The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Panasonic 8-18mm F2.8-4.0 ASPH 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. Panasonic 8-18mm F2.8-4.0 ASPH is the longer of the two lenses at 88mm. The Rokinon 7.5mm f3.5 Fisheye with a length of 48mm, is 40mm shorter. Besides being longer, the Panasonic 8-18mm F2.8-4.0 ASPH also has a larger diameter of 73mm 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, 37% (118g) lighter than the Panasonic 8-18mm F2.8-4.0 ASPH's weight of 315g.
Lens Mounts
Both the Panasonic 8-18mm F2.8-4.0 ASPH 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
Panasonic 8-18mm F2.8-4.0 ASPH has a focal range of 8-18mm and
2.3X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
16-36mm 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.
