The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Canon 24-105mm F4L IS II 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. Canon 24-105mm F4L IS II is the longer of the two lenses at 118mm. The Canon 17-85mm f4-5.6 IS USM with a length of 92mm, is 26mm shorter. Besides being longer, the Canon 24-105mm F4L IS II also has a larger diameter of 84mm 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, 40% (320g) lighter than the Canon 24-105mm F4L IS II's weight of 795g.
Filter Threads
The Canon 24-105mm F4L IS II has a filter size of 77mm 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 77mm filters that we recommend you to consider for the Canon 24-105mm F4L IS II:
And these are the 67mm filters that we recommend for the Canon 17-85mm f4-5.6 IS USM:
Lens Mounts
The Canon 24-105mm F4L IS II has the Canon EF 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 Blackmagic URSA 12K LF, Z CAM E2-F6 II 6K and Z CAM E2-S6 II 6K for the Canon EF Mount and Canon T8i, Canon 90D and Canon SL3 for the Canon EF-S Mount.
Focal Range
Canon 24-105mm F4L IS II has a focal range of 24-105mm and
4.4X zoom ratio . When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of
38.4 - 168mm.
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.