The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 20mm F1.4 DG HSM A and the Panasonic Fisheye 8mm F3.5 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 20mm F1.4 DG HSM A is the longer of the two lenses at 130mm. The Panasonic Fisheye 8mm F3.5 with a length of 52mm, is 78mm shorter. Besides being longer, the Sigma 20mm F1.4 DG HSM A also has a larger diameter of 91mm compared to the Panasonic Fisheye 8mm F3.5'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. Panasonic Fisheye 8mm F3.5 weighs 165g, 82% (785g) lighter than the Sigma 20mm F1.4 DG HSM A's weight of 950g.
Lens Mounts
The Sigma 20mm F1.4 DG HSM A has the Leica L lens mount whereas the Panasonic Fisheye 8mm F3.5 has the Micro Four Thirds lens mount. Some of the latest released cameras that are compatible with these mounts are Leica SL3-P, Panasonic S1 II and Panasonic S1 IIE for the Leica L Mount and OM System OM-3 Astro, OM System OM-5 II and OM System OM-3 for the Micro Four Thirds Mount.
Sigma 20mm F1.4 DG HSM A is also available in the Canon EF , Nikon F (FX) and Sigma SA mounts.
Focal Range
Sigma 20mm F1.4 DG HSM A is a prime lens with fixed focal lenght of 20mm.
On the other hand, the Panasonic Fisheye 8mm F3.5 is a prime lens with fixed focal lenght of 8mm which has an effective (full-frame 35mm equivalent) focal range of 16mm when used on a FourThirds format camera.
