Samyang/Rokinon 20mm f/1.8 ED AS UMC review

Some versions of the Samyang/Rokinon 20mm f/1.8 ED AS UMC full-frame ultra-wide-angle prime are smarter than others

Samyang/Rokinon 20mm f/1.8 ED AS UMC
(Image: © Samyang)

Digital Camera World Verdict

The combination of a 20mm focal length and fast f/1.8 aperture make this lens well suited to shooting everything from cramped interiors to rolling landscapes and the night sky. It’s a manual focus lens that’s available in a wide range of mount options, although only the Nikon F and Pentax K options feature built-in electronics, which can be a problem for other makes of camera. Handling and image quality are impressive in all respects, making the lens good value at the price.


  • +

    Good build quality

  • +

    Pleasing image quality

  • +

    Nice handling


  • -

    A ‘dumb lens’ in most mount options

  • -

    No autofocus

  • -

    Lacks any weather-seals

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The Samyang/Rokinon 20mm f/1.8 ED AS UMC is a full-frame compatible, ultra-wide-angle prime lens that’s available in a wide range of mounting options for both full-frame and crop-sensor cameras. As such, it gives a generous 94.8-degree angle of view on full-frame bodies (measured on the diagonal of the frame), 66.9 to 70.3 degrees with APS-C format cameras and a more restrictive 56.1 degrees for Micro Four Thirds. In most mount options, it’s a fully manual or ‘dumb’ lens, with no electronic communication with the camera body.


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Matthew Richards

Matthew Richards is a photographer and journalist who has spent years using and reviewing all manner of photo gear. He is Digital Camera World's principal lens reviewer – and has tested more primes and zooms than most people have had hot dinners! 

His expertise with equipment doesn’t end there, though. He is also an encyclopedia  when it comes to all manner of cameras, camera holsters and bags, flashguns, tripods and heads, printers, papers and inks, and just about anything imaging-related. 

In an earlier life he was a broadcast engineer at the BBC, as well as a former editor of PC Guide.