Samyang / Rokinon AF 12mm F2.0 RF-S

The Samyang AF 12mm F2.0 RF-S is a fast autofocus ultra-wide prime for Canon RF-S (APS-C) mirrorless cameras. Samyang announced it in December 2024 as its first RF-S lens and calls it the widest angle in Canon's RF-S lineup. On a crop sensor, 12 mm corresponds to roughly 19 mm in full frame terms. It is aimed at landscape, architecture, astrophotography and travel shooters who want a small, bright wide angle.

Optical design

The lens has 12 elements in 10 groups. According to Samyang, three extra-low dispersion (ED) elements and two aspherical elements, one of them a hybrid aspherical (H-ASP), reduce chromatic aberration, distortion and sagittal coma, which matters for night skies. The coating is UMC, the aperture runs from F2 to F22 with seven blades, and the angle of view on APS-C is 96.8 degrees. Samyang points out that the seven blades produce a starburst effect on bright point lights.

Autofocus and handling

Focusing is driven by a Linear STM stepping motor that Samyang describes as silent and precise. A manual focus ring and an AF/MF switch on the barrel are fitted. The minimum focus distance is 20 cm at a maximum magnification of 0.09x, which allows close subjects with a strong wide-angle perspective. The specifications list no optical image stabilizer, so shake reduction depends on the camera body.

Build and size

The lens weighs 213 g, measures 57.2 mm in length and 70 mm in diameter and takes 62 mm filters. Samyang describes a matte finish with a red ring accent and states that the lens is weather sealed against dust, light rain and snow. It also points to good compatibility with tripods and gimbals.

Where it fits

For Canon RF-S users it sits between very compact ultra-wide zooms and brighter wide primes. The Canon RF-S 10-18mm F4.5-6.3 IS STM weighs 150 g and is stabilized, but more than two stops slower at the wide end. The Sigma 10-18mm F2.8 DC DN for RF offers a zoom range at F2.8 and weighs 260 g, and the Sigma 12mm F1.4 DC Contemporary is one stop faster at 250 g in its RF version.

Pros and cons

Pros

• Very wide angle with a bright F2 aperture for APS-C
• Light at 213 g and only 57.2 mm long
• Weather sealing and a physical AF/MF switch
• Close focusing at 20 cm
• Fast and quiet Linear STM autofocus according to Samyang

Cons

• No optical image stabilizer
• Fixed focal length, less flexible than a wide zoom
• Alternatives such as the Sigma 12mm F1.4 are one stop faster
• Made for RF-S bodies, not designed for full frame use

Verdict

The AF 12mm F2.0 RF-S gives Canon APS-C shooters a compact, light ultra-wide with a useful F2 aperture and weather sealing. It suits landscape, astro and travel work where size matters more than the last stop of light or a zoom range.