The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Canon RF-S 10-18mm F4.5-6.3 and the Canon RF 10-20mm F4 L 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 RF 10-20mm F4 L IS STM is the longer of the two lenses at 112mm. The Canon RF-S 10-18mm F4.5-6.3 with a length of 45mm, is 67mm shorter. Besides being longer, the Canon RF 10-20mm F4 L IS STM also has a larger diameter of 84mm compared to the Canon RF-S 10-18mm F4.5-6.3's 69mm diameter.
Below you can find a scaled side-by-side image of Canon RF-S 10-18mm F4.5-6.3 and Canon RF 10-20mm F4 L IS STM to get a better idea of how their sizes compare in real life.
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-S 10-18mm F4.5-6.3 weighs 150g, which means it is 420g (73%) lighter than the Canon RF 10-20mm F4 L IS STM which has a weight of 570g.
Below you can find the dimension and weight table of the Wideangle Zoom Lenses in Canon RF Mount for size comparison purposes.
Ultra-Wideangle Lenses in Canon RF Mount for Size Comparison
Both the Canon RF-S 10-18mm F4.5-6.3 and the Canon RF 10-20mm F4 L IS STM has the same Canon RF lens mount. Some of the latest released cameras that are compatible with the Canon RF lenses are Canon R100, Canon R50 and Canon R10.
Canon RF-S 10-18mm F4.5-6.3 has a focal range of 10-18mm and 1.8X
zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 16-28.8mm
when used on a APS-C / DX format camera.
On the other hand, the Canon RF 10-20mm F4 L IS STM has a focal range of 10-20mm and 2.0X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 15 - 30mm.