The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tamron 70-300 F4.5-6.3 Di III 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. Tamron 70-300 F4.5-6.3 Di III is the longer of the two lenses at 148mm. The Sony 500mm F8 Reflex with a length of 118mm, is 30mm shorter. On the other hand, the Sony 500mm F8 Reflex has a larger diameter of 89mm compared to the Tamron 70-300 F4.5-6.3 Di III's 77mm 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. Tamron 70-300 F4.5-6.3 Di III weighs 545g, which means it is 120g (18%) lighter than the Sony 500mm F8 Reflex which has a weight of 665g.
Filter Threads
The Tamron 70-300 F4.5-6.3 Di III has a filter size of 67mm 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 67mm filters that we recommend you to consider for the Tamron 70-300 F4.5-6.3 Di III:
And these are the 55mm filters that we recommend for the Sony 500mm F8 Reflex:
Lens Mounts
The Tamron 70-300 F4.5-6.3 Di III has the Sony E lens mount whereas the Sony 500mm F8 Reflex has the Sony Alpha lens mount. Some of the latest released cameras that are compatible with these mounts are Sony FX5, Sony A7R VI and Sony A7 V for the Sony E Mount and Sony A99 II, Sony A68 and Sony A77 II for the Sony Alpha Mount.
Focal Range
Tamron 70-300 F4.5-6.3 Di III has a focal range of 70-300mm and
4.3X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
105 - 450mm.
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.
