AF Nikkor 14 mm f/2.8 D ED Aspheric RF

This page discusses the Nikon AF Nikkor 14 mm f/2.8 D ED Aspheric RF, introduced in 1999 and discontinued in 2020. No AF-S model of this prime lens was ever introduced. Its only successor is the AF‑S Nikkor 14‑24mm f/2.8 G ED zoom.

I am gradually switching from Micro 4/3 to full-frame Nikon Z, and in the process I have acquired a few legacy lenses from the Nikon AF and AF‑S series in F mount, to use on my Z8 via an FTZ or FTZ II adapter. AF-series lenses are electronically recognized by the Z8 when mounted on an FTZ/FTZ II adapter, work well with in-camera VR, focus peaking etc., but unlike the AF-S lenses they do not provide autofocus (and anything else that relies on AF, like focus bracketing) with these adapters. Probably for this reason, AF-series lenses are often available at reasonable prices on the second-hand market.

Monster Adapter markets an expensive F to Z adapter that brings autofocus to AF-series lenses on Z cameras. However, numerous owners of this adapter complain of erratic or non‑functioning AF with a variety of Nikon F and third‑party lenses. I regard this adapter as an interesting idea, but not mature enough for the consumer market. Besides, there may be valid technical reasons why Nikon decided not to offer this type of adapter.

Lenses from the AF series are often significantly smaller than their AF‑S counterparts. In the particular case of extreme wideangles, I don't regard the lack of autofocus of AF lenses with FTZ/FTZ II adapters as a significant handicap, since I don't tend to use tese lenses in a hurry or with fast-moving subjects.

A Nikkor Z 14‑24 mm f/2.8 S is available, but it is physically large and costs five times what I paid for my second-hand specimen of the 14 mm F prime. Even if I should decide to bear the cost of this Z lens, there is a real risk that I would end up leaving it at home on a trip abroad or a long excursion, because of its size and weight. This is exactly what is happening with my Olympus 7‑14 mm f/2.8 Pro, and for this reason I just sold this lens.

The AF‑S Nikkor 14‑24 mm f/2.8 on an FTZ adapter is bigger and much heavier than the Z 14‑24, so this AF‑S zoom is not an alternative for me.

In practice, so far I have used the Olympus 7‑14 most of the time at 7 mm, and occasionally around 10 to 12 mm. Therefore, as a zoom, it has not been much more useful to me than a 14 mm prime lens. Its zoom range overlaps at the long end with the 12‑40 mm f/2.8 Pro, which is my all‑round lens on Micro 4/3. I prefer the 12‑40 to the 7‑14 for shooting in the 12‑14 mm zoom range, because the 12-40 is less vulnerable to flare. The same thing applies to my Nikkor Z 24-120 mm f/4 S, which is my all‑round lens for the Z8 and eliminates the need for a 24 mm prime.

I already own the excellent AF Nikkor 20 mm f/2.8 for use with my Z8, as well as an AI 24 mm f/2.8 that I have been using for years in UV and IR imaging on a modified Sony mirrorless. All three lenses can share a single FTZ adapter to mount on Nikon Z cameras. I used the 24 mm for the tests discussed below.

When I need to reduce the weight of my camera backpack, I can choose to leave at home either the 14 mm or 20 mm, depending on which of these lenses I regard as more superfluous for a given trip. The 20 mm is particularly weight‑saving, compared to the 14 mm (278 g versus 670 g), so I may leave the 14 mm at home if I need to shave weight from my backpack on a long trip, unless I know in advance that scenic photography will require its wider view. A Nikkor AF‑S 14‑24 or Z 14‑24 zoom would not give me this option.

On full frame, the AF Nikkor 14 mm and 20 mm are equivalent in field of view to the Olympus 7‑14 at 7 mm and 10 mm, respectively, on Micro 4/3.

The 14 mm can be found used on eBay, but it is not as common as the AF 20 mm and AI 24 mm. When I looked for a 14 mm to purchase, there were no more than two or three specimens available in the EU. Other legacy Nikkor F wideangles, including the AI‑S 15 mm f/3.5, are far more common (possibly because they are harder to sell). On eBay, prices of the 14 mm vary roughly between 350 and 450 € in the EU, depending on the lens condition. I have seen occasional fantasy prices for this lens approaching 1,000 €.

Multiple online reviews agree that the 14 mm is one of the best Nikon ultra‑wideangle primes, e.g., Optical Limits, alexluyckx.com, kenrockwell.com, philipreeve.net. Other photographers express a less rosy opinion of this lens. The remarkably high price of this lens at the time it was marketed by Nikon may be one of the reasons for higher‑than‑average expectations from some of its users.

Features

The 14 mm is a relatively large lens. Its size is 87 by 87 mm, and the weight a relatively hefty 670 g. Placed side‑by‑side with the AF 20 mm f/2.8 and AI‑S 24 mm f/2.8 (Figure 1 above), it is quite bulky, and the front element much larger than in the two other lenses. On the other hand, the 14 mm is not so different from the Olympus 7‑14 mm. Note how the 14 mm and the Olympus lens share a large and bulging front element.

 

The lens shade of the 14 mm is an integral part of the lens barrel and cannot be removed. The effectiveness of the petal lens shade of the 14 mm is limited, as expected from the bulging shape of the front element. The left hand of the photographer can be used as a flag to block out the sun when necessary (while carefully checking the viewfinder for stray fingers).

The diagonal angle of view is 114° (104° horizontal, 81° vertical).

Note the reflection of the photographer holding the camera on the internal elements of the lens in the above figure.

This lens can be used on APS‑C cameras (both DSLRs and Z mirrorless), but on this format it is equivalent in field of view to a 21 mm on full frame. On these cameras, a DX wideangle lens (not necessarily Nikon) can save money, weight and space.

The above figure shows the optical scheme of the 14 mm. This lens uses 14 elements in 12 groups, with two hybrid‑aspheric elements and one ED. The aspheric elements are shown in blue in the above figure, the ED element in yellow. A hybrid, or compound, aspheric lens is made by cementing a precision‑molded, thin plastic lens with one aspheric surface onto an ordinary, spheric glass lens. This is much cheaper than grinding an aspheric lens from a glass blank.

Rumors are that this lens was actually manufactured for Nikon by Tamron. There is a Tamron‑branded legacy lens of the right age with the same specifications, said to have worse coatings than the Nikon‑branded version and externally looking rather uninspiring. The Tamron version uses the same two hybrid‑aspheric elements, but possibly lacks an ED element.

The front element of the 14 mm is very bulbous, and barely contained within the lens shade. Attention must be paid not to accidentally touch it when handling the lens, or bumping it against obstacles while carrying the camera. The photographer must learn to avoid placing any part of the left hand on the outside of the lens shade when supporting the lens.

A proprietary leather front lens cap accompanies the lens and slides onto the lens shade. This lens cap is commonly worn out, sometimes shedding abundant faux leather dust, other times sticky to the touch (mine is the latter case).

A suitable rigid front lens cap replacement can be made by 3D printing. I suggest this one from Thingiverse. A few Chinese sellers offer 3D‑printed replacement caps of unknown quality and simpler design. Rubber and neoprene caps of the right size can be found, but these materials are too flexible for this use, and can easily be pushed into contact with the front optical element while handling the lens or carrying it in a backpack. These lens caps are usually printed in PLA plastic, but I printed mine in PETG plastic because of its higher stiffness and lesser tendency to sag and deform with time. I glued sections of the "fiber" side of Velcro ribbon inside the perimeter of the cap to increase friction of the cap against the lens.

This lens focuses by moving its rear optical subassembly (hence the "RF" name tag, meaning rear focusing). The front of the lens neither extends nor turns when focusing.

Unlike the AF 20 mm and AI 24 mm, this lens is adorned with a gold‑colored ring around the base of the lens shade, and a plastic tag with branding and lens model name in relief and gold‑painted, glued on the lens barrel. Among AF‑series lenses, this tag is generally found on "premium", often physically large lenses. On AF‑S lenses, a similar tag is ubiquitous and not indicative of premium quality.

A plastic control ring bearing a chrome‑plated button is used to switch between AF and MF. On the Z8 with FTZ adapter, this ring is always set to MF. The button must be pressed to unlock the ring. This type of ring is known to crack with time and use, and in the end may detach in pieces from the lens barrel. When purchasing a second‑hand lens equipped with this type of ring, make sure that it does not have incipient cracks, especially around the button or screw heads. Nikon used to replace a broken ring for a steep fee, but no longer does this.

A locking slider is present on the barrel near the aperture ring, and is used to lock the aperture ring at the f/22 setting. This allows control of the lens aperture by the camera, and metering with the aperture fully open. With the Z8, the aperture ring is always left locked, and the lens aperture changed with the camera controls.

The 14 mm lacks filter threads at its front, and instead can use a gel filter inserted into a filter carrier permanently attached at the rear of the lens, accessible only when the lens is detached from the camera. The exact shape and dimensions of the gel filters for the 14 mm are indicated in the user instructions for the lens. As far as I know, Nikon did not provide pre‑cut gel filters for this lens, and the photographer was expected to cut his own filters from larger sheets. The AF 20 mm and AI 24 mm, on the other hand, are equipped with front filter threads.

This lens is not weather sealed.

There are rumors that Nikon marketed two earlier versions of the 14 mm before this one, but I found no evidence for this. These rumors may actually refer to the two versions (AI and AI‑S) of the older 15 mm f/3.5. The "Aspherical" label, printed like an afterthought on the bottom of the lens barrel, half a turn away from the plastic tag bearing the official lens branding and model in gold color, could be one way to tell this model of the 14 mm from the fabled earlier ones, if they exist.

In most other AF‑series lenses, the label located in this position only says "Made in Japan", without any mention of lens features.

Because of its barrel diameter, and especially the fixed lens shade, this lens can be barely mounted on a Nikon FTZ adapter with an Arca plate attached at its bottom. However, the Arca plate and the bottom bulge of the FTZ are in the way of operating the lens controls, and it is better to use an FTZ II adapter.

Performance

Vignetting in the 14 mm is relatively strong, but the Z8 automatically corrects it when the lens is mounted on an FTZ/FTZ II adapter. Geometric distortion and transversal chromatic aberration are likewise automatically corrected in‑camera, sensor‑based VR is automatically configured with the correct lens data, and the lens is correctly identified in each picture's metadata. Software used to post-process raw images produced with this lens can read the metadata and automatically apply the correct lens profile to these images.

Stopping down to f/8 strongly reduces vignetting, coma and transversal chromatic aberration. 10‑point stars are well‑visible on strong point light sources in night‑time landscape pictures. Unavoidably, there is flare when sunlight directly strikes the large front element of the lens, and an even stronger flare if the sun is in the picture. On the other hand, I have yet to see a fast ultra‑wideangle truly immune to this problem.

Manual focus with the 14 mm is easy if focus peaking is enabled in the camera menu. One difference between Nikon F DSLRs and Z mirrorless is that DSLRs perform manual focus with the lens aperture fully open (f/2.8 in this case), while Z mirrorless cameras most of the time stop down the lens to f/5.6. A consequence is that depth of field in live view is higher on Z cameras than on DSLRs, and focus peaking is a little less discriminating. When I want to manually set a perfect focus, I may "fiddle" with the focus ring a couple of times, while looking in the viewfinder, to reach an optimal focus position based on focus peaking.

Tests

Figure 7 shows that there is a striking difference in field of view between 14 mm and 20 mm. These test shots were taken at f/5.6 with both lenses. The dark street at the bottom of the 14 mm shot is in the shadow of another building.

The 14 mm, given its very short focal length, is also more prone to the "wideangle rendering" when it is inclined even slightly up or down, or oblique to the subject's surface. This is not an optical aberration and has nothing to do with geometric distortion, although it is often confused with the latter by inexperienced photographers.

The "trick" for minimizing this rendering is simple: shoot buildings, standing people and trees while holding the camera perfectly horizontal, and perpendicular to the subject's surface in the case of buildings. Turn or move the camera sideways to frame the subject horizontally, but to frame it vertically only move the camera up or down, without tilting it from the horizontal. If possible, avoid placing people or trees near the sides of the frame. Shoot in portrait orientation and crop the picture in post‑processing if you cannot move the camera up or down by a sufficient amount to entirely capture the subject.

The distance scale is equipped with DOF marks for f/8, f/11 and f/16. These marks are only indicative, and too "optimistic" for use with a high‑megapixel camera like the Z8. In practice, the lens should be stopped down at least by one more full stop than suggested by the DOF scale.

The main usefulness of the DOF scale is in connection with parfocal shooting. In this technique, you set the focus distance and lens aperture so that the DOF interval ranges from the closest to the farthest point of interest, and shoot without focusing. Often, the farthest point of interest is at infinity.

Vignetting

The Z8 automatically corrects vignetting, based on the lens recognized by the camera. However, some vignetting remains even after this correction with both the 14 mm and 20 mm. In the above figure, vignetting is particularly visible in the sky. Residual vignetting is visible at f/2.8 to f/4 in both lenses, and essentially disappears at f/5.6 and above. The residual vignetting is high with the 20 mm at f/2.8. At this aperture, the 20 mm underexposes by roughly one stop on most of the frame, by 2-3 stops in the corners, and is free from vignetting only in the very center of the image. Vignetting is quite similar with the 20 mm at f/4 and 14 mm at f/2.8, so the 14 mm is the clear winner in this comparison.

The bottom dark area in the 14 mm pictures is not vignetting, it is a dark street where sunlight did not reach.

The 14 mm is quite blurry in the center of the frame at f/2.8. Stopping down to f/8 dramatically improves the image sharpness.

Halfway toward the left edge of the frame, at f/2.8 the resolution is almost as high as the 45.7 Mpixel Z8 can record. A difference like night and day between this and the center of the frame. Resolution of the same area at f/8 is as high as it gets.

At the extreme left edge of the frame, there is a moderate fuzziness at f/2.8, which gets better very quickly moving away from the edge. At f/8, the resolution is quite good right up to the edge of the frame.

The puzzling poor resolution of the 14 mm at f/2.8 in the center of the frame requires some thought. This is the first time I see a wideangle lens that, fully open, performs poorly in the center, then turns perfect halfway toward the edge, and finally becomes slightly worse at the edge. A first possibility to consider is that the lens may be unable to focus at infinity, and instead shoots slightly short of this. With the particular subject used for this test, the center of the frame is at a higher distance from the camera than the mid-regions. I shot these images with the focus ring turned all the way to infinity. I took another set of shots, and the result is the same. There is indeed a central circular fuzzy area approximately 1,100 pixels across. Further tests with different landscape subjects, all at infinity, show that this area remains fuzzy when the rest of the subject is in-focus and sharp.

I shot the above test image less than 1 m from the subject, with the lens cap placed at the center of the frame. I focused by magnifying the image in the viewfinder (not by using focus peaking, which in this case only picked up the outer edge of the lens cap). This shows that the lens is perfectly capable of producing a sharp image in the center of the frame, even when fully open at f/2.8, when the subject is located at a closer distance than infinity. The fuzziness observed in landscape pictures is therefore not caused by spherical aberration but by a complex curvature of field, with the center of the frame unfocused because the focusing helicoid does not retract by a sufficient amount (i.e. slightly past the infinity mark). The shape of the field of focus of the 14 mm on the sensor plane is therefore, in practice, approximately flat but with a rounded hump in its center. The aspheric elements may have something to do with this.

The simplest solution is to stop down this lens to f/8, at which point the increased depth-of-field completely hides the problem and eliminates the need to focus past infinity. In theory, servicing this lens in order to allow focusing slightly past infinity could eliminate the central blur already by stopping down to f/5.6, possibly f/4.

A theoretical solution that does not require shipping the lens to a camera repair shop is attaching a glass filter at the rear of the lens, e.g. by replacing the now useless gel filter carrier with a glass "protector" filter made from 1-2 mm thick glass. The result of this is to shorten the optical distance between lens and sensor, allowing the lens to focus slightly past infinity. Given the short focal length of the 14 mm, a decrease in optical length path of less than a mm should alter its infinity focus by a sufficient amount, without introducing significant aberrations. I will report here once I have tried this in practice.

This is an example of how understanding the behavior of a lens can be essential to obtain good results.

Alternatives

The older AI‑S 15 mm f/3.5 is optically worse than the 14 mm, in spite of commanding a higher second‑hand price than the 14 mm.

A natural alternative to the 14 mm among Nikkor F lenses is the AF‑S 14‑24 mm f/2.8 G ED, which is much larger, weighs substantially more, and costs between 100 and 200 € more than the 14 mm on the second‑hand market. This lens is sharper than the 14 mm.

The Z 14‑24 mm is even better and much lighter than the AF‑S zoom, but if its price is out of your reach and you need a sharper lens than the 14 mm, the AF‑S zoom may be the next‑best choice. The AF-S lens also provides autofocus when mounted on an FTZ adapter.

The legacy F‑mount AF Nikkor 18 mm f/2.8 D, in my opinion, is optically poorer than both the 14 and 20 mm. It is also too close to either lens to be a useful addition to my lens kit.

The legacy Nikkor 13 mm f/5.6 and the optically identical AI Nikkor 13 mm f/5.6 S are an old design, and their 16 elements in 12 groups, coupled with antiquated coatings, ensure plenty of flare and internal reflections.

The legacy AF Nikkor 16 mm f/2.8 full‑frame fisheye can be worth considering as an alternative to the 14 mm. I reviewed the 16 mm fisheye here. Coupled with de‑fishing in post‑processing, it is an interesting alternative to the 14 mm. The results are more closely comparable to a rectilinear 11-12 mm than a 14 mm if one can tolerate a moderate blurriness in the periphery. If cropped down from 45.7 Mpixel to approximately 36 Mpixel, it is at least as good as the 14 mm. The additional possibility of using it without de‑fishing (with or without cropping) adds a whole new layer of versatility, especially in natural landscapes. In my Micro 4/3 kit I did much the same thing, flanking the Olympus 7‑14 with the very small and very cheap Samyang 7.5 mm fisheye. This fisheye did give me a number of memorable shots (see also here).

The AF‑S Nikkor 8‑15mm f3.5‑4.5 zoom fisheye is not excessively large, and could be an alternative to the 16 mm fisheye for photographers who use both FX and DX cameras. The possibility of using it as a circular-image fisheye at 8 mm on full frame, in my opinion, is rarely useful. However, a slight zooming on DX makes it cover the whole DX frame including the corners, and full zooming to 15 mm covers the full frame sensor. For photographers using exclusively DX cameras, a third‑party APS-C fisheye like the Samyang 8 mm f/3.5 is far cheaper.

Conclusions

The AF Nikkor 14 mm f/2.8 D ED Aspheric RF performs reasonably well as an extreme wideangle on the Nikon Z8.

This lens is available on the second‑hand market but relatively uncommon, and is reasonably priced.

This lens cannot autofocus on the FTZ and FTZ II F‑to‑Z adapters. Parfocal focusing, a.k.a. zone focusing, without checking for focus on the LCD screen or in the viewfinder, is entirely practical with this lens because of its very high depth of field.

The depth‑of‑field marks on the lens barrel are better than in other Nikon wideangles, but a bit too "optimistic" on a high‑megapixel camera like the Z8. Stop down by one more stop than the depth‑of‑field marks say.

This lens is not weather sealed.

Manual focus is usually easy with this lens on the Z8 with focus peaking enabled.

My specimen of the 14 mm displays a complex type of field curvature, which makes it impossible to focus at infinity in the central portion of the frame because this would require focusing slightly past infinity (which this lens cannot do, unlike many modern lenses). The most feasible solution is to stop down to f/8, which causes DOF to hide the problem. I do not know whether other specimens of this lens display the same behavior.