The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tamron AF 28-75mm f2.8 XR LD and the Canon 24-85mm f3.5-4.5 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.Tamron AF 28-75mm f2.8 XR LD is the longer of the two lenses at 92mm. The Canon 24-85mm f3.5-4.5 USM with a length of 70mm is 22mm shorter. On the other hand, there is no difference between the max diameters of these lenses, both coming at 73mm.
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 24-85mm f3.5-4.5 USM weighs 380g, 25% (130g) lighter than the Tamron AF 28-75mm f2.8 XR LD's weight of 510g.
Below you can find the dimension and weight table of the 'Standard Zoom Lenses in Canon EF Mount for size comparison purposes.
Standard Zoom Lenses in Canon EF Mount for Size Comparison
Both Tamron AF 28-75mm f2.8 XR LD and Canon 24-85mm 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 1D X III, Canon 6D MII and Canon 5D MIV.
Tamron AF 28-75mm f2.8 XR LD is also available in Nikon F (FX) , Sony Alpha and Pentax KAF mounts.
Tamron AF 28-75mm f2.8 XR LD has a focal range of 28-75mm and 2.7X zoom ratio . When it is mounted on an APS-C sensor camera with 1.6x crop, it provides an 35mm (FF) equivalent of 44.8 - 120mm.
Canon 24-85mm f3.5-4.5 USM has a focal range of 24-85mm and 3.5X zoom ratio . When it is mounted on an APS-C sensor camera with 1.6x crop, it provides an 35mm (FF) equivalent of 38.4 - 136mm.