The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Olympus ED 8-25mm F4 Pro and the Rokinon 7.5mm 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. Olympus ED 8-25mm F4 Pro is the longer of the two lenses at 89mm. The Rokinon 7.5mm f3.5 Fisheye with a length of 48mm, is 41mm shorter. Besides being longer, the Olympus ED 8-25mm F4 Pro also has a larger diameter of 77mm compared to the Rokinon 7.5mm f3.5 Fisheye'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. Rokinon 7.5mm f3.5 Fisheye weighs 197g, 52% (214g) lighter than the Olympus ED 8-25mm F4 Pro's weight of 411g.
Lens Mounts
Both the Olympus ED 8-25mm F4 Pro and the Rokinon 7.5mm f3.5 Fisheye 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.
Focal Range
Olympus ED 8-25mm F4 Pro has a focal range of 8-25mm and
3.1X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
16-50mm when used on a FourThirds format camera.
On the other hand, the Rokinon 7.5mm 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.
