Size and Weight Comparison
Size of a lens is an important deciding factor when comparing two lenses.Sigma 85mm F1.4 DG DN is the longer of the two lenses at 94mm. The Sigma 90mm F2.8 DG DN C with a length of 60mm is 34mm shorter. Besides being longer, the Sigma 85mm F1.4 DG DN also has a larger diameter of 83mm compared to Sigma 90mm F2.8 DG DN C's 64mm diameter.
Below you can find the scaled side by side image of Sigma 90mm F2.8 DG DN C and Sigma 85mm F1.4 DG DN 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. Sigma 90mm F2.8 DG DN C weighs 295g, which means it is 335g (53%) lighter than the Sigma 85mm F1.4 DG DN which has a weight of 630g.
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 Sigma 90mm F2.8 DG DN C and Sigma 85mm F1.4 DG DN has the same Sony E lens mount. Some of the latest released cameras that are compatible with the Sony E lenses are Sony FX30, Sony ZV-E10 and Sony A6600.
Sigma 90mm F2.8 DG DN C is also available in Leica L mount.
Sigma 90mm F2.8 DG DN C is a prime lens with fixed focal lenght of 90mm which has a 35mm equivalent focal range of 135mm when used on a 35mm FF format camera. Sigma 85mm F1.4 DG DN 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.