lenses at 67mm. The AstrHori 6mm f2.8 with a length of 61mm, is 6mm shorter. Besides being longer, the Sigma 12mm f1.4 also has a larger diameter of 69mm compared to the AstrHori 6mm f2.8's 65mm 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. Sigma 12mm f1.4 weighs 250g, 26% (90g) lighter than the AstrHori 6mm f2.8's weight of 340g.
Below you can find the dimension and weight table of the Wideangle Fisheye Prime Lenses in Canon RF Mount for size comparison purposes.
Ultra-Wideangle Lenses in Canon RF Mount for Size Comparison
Lens Mounts
Both the AstrHori 6mm f2.8 and the Sigma 12mm f1.4 has the same Canon RF lens mount. Some of the latest released cameras that are compatible with the Canon RF lenses are Canon R6 V, Canon R6 III and Canon C50.
AstrHori 6mm f2.8 is also available in the Sony E , Nikon Z and Leica L mounts.
Sigma 12mm f1.4 is also available in Sony E and Fujifilm X mounts.
Focal Range
AstrHori 6mm f2.8 is a prime lens with fixed focal lenght of 6mm. When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of
9.6mm.
On the other hand, the Sigma 12mm f1.4 is a prime lens with fixed focal lenght of 12mm which has an effective (full-frame 35mm equivalent) focal range of 18mm when used on a APS-C / DX format camera.
