Nikon's New AF-S 20mm 1.8G Review

A Long Overdue Digital Update

It’s been 30 years since Nikon updated its 20mm f/2.8 wide-angle lens and this new version, announced in September along with the Nikon D750 and SB-500 Speedlight, is sharp and capable. The AF-S NIKKOR 20mm f/1.8G ED is priced around $799 and is optimized for Nikon’s FX digital imaging system. With that maximum aperture of f/1.8, it joins the elite company of other distinguished Nikon primes - the 28, 35, 50 and 85mm ED lenses. If you shoot architecture, astrophotography or landscapes, the nagging question becomes - is this a lens I need in my bag?

Initial Thoughts

With 13 elements in 11 groups, the 20mm is lightweight, ergonomically balanced and a real comfortable fit in the palm once connected to your camera. If you are accustomed to a wide-angle zoom, this lens seems downright stubby without the lens shade. At 12.5-ounces, this 1.8G ED lens is similar in size to my 50mm/1.4G and feels right at home among other prime G lenses in most small camera shoulder bags or backpacks. The HB-72 bayonet lens shade reverses on the lens barrel for a trim profile when packing for travel.

Ergonomics

If you shoot landscapes and favor outdoor photography as an interest, the 20mm functions as a lower cost alternative to the robust, yet heavy, 14-24mm/2.8ED or 16-35mm/4VR. Comparing a wide prime to wide zoom lenses is unfair but it’s important to really assess the ways in which this new 20mm differs in scale and feel to the 16-35mm and 14-24mm.  To keep it simple, the 20mm is lighter, smaller, more compact and significantly easier on the wallet with the tradeoff being that you are sacrificing the flexibility of multiple focal lengths offered by a zoom.

Unlike the 14-24mm, the 77mm thread on the polycarbonate barrel of the 20 makes it easy to attach a UV, polarizing filter or graduated neutral density filter system. Keep in mind that the quality of your circular polarizer matters as only thin, higher end glass will mitigate uneven polarization in the sky which can be more problematic in vertical rather than horizontal compositions. Given that many of Nikon’s key telephoto lenses (24-70mm and 70-200mm) utilize the 77mm thread, you will be able to seamlessly make use of your existing filter kit.

When shooting riverine scenes with the objective of long exposures in midday light, I often use a Singh Ray variable neutral density filter as it allows me to dial in two to eight stops of density and extend my shutter speed. I noticed that this filter, due to its thickness, caused a vignette in the corners along the right side of the frame (see sample image). This was really the only shortcoming that I experienced when out in the field with the 20mm but this is not an uncommon scenario with a thick filter. While there is slight fall off at 1.8, this shortcoming is minor relative to the overall performance of the lens at common apertures in the majority of shooting situations.

Performance

When mounted on an FX body, the 20mm offers 94-degrees of coverage and is the equivalent of 30mm and 70-degrees when mounted on a DX system. Chromatic aberration and distortion are minimal as a result of the ED (extra low dispersion) Nikon glass.

Whether you shoot stills or use Nikon’s DSLR systems for time lapse or video capture, the 20mm is sharp at capture with a quiet Silent Wave Motor that close focuses to an unexpected 7.8 inches. This quieting technology represents one of Nikon’s major updates relative to its ancestor, as the 20mm/2.8 AF seems clunky now in comparison.

A common option on most new Nikon lenses grants the user the option to manually override autofocus to tack up a shot. I found that autofocus was accurate for the majority of all of my shooting and rarely did I need to go manual. 

The Nano Crystal coat on the lens is highly successful at mitigating lens flare when capturing backlight scenarios or forcing a shot into the sun for creative effect. At its smallest aperture of F16, the seven interior blades render dramatic sunbursts with minimal flare (see sample image). When shooting at night or targeting long-exposure star photographs, the 20mm’s optical system portrays stars as pinpoints rather than tails, an indication of the lens’ excellent coma (comatic aberration) performance. This can be a critical nuance when targeting the North Star and working astrophotography.

Bottom Line – Would I Buy It?

A fixed 20mm lens is not a must-have essential piece for your camera bag but this new update from Nikon is an ideal, lightweight performer at an affordable price.  If you enjoy outdoor photography and often take your gear along for the adventure, the weight and size of this lens make it a must-have piece of glass.

Whether shooting stills or motion, it functions as a fast wide angle adept in a variety of contexts. It is right at home when capturing the entirety of a church from the overhead balcony during a wedding ceremony, working with long-exposures in astrophotography or layering content for a dramatic mountainous landscape. It’s truly an affordable and well-built professional grade offering from Nikon that is well worth it if you are looking to replace the older 20mm/2.8 or add a compact wide-angle lens to your existing arsenal. If you have the means, I’d go get it.

You might be interested in another user review on the 20mm f/1.8G AF-S FX Nikkor as well.

Sample images (Click the images for larger view)

More articles by Joseph Gamble

The 24-70mm/2.8G ED IF AF-S Nikkor Review

To Clean or Not To Clean Your Sensor

How to Digitize Your Slide Library with a Nikon FX DSLR

More...

More articles that might interest you

The 105mm f/2.8G ED IF AF-S VR Micro Nikkor Review

Nikkor AF 80-200mm/2.8D Review

Full Spectrum Cameras, Part III, UV Photography