The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Canon RF-S 7.8mm F4 STM Dual and the Canon 50mm f1.2L 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 50mm f1.2L USM is the longer of the two lenses at 66mm. The Canon RF-S 7.8mm F4 STM Dual with a length of 42mm, is 24mm shorter. Besides being longer, the Canon 50mm f1.2L USM also has a larger diameter of 86mm compared to the Canon RF-S 7.8mm F4 STM Dual's 69mm 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 RF-S 7.8mm F4 STM Dual weighs 131g, which means it is 449g (77%) lighter than the Canon 50mm f1.2L USM which has a weight of 580g.
Filter Threads
The Canon RF-S 7.8mm F4 STM Dual has a filter size of 58mm whereas the Canon 50mm f1.2L USM has a 72mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 58mm filters that we recommend you to consider for the Canon RF-S 7.8mm F4 STM Dual:
And these are the 72mm filters that we recommend for the Canon 50mm f1.2L USM:
Lens Mounts
The Canon RF-S 7.8mm F4 STM Dual has the Canon RF lens mount whereas the Canon 50mm f1.2L USM has the Canon EF lens mount. Some of the latest released cameras that are compatible with these mounts are Canon R50 V, Canon R100 and Canon R50 for the Canon RF 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 RF-S 7.8mm F4 STM Dual is a prime lens with fixed focal lenght of 7.8mm which has an effective (full-frame 35mm equivalent) focal range of
12.8mm when used on a APS-C / DX format camera.
On the other hand, the 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.
