The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tamron AF 70-300mm f4-5.6 LD 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 AF 70-300mm f4-5.6 LD is the longer of the two lenses at 117mm. The Canon 85mm f1.8 USM with a length of 72mm, is 45mm shorter. Besides being longer, the Tamron AF 70-300mm f4-5.6 LD also has a larger diameter of 77mm 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, 2% (10g) lighter than the Tamron AF 70-300mm f4-5.6 LD's weight of 435g.
Filter Threads
The Tamron AF 70-300mm f4-5.6 LD has a filter size of 62mm 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 62mm filters that we recommend you to consider for the Tamron AF 70-300mm f4-5.6 LD:
And these are the 58mm filters that we recommend for the Canon 85mm f1.8 USM:
Lens Mounts
Both the Tamron AF 70-300mm f4-5.6 LD 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 Blackmagic URSA 12K LF, Z CAM E2-F6 II 6K and Z CAM E2-S6 II 6K.
Tamron AF 70-300mm f4-5.6 LD is also available in the Nikon F (FX) , Sony Alpha and Pentax KAF mounts.
Focal Range
Tamron AF 70-300mm f4-5.6 LD 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.
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.
