The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tamron 85mm F1.8 VC and the Sony 135mm F1.8 ZA 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 135mm F1.8 ZA is the longer of the two lenses at 115mm. The Tamron 85mm F1.8 VC with a length of 91mm, is 24mm shorter. Besides being longer, the Sony 135mm F1.8 ZA also has a larger diameter of 89mm compared to the Tamron 85mm F1.8 VC's 85mm 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 85mm F1.8 VC weighs 700g, which means it is 350g (33%) lighter than the Sony 135mm F1.8 ZA which has a weight of 1050g.
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
Filter Threads
The Tamron 85mm F1.8 VC has a filter size of 67mm whereas the Sony 135mm F1.8 ZA has a 77mm 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 85mm F1.8 VC:
And these are the 77mm filters that we recommend for the Sony 135mm F1.8 ZA:
Lens Mounts
Both the Tamron 85mm F1.8 VC and the Sony 135mm F1.8 ZA 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.
Tamron 85mm F1.8 VC is also available in Canon EF and Nikon F (FX) mounts.
Focal Range
Tamron 85mm F1.8 VC is a prime lens with fixed focal lenght of 85mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
127.5mm.
On the other hand, the Sony 135mm F1.8 ZA 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.