The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tamron 35mm F1.8 Di VC USD and the Canon 85mm f1.8 USM 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 35mm F1.8 Di VC USD is the longer of the two lenses at 81mm. The Canon 85mm f1.8 USM with a length of 72mm, is 9mm shorter. Besides being longer, the Tamron 35mm F1.8 Di VC USD also has a larger diameter of 80mm compared to the Canon 85mm f1.8 USM's 75mm 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. Canon 85mm f1.8 USM weighs 425g, 11% (55g) lighter than the Tamron 35mm F1.8 Di VC USD's weight of 480g.
Filter Threads
The Tamron 35mm F1.8 Di VC USD has a filter size of 67mm whereas the Canon 85mm f1.8 USM has a 58mm 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 35mm F1.8 Di VC USD:
And these are the 58mm filters that we recommend for the Canon 85mm f1.8 USM:
Lens Mounts
Both the Tamron 35mm F1.8 Di VC USD and the Canon 85mm f1.8 USM has the same Canon EF lens mount. Some of the latest released cameras that are compatible with the Canon EF lenses are Canon 1D X III, Canon 6D MII and Canon 5D MIV.
Tamron 35mm F1.8 Di VC USD is also available in Nikon F (FX) and Sony Alpha mounts.
Focal Range
Tamron 35mm F1.8 Di VC USD is a prime lens with fixed focal lenght of 35mm. When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of
56mm.
On the other hand, the Canon 85mm f1.8 USM is a prime lens with fixed focal lenght of 85mm. When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of 136mm.