The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Canon RF 24-105mm F4.0-7.1 IS and the Canon 18-135mm f3.5-5.6 IS STM 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 18-135mm f3.5-5.6 IS STM is the longer of the two lenses at 96mm. The Canon RF 24-105mm F4.0-7.1 IS with a length of 89mm, is 7mm shorter. On the other hand, there is no difference between the max diameters of these lenses, both coming at 77mm.
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 RF 24-105mm F4.0-7.1 IS weighs 395g, which means it is 85g (17%) lighter than the Canon 18-135mm f3.5-5.6 IS STM which has a weight of 480g.
Filter Threads
Both the Canon RF 24-105mm F4.0-7.1 IS and the Canon 18-135mm f3.5-5.6 IS STM have the same Filter thread size of 67mm.
Below are links to the 67mm filters that we recommend you to consider for these lenses:
Lens Mounts
The Canon RF 24-105mm F4.0-7.1 IS has the Canon RF lens mount whereas the Canon 18-135mm f3.5-5.6 IS STM has the Canon EF-S lens mount. Some of the latest released cameras that are compatible with these mounts are Canon R100, Canon R8 and Canon R50 for the Canon RF Mount and Canon T8i, Canon 90D and Canon SL3 for the Canon EF-S Mount.
Focal Range
Canon RF 24-105mm F4.0-7.1 IS 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 18-135mm f3.5-5.6 IS STM has a focal range of 18-135mm and 7.5X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 28.8-216mm when used on a APS-C / DX format camera.