The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Canon 18-135mm f3.5-5.6 IS STM and the Canon 75-300mm f4.0-5.6 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 75-300mm f4.0-5.6 IS USM is the longer of the two lenses at 138mm. The Canon 18-135mm f3.5-5.6 IS STM with a length of 96mm, is 42mm shorter. Besides being longer, the Canon 75-300mm f4.0-5.6 IS USM also has a larger diameter of 79mm compared to the Canon 18-135mm f3.5-5.6 IS STM's 77mm 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 18-135mm f3.5-5.6 IS STM weighs 480g, which means it is 170g (26%) lighter than the Canon 75-300mm f4.0-5.6 IS USM which has a weight of 650g.
Filter Threads
The Canon 18-135mm f3.5-5.6 IS STM has a filter size of 67mm whereas the Canon 75-300mm f4.0-5.6 IS USM has a 58mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 67mm filters that we recommend you to consider for the Canon 18-135mm f3.5-5.6 IS STM:
And these are the 58mm filters that we recommend for the Canon 75-300mm f4.0-5.6 IS USM:
Lens Mounts
The Canon 18-135mm f3.5-5.6 IS STM has the Canon EF-S lens mount whereas the Canon 75-300mm f4.0-5.6 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 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.
On the other hand, the Canon 75-300mm f4.0-5.6 IS USM has a focal range of 75-300mm and 4.0X zoom ratio . When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of 120 - 480mm.
