The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Canon 15-85mm f3.5-5.6 IS USM and the Canon 28-135mm f3.5-5.6 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. Canon 28-135mm f3.5-5.6 IS USM is the longer of the two lenses at 97mm. The Canon 15-85mm f3.5-5.6 IS USM with a length of 88mm, is 9mm shorter. On the other hand, the Canon 15-85mm f3.5-5.6 IS USM has a larger diameter of 82mm compared to the Canon 28-135mm f3.5-5.6 IS USM's 78mm 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 28-135mm f3.5-5.6 IS USM weighs 540g, 6% (35g) lighter than the Canon 15-85mm f3.5-5.6 IS USM's weight of 575g.
Filter Threads
Both the Canon 15-85mm f3.5-5.6 IS USM and the Canon 28-135mm f3.5-5.6 IS USM have the same Filter thread size of 72mm.
Below are links to the 72mm filters that we recommend you to consider for these lenses:
Lens Mounts
The Canon 15-85mm f3.5-5.6 IS USM has the Canon EF-S lens mount whereas the Canon 28-135mm f3.5-5.6 IS USM has the Canon EF lens mount. Some of the latest released cameras that are compatible with these mounts are Canon T8i, Canon 90D and Canon SL3 for the Canon EF-S Mount and Blackmagic URSA 12K LF, Z CAM E2-F6 II 6K and Z CAM E2-S6 II 6K for the Canon EF Mount.
Focal Range
Canon 15-85mm f3.5-5.6 IS USM has a focal range of 15-85mm and
5.7X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
24-136mm when used on a APS-C / DX format camera.
On the other hand, the Canon 28-135mm f3.5-5.6 IS USM has a focal range of 28-135mm and 4.8X zoom ratio . When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of 44.8 - 216mm.
