Samyang Rokinon 20mm f/1.8 ED AS UMC Lens for Nikon F Review

The Samyang 20mm f/1.8 delivers pro-level sharpness at a budget price, but its autofocus can't keep up with fast action. A great pick for deliberate shooters.

Focal Length 20mm
Max Aperture f/1.8
Mount Nikon F
Stabilization No
Weather Sealed No
Weight 485 g
Samyang Rokinon 20mm f/1.8 ED AS UMC Lens for Nikon F lens
73.2 Overall Score

Overview

So you're looking at a 20mm f/1.8 prime lens for your Nikon F-mount camera. That's a pretty specific tool. It's a wide-angle lens, but that fast f/1.8 aperture makes it interesting for more than just landscapes. You get a field of view that's great for environmental portraits, tight interiors, or dramatic astrophotography where you want to pull in a lot of sky.

This lens sits in a bit of a niche. It's not the ultra-wide 14mm you'd take solely for architecture, and it's not the standard 35mm or 50mm most people grab for everyday shooting. At 20mm, it's a creative choice. The f/1.8 maximum aperture is the real headline here, promising solid low-light performance and the ability to throw backgrounds out of focus, which is less common for such a wide lens.

Who is it for? Think of the photographer who already has a standard zoom covered but wants a dedicated, fast wide-angle for specific scenarios. Maybe you shoot indoor events and need that extra stop of light. Or you're into the night sky and want a wide lens that can gather a lot of light quickly. It's a specialist, not a generalist.

Performance

The numbers tell a clear story. Its optical performance lands in the 83rd percentile, which is genuinely impressive for a lens at this price. That means sharpness and clarity are strong suits right out of the gate. The aperture score is in the 76th percentile, confirming that f/1.8 is a meaningful advantage over the typical f/2.8 or f/4 zooms in this focal range. In practice, that translates to being able to shoot in darker cafes or at dusk without cranking your ISO into noisy territory.

But the specs also show where compromises were made. Autofocus performance is down in the 49th percentile. Don't expect lightning-fast, silent tracking for sports or wildlife. It'll be fine for slower, more deliberate work, but it's not the lens's strength. There's also no image stabilization (43rd percentile), so you'll need to rely on good handheld technique or a tripod, especially in lower light when you can't use a fast shutter speed. The optical quality is the star, but the supporting features are basic.

Performance Percentiles

AF 46.3
Bokeh 68.2
Build 71.9
Macro 74
Optical 83.9
Aperture 75.7
Versatility 38.3
Social Proof 55.3
Stabilization 37.7

Pros & Cons

Pros

  • Strong optical (83th percentile) 84th
  • Strong macro (80th percentile) 76th
  • Strong aperture (76th percentile) 74th
  • Strong build (71th percentile) 72th

Cons

Specifications

Full Specifications

Optics

Focal Length Min 20
Focal Length Max 20
Elements 13
Groups 12

Aperture

Max Aperture f/1.8
Min Aperture f/22
Diaphragm Blades 7

Build

Mount Nikon F
Format Full-Frame
Weight 0.5 kg / 1.1 lbs
Filter Thread 77

AF & Stabilization

Stabilization No

Focus

Min Focus Distance 200

Value & Pricing

At around $399, the value proposition is all about trading features for optical quality. You're not paying for snappy autofocus, stabilization, or weather sealing. You're paying for a very good glass formula in a robust metal barrel. Compared to a Nikon-branded 20mm f/1.8, you're saving a significant chunk of change while getting remarkably close in pure image quality. The trade-off is in the autofocus performance and overall polish.

It's a classic 'third-party lens' deal. You get 90% of the image for 60% of the price, but you give up some of the seamless integration and extra features. If your budget is tight and your priority is image sharpness and that f/1.8 aperture, this lens makes a lot of sense.

Price History

$394 $396 $398 $400 $402 $404 Mar 1Mar 16 $399

vs Competition

Let's stack it up against some obvious alternatives. First, the Nikon AF-S 20mm f/1.8G. It's the direct competitor. The Nikon will have faster, quieter autofocus, better weather sealing, and arguably slightly better color rendering. But it costs almost twice as much. The Samyang gets you most of the way there optically for much less.

Then there's the zoom lens route, like a 14-24mm f/2.8 or 16-35mm f/4. These give you flexibility and often better build quality and AF, but they're bigger, heavier, and don't have that f/1.8 aperture. If you need the speed for astro or indoor work, the prime wins. Finally, consider a 24mm or 35mm prime instead. They're more versatile 'normal' wide angles, but they won't give you that expansive 20mm view. This lens is for when you specifically want that 20mm perspective with a bright aperture.

Spec Samyang Rokinon 20mm f/1.8 ED AS UMC Lens for Nikon F Tamron Tamron Di III Tamron 17-70mm f/2.8 Di III-A VC RXD Lens for Sony Meike Meike 55mm F1.4 Standard Aperture APS-C Frame AF Canon Canon RF 24mm f/1.8 Macro IS STM Lens Nikon Nikon NIKKOR Z DX 16-50mm f/2.8 VR Lens (Nikon Z) Panasonic Panasonic LUMIX G Vario 14-140mm f/3.5-5.6 II
Focal Length 20mm 17-70mm 55mm 24mm 16-50mm 14-140mm
Max Aperture f/1.8 f/2.8 f/1.4 f/1.8 f/2.8 f/3.5
Mount Nikon F Sony E Mount Nikon Z Canon RF Nikon Z Micro Four Thirds
Stabilization false true true true true true
Weather Sealed false false false false false false
Weight (g) 485 544 281 269 329 27
AF Type Autofocus STM Autofocus Autofocus
Lens Type Zoom Zoom Zoom Telephoto

Verdict

If you're a Nikon shooter who knows you want a 20mm perspective and you prioritize image sharpness and a fast aperture over autofocus speed and portability, this Samyang lens is a fantastic buy. It's perfect for astrophotography, interior photography, or creative environmental portraits where you can take your time. The image quality you get for $399 is hard to beat.

However, if you need a lens for fast-paced events, video work where silent AF is key, or if you're often shooting in bad weather, you should save up for the Nikon version or look at a weather-sealed zoom. And if you're just building your kit and aren't sure about focal lengths, a more standard 35mm or 50mm prime is probably a better, more versatile first investment. This lens rewards a photographer with a specific plan for it.