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 24-70mm f4L 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 24-70mm f4L IS USM is the longer of the two lenses at 93mm. The Canon 15-85mm f3.5-5.6 IS USM with a length of 88mm, is 5mm shorter. Besides being longer, the Canon 24-70mm f4L IS USM also has a larger diameter of 83mm compared to the Canon 15-85mm f3.5-5.6 IS USM's 82mm 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 15-85mm f3.5-5.6 IS USM weighs 575g, which means it is 25g (4%) lighter than the Canon 24-70mm f4L IS USM which has a weight of 600g.
Filter Threads
The Canon 15-85mm f3.5-5.6 IS USM has a filter size of 72mm whereas the Canon 24-70mm f4L IS USM has a 77mm 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 Canon 15-85mm f3.5-5.6 IS USM:
And these are the 77mm filters that we recommend for the Canon 24-70mm f4L IS USM:
Lens Mounts
The Canon 15-85mm f3.5-5.6 IS USM has the Canon EF-S lens mount whereas the Canon 24-70mm f4L 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 24-70mm f4L IS USM has a focal range of 24-70mm and 2.9X 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 - 112mm.
