The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Samyang 300mm f6.3 and the Sony 500mm F8 Reflex 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. Sony 500mm F8 Reflex is the longer of the two lenses at 118mm. The Samyang 300mm f6.3 with a length of 74mm, is 44mm shorter. Besides being longer, the Sony 500mm F8 Reflex also has a larger diameter of 89mm 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 260g, which means it is 405g (60%) lighter than the Sony 500mm F8 Reflex which has a weight of 665g.
Below you can find the dimension and weight table of the Telephoto Mirror Prime Lenses in Sony Alpha Mount for size comparison purposes.
Super Telephoto Lenses in Sony Alpha Mount for Size Comparison
Filter Threads
The Samyang 300mm f6.3 has a filter size of 26mm whereas the Sony 500mm F8 Reflex has a 55mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 26mm filters that we recommend you to consider for the Samyang 300mm f6.3:
And these are the 55mm filters that we recommend for the Sony 500mm F8 Reflex:
Lens Mounts
Both the Samyang 300mm f6.3 and the Sony 500mm F8 Reflex has the same Sony Alpha lens mount. Some of the latest released cameras that are compatible with the Sony Alpha lenses are Sony A68, Sony A77 II and Sony A58.
Samyang 300mm f6.3 is also available in the Canon EF , Nikon F (DX) and Four Thirds mounts.
Focal Range
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
450mm when used on a APS-C / DX format camera.
On the other hand, the Sony 500mm F8 Reflex is a prime lens with fixed focal lenght of 500mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 750mm.
