The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Samyang 20mm F1.8 and the Samyang 7.5mm F3.5 Fisheye MFT 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. Samyang 20mm F1.8 is the longer of the two lenses at 88mm. The Samyang 7.5mm F3.5 Fisheye MFT with a length of 48mm, is 40mm shorter. Besides being longer, the Samyang 20mm F1.8 also has a larger diameter of 83mm compared to the Samyang 7.5mm F3.5 Fisheye MFT's 60mm 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. Samyang 7.5mm F3.5 Fisheye MFT weighs 197g, 60% (300g) lighter than the Samyang 20mm F1.8's weight of 497g.
Below you can find the dimension and weight table of the Wideangle Prime Lenses in Micro Four Thirds Mount for size comparison purposes.
Ultra-Wideangle Lenses in Micro Four Thirds Mount for Size Comparison
Lens Mounts
Both the Samyang 20mm F1.8 and the Samyang 7.5mm F3.5 Fisheye MFT has the same Micro Four Thirds lens mount. Some of the latest released cameras that are compatible with the Micro Four Thirds lenses are OM System OM-3 Astro, OM System OM-5 II and OM System OM-3.
Samyang 20mm F1.8 is also available in the Canon EF , Canon EF-M, Fujifilm X, Nikon F (FX), Pentax KAF, Samsung NX, Sony Alpha and Sony E mounts.
Focal Range
Samyang 20mm F1.8 is a prime lens with fixed focal lenght of 20mm.
On the other hand, the Samyang 7.5mm F3.5 Fisheye MFT 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.
