The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Venus Laowa 15mm f5 and the Canon RF-S 7.8mm F4 STM Dual 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-S 7.8mm F4 STM Dual is the longer of the two lenses at 42mm. The Venus Laowa 15mm f5 with a length of 25mm, is 17mm shorter. Besides being longer, the Canon RF-S 7.8mm F4 STM Dual also has a larger diameter of 69mm compared to the Venus Laowa 15mm f5's 53mm 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, 17% (27g) lighter than the Venus Laowa 15mm f5's weight of 158g.
Below you can find the dimension and weight table of the Wideangle Prime Lenses in Canon RF Mount for size comparison purposes.
Ultra-Wideangle Lenses in Canon RF Mount for Size Comparison
Filter Threads
The Venus Laowa 15mm f5 has a filter size of 39mm whereas the Canon RF-S 7.8mm F4 STM Dual 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 39mm filters that we recommend you to consider for the Venus Laowa 15mm f5:
And these are the 58mm filters that we recommend for the Canon RF-S 7.8mm F4 STM Dual:
Lens Mounts
Both the Venus Laowa 15mm f5 and the Canon RF-S 7.8mm F4 STM Dual has the same Canon RF lens mount. Some of the latest released cameras that are compatible with the Canon RF lenses are Canon R6 V, Canon R6 III and Canon C50.
Venus Laowa 15mm f5 is also available in the Sony E , Nikon Z and Leica L mounts.
Focal Range
Venus Laowa 15mm f5 is a prime lens with fixed focal lenght of 15mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
22.5mm.
On the other hand, the 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.
