The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Panasonic 100-300mm F4-5.6 II and the Samyang 300mm f6.3 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 100-300mm F4-5.6 II is the longer of the two lenses at 126mm. The Samyang 300mm f6.3 with a length of 74mm, is 52mm shorter. Besides being longer, the Panasonic 100-300mm F4-5.6 II also has a larger diameter of 74mm compared to the Samyang 300mm f6.3's 65mm 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 300mm f6.3 weighs 318g, 38% (202g) lighter than the Panasonic 100-300mm F4-5.6 II's weight of 520g.
Lens Mounts
Both the Panasonic 100-300mm F4-5.6 II and the Samyang 300mm f6.3 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 300mm f6.3 is also available in Canon EF-M , Fujifilm X and Sony E mounts.
Focal Range
Panasonic 100-300mm F4-5.6 II has a focal range of 100-300mm and
3.0X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
200-600mm when used on a FourThirds format camera.
On the other hand, the Samyang 300mm f6.3 is a prime lens with fixed focal lenght of 300mm which has an effective (full-frame 35mm equivalent) focal range of 600mm when used on a FourThirds format camera.
