The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sony 300mm F2.8 G SSM II and the Sony 135mm F2.8 (T4.5) STF 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 300mm F2.8 G SSM II is the longer of the two lenses at 243mm. The Sony 135mm F2.8 (T4.5) STF with a length of 99mm, is 144mm shorter. Besides being longer, the Sony 300mm F2.8 G SSM II also has a larger diameter of 122mm compared to the Sony 135mm F2.8 (T4.5) STF's 80mm 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. Sony 135mm F2.8 (T4.5) STF weighs 730g, 68% (1570g) lighter than the Sony 300mm F2.8 G SSM II's weight of 2300g.
Below you can find the dimension and weight table of the Telephoto Prime Lenses in Sony Alpha Mount for size comparison purposes.
Telephoto Lenses in Sony Alpha Mount for Size Comparison
Lens Mounts
Both the Sony 300mm F2.8 G SSM II and the Sony 135mm F2.8 (T4.5) STF has the same Sony Alpha lens mount. Some of the latest released cameras that are compatible with the Sony Alpha lenses are Sony A99 II, Sony A68 and Sony A77 II.
Focal Range
Sony 300mm F2.8 G SSM II is a prime lens with fixed focal lenght of 300mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
450mm.
On the other hand, the Sony 135mm F2.8 (T4.5) STF is a prime lens with fixed focal lenght of 135mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 202.5mm.