The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Canon 50mm f1.2L 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 50mm f1.2L USM with a length of 66mm, is 31mm shorter. On the other hand, the Canon 50mm f1.2L USM has a larger diameter of 86mm 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% (40g) lighter than the Canon 50mm f1.2L USM's weight of 580g.
Filter Threads
Both the Canon 50mm f1.2L 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
Both the Canon 50mm f1.2L USM and the Canon 28-135mm f3.5-5.6 IS USM has the same Canon EF lens mount. Some of the latest released cameras that are compatible with the Canon EF lenses are Blackmagic URSA 12K LF, Z CAM E2-F6 II 6K and Z CAM E2-S6 II 6K.
Focal Range
Canon 50mm f1.2L USM is a prime lens with fixed focal lenght of 50mm. When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of
80mm.
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.