The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Canon RF 135mm F1.8 L IS USM and the Canon 135mm f2.0L USM for their suitability to various photography scenarios:
Size and Weight Comparison
The size of a lens is an important deciding factor when comparing two lenses. Canon RF 135mm F1.8 L IS USM is the longer of the two lenses at 130mm. The Canon 135mm f2.0L USM with a length of 112mm, is 18mm shorter. Besides being longer, the Canon RF 135mm F1.8 L IS USM also has a larger diameter of 89mm compared to the Canon 135mm f2.0L USM's 83mm diameter.
The weight of a lens is as important as its external dimensions, especially if you are planning to hand hold your camera and lens combination for longer periods. Canon 135mm f2.0L USM weighs 750g, 19% (185g) lighter than the Canon RF 135mm F1.8 L IS USM's weight of 935g.
The Canon RF 135mm F1.8 L IS USM has the Canon RF lens mount whereas the Canon 135mm f2.0L USM has the Canon EF lens mount. Some of the latest released cameras that are compatible with these mounts are Canon R8, Canon R50 and Canon R6 II for the Canon RF Mount and Canon 1D X III, Canon 6D MII and Canon 5D MIV for the Canon EF Mount.
Both lenses have the same focal range of 135mm but while Canon RF 135mm F1.8 L IS USM has the fastest aperture of F1.8, the Canon 135mm f2.0L USM's widest aperture value is F2.0.