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 Canon 70-300mm f4-5.6 IS 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. Canon 70-300mm f4-5.6 IS USM is the longer of the two lenses at 143mm. The Tamron 85mm F1.8 VC with a length of 91mm, is 52mm shorter. On the other hand, the Tamron 85mm F1.8 VC has a larger diameter of 85mm compared to the Canon 70-300mm f4-5.6 IS USM's 77mm 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 70-300mm f4-5.6 IS USM weighs 630g, 9% (70g) lighter than the Tamron 85mm F1.8 VC's weight of 700g.
Filter Threads
The Tamron 85mm F1.8 VC has a filter size of 67mm whereas the Canon 70-300mm f4-5.6 IS 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 85mm F1.8 VC:
And these are the 58mm filters that we recommend for the Canon 70-300mm f4-5.6 IS USM:
Lens Mounts
Both the Tamron 85mm F1.8 VC and the Canon 70-300mm f4-5.6 IS USM has the same Canon EF lens mount. Some of the latest released cameras that are compatible with the Canon EF lenses are Blackmagic URSA 12K LF, Z CAM E2-F6 II 6K and Z CAM E2-S6 II 6K.
Tamron 85mm F1.8 VC is also available in the Sony Alpha 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 1.6x crop, it provides a 35mm (FF) equivalent of
136mm.
On the other hand, the Canon 70-300mm f4-5.6 IS USM has a focal range of 70-300mm and 4.3X zoom ratio . When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of 112 - 480mm.
