The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tamron 17-50mm f2.8 XR II VC LD and the Canon 17-85mm 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. Tamron 17-50mm f2.8 XR II VC LD is the longer of the two lenses at 95mm. The Canon 17-85mm f4-5.6 IS USM with a length of 92mm, is 3mm shorter. Besides being longer, the Tamron 17-50mm f2.8 XR II VC LD also has a larger diameter of 80mm compared to the Canon 17-85mm f4-5.6 IS USM's 79mm 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 17-85mm f4-5.6 IS USM weighs 475g, 16% (95g) lighter than the Tamron 17-50mm f2.8 XR II VC LD's weight of 570g.
Filter Threads
The Tamron 17-50mm f2.8 XR II VC LD has a filter size of 72mm whereas the Canon 17-85mm f4-5.6 IS USM has a 67mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 72mm filters that we recommend you to consider for the Tamron 17-50mm f2.8 XR II VC LD:
And these are the 67mm filters that we recommend for the Canon 17-85mm f4-5.6 IS USM:
Lens Mounts
The Tamron 17-50mm f2.8 XR II VC LD has the Nikon F (DX) lens mount whereas the Canon 17-85mm f4-5.6 IS USM has the Canon EF-S lens mount. Some of the latest released cameras that are compatible with these mounts are Nikon D3500, Nikon D7500 and Nikon D5600 for the Nikon F (DX) Mount and Canon T8i, Canon 90D and Canon SL3 for the Canon EF-S Mount.
Tamron 17-50mm f2.8 XR II VC LD is also available in the Canon EF mount.
Focal Range
Tamron 17-50mm f2.8 XR II VC LD has a focal range of 17-50mm and
2.9X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
25.5-75mm when used on a APS-C / DX format camera.
On the other hand, the Canon 17-85mm f4-5.6 IS USM has a focal range of 17-85mm and 5.0X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 27.2-136mm when used on a APS-C / DX format camera.
