Review: AF NIKKOR 20mm f/2.8D

Let me start out by saying that this lens is not really designed for digital cameras. Oh sure, like most Nikon F-Mount lenses, it will fit and function as it should. But digital camera sensors behave differently than film with wide angle lenses.

That said, a one to one comparison between this lens and the same focal length in a lens optimized for digital sensors yielded amazingly similar results. So similar in fact that I would not hesitate recommending it for use with digital cameras. It is in fact already one of my favorite lenses.

This is a wonderful lens. It has the distinction of being one of Nikon’s smallest and lightest auto focus lenses. But what really makes it a standout is its versatility. On a DX SLR, it’s a great “street” lens with a focal length of 30mm. On an FX or 35mm SLR, it’s a fast, super-wide. When reversed, it becomes a high-power macro lens, afforded in part by its aperture ring. That aperture ring makes it compatible with the widest possible range of manual, AE, AF and Digital SLRs, and features an f/22 lock for use with electronic aperture control cameras. It’s a full-featured lens, with a hyperfocal scale and infrared focus indicator.

Of all my lens purchases, this had been the most difficult. I weighed the test reports against the personal reviews. I compared sample images. And finally, in desperation, I took a leap of faith and ordered it. Some lenses are like classic cars. They’re not at the top of the scale for performance, and they have their share of quirks, yet we love them. This is that kind of lens. For each of it’s idiosyncrasies, it has an upside that makes it a joy to use.

Build Quality ★★★★★
Solid, professional-grade, with a dull-chromed brass mount. Etched metal focusing ring, beneath the usual AF window. Non-brassing plastic exterior casing. At 9.5 oz. (266g) it has a nice heft, without being overly heavy, but it does weight in more than either the AF-S Nikkor 35mm at 7.0 oz. (198g) or the Voigtländer Ultron 40mm at 6.3 oz (180g).

Compatibility ★★★★★
Like all AF-D lenses, auto focus is not available on budget cameras such as the D40, D60, D3000, or D3100. However, the  viewfinder focus confirmation light functions perfectly, and full metering capability is retained.

Focusing ★★★★★
This lens works equally well as a manual or auto focus lens. Typical of wide-angle lenses, auto focus is practically unecessary due to its wide depth of field. You can easily estimate the distance and set it on the hyper focal scale with as good or better results than by using auto focus. When you do use auto focus mode, it’s a little noisier than that an AF-S lens would be, but in manual focus mode, it feels much more like a traditional manual focus lens. The direct-coupled focus ring is silky-smooth, although undamped, and its classic distance of rotation makes focusing easy.

Optical Quality ★★★
Optical quality will likely vary depending on the sensor, a characteristic of legacy wide angle lenses. Generally speaking, at f/2.8 sharpness is about the same for the center and the borders. Center sharpness peaks at f/5.6, and border sharpness peaks at f/8 where the center falls off just slightly. Chromatic aberrations at the border are on the high side and consistent throughout the range, being just slightly lower at f/2.8. With a field of view this wide, so much information is captured within the frame that the resolving capabilities are deceptive. Close inspection of pixels may leave you unimpressed, but you must keep in mind that everything you see is a substantial reduction in scale of your normal field of view. When viewed at the intended size, the sharpness and clarity are quite impressive. The only better performer would be the much larger AF-S Zoom-NIKKOR 17-35mm f/2.8D IF-ED at over three times the price. So, shoot it at f/5.6 when you can, f/2.8 when you must.

Value ★★★★
If like me, you own or plan on buying an FX or 35mm body, this lens is a great value due to its versatility. If you plan to stay with the DX format, a G lens such as the incredibly economical AF-S 18-55mm f/3.5-5.6ED VR kit lens might offer more value for your dollar.

Diaphragm
7 straight blades

Filters
Accepts 62mm filters. The Hoya Pro1 Digital MC UV(0) is highly recommended.

Hood
The HB-4, round bayonet hood is available as an optional accessory. If you prefer a petal-shaped hood, the Pearstone BQ1110 snap-on is an excellent option. However, thank to Nikon’s SIC (Super Integrated Coating) its high resistance to ghosting make a hood unnecessary for most purposes.

Specifications
You can view Nikon’s Specifications for this lens by visiting their website.

History
The design of this lens is based on the classic NIKKOR 20mm f/2.8 AI-S first manufactured in 1984, and still made today. In 1989, it was updated to the AF-NIKKOR 20mm f/2.8, and in 1994 distance coupling was added to create the AF-NIKKOR 20mm f/2.8D. The optics are identical in all three versions, and this latest version retains the etched metal focusing ring, visible behind the focus scale window typical of AF lenses.

Unfortunately, the market for wide primes is so small that it’s more likely that advances in sensor design will improve performance with existing lenses than new ones will be introduced. Today’s super-wide zooms are far superior to the primes of the past, at the cost of additional size and weight. So, it’s a safe bet this is the last super-wide prime that Nikon will produce, adding to its value.