The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Canon RF 20-50mm F4 and the Canon RF 28-70mm F2.8 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 20-50mm F4 is the longer of the two lenses at 98mm. The Canon RF 28-70mm F2.8 with a length of 92mm, is 6mm shorter. Besides being longer, the Canon RF 20-50mm F4 also has a larger diameter of 80mm compared to the Canon RF 28-70mm F2.8's 77mm 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 20-50mm F4 weighs 420g, which means it is 74g (14%) lighter than the Canon RF 28-70mm F2.8 which has a weight of 494g.
Below you can find the dimension and weight table of the Standard Zoom Lenses in Canon RF Mount for size comparison purposes.
Standard Lenses in Canon RF Mount for Size Comparison
Filter Threads
Both the Canon RF 20-50mm F4 and the Canon RF 28-70mm F2.8 have the same Filter thread size of 67mm.
Below are links to the 67mm filters that we recommend you to consider for these lenses:
Lens Mounts
Both the Canon RF 20-50mm F4 and the Canon RF 28-70mm F2.8 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.
Focal Range
Canon RF 20-50mm F4 has a focal range of 20-50mm and
2.5X zoom ratio . When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of
32 - 80mm.
On the other hand, the Canon RF 28-70mm F2.8 has a focal range of 28-70mm and 2.5X 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 - 112mm.
