The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tokina 12-28mm f4 Pro DX and the Canon 17-40mm f4.0L USM for their suitability to various photography scenarios:
Size and Weight Comparison
Size of a lens is an important deciding factor when comparing two lenses.Canon 17-40mm f4.0L USM is the longer of the two lenses at 97mm. The Tokina 12-28mm f4 Pro DX with a length of 90mm is 7mm shorter. On the other hand, there is no difference between the max diameters of these lenses, both coming at 84mm.
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 17-40mm f4.0L USM weighs 500g, 5% (30g) lighter than the Tokina 12-28mm f4 Pro DX's weight of 530g.
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 Tokina 12-28mm f4 Pro DX and Canon 17-40mm f4.0L 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.
Tokina 12-28mm f4 Pro DX is also available in Nikon F (DX) mount.
Focal Range
Tokina 12-28mm f4 Pro DX has a focal range of 12-28mm and 2.3X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 19.2-44.8mm when used on a APS-C / DX format camera. Canon 17-40mm f4.0L USM has a focal range of 17-40mm and 2.4X zoom ratio . When it is mounted on an APS-C sensor camera with 1.6x crop, it provides an 35mm (FF) equivalent of 27.2 - 64mm.