Canon RF 24-105mm F/4L IS USM vs Canon RF 28-70mm F/2L USM — Which Is Better?

The Canon RF 24-105mm F/4L IS USM and the Canon RF 28-70mm F/2L USM are both full-frame L-series zooms introduced in 2018 for the Canon EOS R system, so either one mounts natively on any Canon RF camera. Both combine a manual rotary zoom ring with an extending barrel, autofocus and a manual focusing ring.

Their roles differ. The 24-105mm is a general-purpose travel zoom covering wide scenes through short telephoto, while the 28-70mm is built around a constant f/2 aperture for low-light event and portrait work.

The 24-105mm is the far lighter and more compact carry. It weighs 700 g against 1430 g for the 28-70mm, roughly half the weight, and measures 107.3 mm long beside 139.8 mm, with an 83.5 mm barrel diameter against 103.8 mm.

Both accept front filters in different sizes, 77mm on the 24-105mm and 95mm on the 28-70mm. Existing 77mm filters fit the smaller lens directly, while the f/2 zoom needs larger glass.

The 28-70mm F/2L is the clear choice for dim venues, holding f/2 across its range where the 24-105mm sits at f/4. Two stops of extra light keep shutter speeds workable at evening weddings and indoor events, with shallower depth of field for portraits.

The 24-105mm answers with framing range. It starts wider at 24mm for architecture and group scenes and reaches 105mm where the 28-70mm stops at 70mm. Its 0.24x maximum magnification against 0.18x suits closer small-object work.

Only the 24-105mm offers built-in image stabilisation, rated at 5 stops, which helps steady handheld shots of static subjects in low light. The 28-70mm has no built-in stabilisation.

Both lenses are weather sealed and carry a zoom lock that stops the extending barrel creeping in a bag. Both also have fluorine coatings that help repel water and oil for easier cleaning.

The 28-70mm uses the more elaborate optical formula: 19 elements in 13 groups, with four aspherical elements, two low-dispersion elements including one super-low-dispersion element. The 24-105mm arranges 18 elements in 14 groups with three aspherical and one low-dispersion element.

Those extra specialised elements in the f/2 zoom support its correction across a much wider aperture. Neither lens uses internal focusing, so the front of the barrel moves during focusing on both.