Canon has announced the RF 10-20mm f/4 L IS STM, price tag £2579.99 / $2,299 / €2929.99, an ultra-wide-angle lens that is seen as the RF-mount successor to the Canon EF 11-24mm f/4 L USM. The new Canon RF 10-20mm f/4 L IS STM is also the widest full-frame lens with autofocus.
- Read our early Canon RF 10-20mm f/4 L IS STM review
![Left: Canon RF 10-20mm f/4 L IS STM, Right: Canon EF 11-24mm f/4 L USM](https://b826082.smushcdn.com/826082/wp-content/uploads/2023/10/Canon-RF-10-20mm-f_4-L-IS-STM-0A_DSC2905-©ANicholson.jpg?lossy=2&strip=1&webp=1)
An ultra-wide lens like the RF 10-20mm f/4 L IS STM is ideal for landscape, architecture and interior photography, and videography.
According to Canon, the new lens is better featured than the EF 11-24mm f/4 LUSM and produces better quality results. It also has the advantage of the RF mount, which is wider than the EF mount and has 12-pins for faster communication with the camera.
The RF 10-20mm f/4 L IS STM is constructed from 16 elements arranged in 12 groups with glass moulded aspherical elements and both UD and Super UD glass. Canon has also applied state-of-the-art optical coatings to minimise flare and reflections.
Thanks to an advanced rectilinear design, with a 130° angle of view, the new lens is said to suffer from minimal distortion, so straight lines are straight, even at the corners of the frame.
![Canon RF 10-20mm f/4 L IS STM front element](https://b826082.smushcdn.com/826082/wp-content/uploads/2023/10/Canon-RF-10-20mm-f_4-L-IS-STM-0A_DSC2903-©ANicholson.jpg?lossy=2&strip=1&webp=1)
In a first for a Canon L lens, the RF 10-20mm f/4 L IS STM features an STM autofocus system. This is optimised for linear focusing, which is ideal for smooth transitions during video. The focusing system also has a positioning sensor which means the lens doesn’t have to reset when the camera is turned on and off. Consequently, the lens is ready for action a fraction quicker than a standard lens. There’s also full-time manual focusing when the focus needs to be adjusted manually.
As indicated by ‘IS’ in the lens’ title, it has image stabilisation built-in. This is claimed to give up to 5 stops of shutter speed compensation by itself, or 6 stops when the lens is mounted on a Canon R-series camera, such as the Canon EOS R5 or EOS R6 II, with in-body image stabilisation (IBIS).
Canon has also given the lens RF 10-20mm f/4 L IS STM Peripheral Control Image Stabiliser, which is a new algorithm for wide-angle lenses that corrects peripheral motion blur. In essence, the algorithm calculates the degree of movement at the centre of the frame and then uses lens and camera stabilisation systems to correct the distortion and blur often seen around the edges with very wide lenses in video or stills.
A key benefit of the RF lens mount is that the Canon RF 10-20mm f/4 L IS STM is smaller and lighter than the EF 11-24mm f/4 L USM. In fact, it weighs just 570g, making it 610g lighter than the older lens. And at 83.7 x 111mm, it’s 20mm shorter than the EF 11-24mm f/4 L USM.
Naturally, being such a wide lens, the RF 10-20mm f/4 L IS STM isn’t designed to accept screw-on filters but has a gelatine filter holder behind the rear element.
As you’d expect with a Canon L-series lens, the RF 10-20mm f/4 L IS STM is dust and water-resistant.
![Canon RF 10-20mm f/4 L IS STM on Canon R5](https://b826082.smushcdn.com/826082/wp-content/uploads/2023/10/Canon-RF-10-20mm-f_4-L-IS-STM-0A_DSC2917-©ANicholson.jpg?lossy=2&strip=1&webp=1)
Canon RF 10-20mm f/4 L IS STM price and availability
The Canon RF 10-20mm f/4 L IS STM is priced at £2579.99 / $2,299 / €2929.99 and will go onsale in October 2023.
Specification
- Product type: Ultra-wide lens
- Announced: 11th October 2023
- Mount: Canon RF
- Format: Full-frame
- Focal length: 10-20mm
- Maximum aperture: f/22
- Minimum aperture: f/4
- Construction: 16 elements in 12 groups, including glass-moulded aspherical, UD (ultra-low dispersion) and Super UD glass elements
- Focusing system: STM
- Minimum focus distance: 25cm
- Maximum Magnification: 10mm: 0.06x, 20mm: 0.12x
- Stabilisation: Yes, up to 5 stops by itself of 6 stops on a camera with IBIS (in-body image stabilisation)
- Filter size: n/a – rear gelatine filters
- Weight: 570g
- Diameter x length (extension from lens mount): 83.7 x 111mm