The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sony FE 135mm F1.8 GM and the Sony FE 85mm F1.8 for their suitability to various photography scenarios:
Size and Weight Comparison
Size of a lens is an important deciding factor when comparing two lenses.Sony FE 135mm F1.8 GM is the longer of the two lenses at 127mm. The Sony FE 85mm F1.8 with a length of 82mm is 45mm shorter. Besides being longer, the Sony FE 135mm F1.8 GM also has a larger diameter of 90mm compared to Sony FE 85mm F1.8's 78mm diameter.
Below you can find the scaled side by side image of Sony FE 135mm F1.8 GM and Sony FE 85mm F1.8 to get a better idea of how their size compare in real life.
Weight of a lens is as important as its external dimensions, especially if you are planning to hand hold your camera and lens combination for longer periods. Sony FE 85mm F1.8 weighs 371g, 60% (579g) lighter than the Sony FE 135mm F1.8 GM's weight of 950g.
Below you can find the dimension and weight table of the 'Telephoto Prime Lenses in Sony E Mount for size comparison purposes.
Telephoto Prime Lenses in Sony E Mount for Size Comparison
Both Sony FE 135mm F1.8 GM and Sony FE 85mm F1.8 has the same Sony E lens mount. Some of the latest released cameras that are compatible with the Sony E lenses are Sony A7R V, Sony FX30 and Sony A7 IV.
Sony FE 135mm F1.8 GM 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 an 35mm (FF) equivalent of 202.5mm.
Sony FE 85mm F1.8 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 an 35mm (FF) equivalent of 127.5mm.