The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tamron 10-24mm f3.5-4.5 II LD and the Canon 20-35mm f3.5-4.5 USM for their suitability to various photography scenarios:
Size and Weight Comparison
The size of a lens is an important deciding factor when comparing two lenses. Tamron 10-24mm f3.5-4.5 II LD is the longer of the two lenses at 84mm. The Canon 20-35mm f3.5-4.5 USM with a length of 69mm, is 15mm shorter. On the other hand, the Canon 20-35mm f3.5-4.5 USM has a larger diameter of 84mm compared to the Tamron 10-24mm f3.5-4.5 II LD's 83mm diameter.
The 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. Canon 20-35mm f3.5-4.5 USM weighs 340g, 16% (66g) lighter than the Tamron 10-24mm f3.5-4.5 II LD's weight of 406g.
Below you can find the dimension and weight table of the Wideangle Zoom Lenses in Canon EF Mount for size comparison purposes.
Wideangle Zoom Lenses in Canon EF Mount for Size Comparison
Lens Mounts
Both the Tamron 10-24mm f3.5-4.5 II LD and the Canon 20-35mm f3.5-4.5 USM has the same Canon EF lens mount. Some of the latest released cameras that are compatible with the Canon EF lenses are Canon T8i, Canon 90D and Canon SL3.
Tamron 10-24mm f3.5-4.5 II LD is also available in Nikon F (DX) , Sony Alpha, Pentax KAF and Canon EF mounts.
Focal Range
Tamron 10-24mm f3.5-4.5 II LD has a focal range of 10-24mm and 2.4X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 16-38.4mm when used on a APS-C / DX format camera. Canon 20-35mm f3.5-4.5 USM has a focal range of 20-35mm and 1.8X zoom ratio . When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of 32 - 56mm.