The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 10-20mm F4-5.6 EX DC HSM and the Olympus ED 8mm f3.5 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. Sigma 10-20mm F4-5.6 EX DC HSM is the longer of the two lenses at 81mm. The Olympus ED 8mm f3.5 Fisheye with a length of 77mm, is 4mm shorter. Besides being longer, the Sigma 10-20mm F4-5.6 EX DC HSM also has a larger diameter of 84mm compared to the Olympus ED 8mm f3.5 Fisheye's 79mm 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 10-20mm F4-5.6 EX DC HSM weighs 470g, which means it is 15g (3%) lighter than the Olympus ED 8mm f3.5 Fisheye which has a weight of 485g.
Lens Mounts
Both the Sigma 10-20mm F4-5.6 EX DC HSM and the Olympus ED 8mm f3.5 Fisheye has the same Four Thirds lens mount. Some of the latest released cameras that are compatible with the Four Thirds lenses are , and .
Sigma 10-20mm F4-5.6 EX DC HSM is also available in the Canon EF , Pentax KAF, Sony Alpha, Sigma SA and Nikon F (DX) mounts.
Focal Range
Sigma 10-20mm F4-5.6 EX DC HSM has a focal range of 10-20mm and
2.0X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
15-30mm when used on a APS-C / DX format camera.
On the other hand, the Olympus ED 8mm f3.5 Fisheye 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.
