AF Micro Nikkor 70-180 mm f/4.5-5.6 D ED

The AF Micro Nikkor 70‑180 originally caught my attention when it was still being sold by Nikon, and I was still using Nikon DSLRs. I missed out on this lens at that time, because it was a bit expensive and a bit large, not popular with photographers outside Japan, and in addition I was not sure whether the AF Micro Nikkor 200 mm f/4 was a better alternative. I ended up choosing the Sigma 180 mm f/3.5 because its price and weight were more reasonable than the Micro Nikkor 200 mm and it reached 1x, which the 70‑180 did not do. The Sigma 180 mm turned out to be the sharpest lens in my possession at that time (sharper than the AF Micro Nikkor 60 mm f/2.8 and 105 mm f/2.8), so it was not a bad choice.

I subsequently switched from Nikon DSLRs to Micro 4/3 and Sony mirrorless, gradually sold all lenses in Nikon mount, and for over a decade I paid little thought to Nikon cameras and lenses. The Nikon 1 system was obviously (to me at least) nothing to take seriously. Earlier this year I went full circle by replacing my Sony mirrorless with a Nikon Z8. Since then I purchased a few Nikon legacy lenses to use on the Z8 via lens adapters, including a Micro Nikkor 105 mm f/2.8 G.

While Nikon AF‑S and AF‑P lenses provide AF when adapted to Z cameras via Nikon FTZ and FTZII adapters, lenses from the Nikon AF series, including the 70‑180 mm, work only in manual focus with these lens adapters on Z cameras. On the other hand, AF‑series lenses do have an internal CPU, are automatically recognized by Z cameras when a Nikon FTZ or FTZ II adapter is used, are supported by in‑camera image stabilization, and their aperture is controlled by the camera. In other words, every AF‑series lens function is supported on Z cameras, except for autofocus.

MonsterAdapter markets an expensive lens adapter that contains a mechanical ("screwdriver") autofocus motor that, in principle, could allow AF-series lenses to autofocus on a Z camera. However, judging from reports by early users, this adapter is more an experimental device than a proven commercial product. At present, the high price and frequent technical problems of this adapter probably make the purchase of native Z lenses a better bet than attempting to use legacy mechanical‑autofocus Nikon F lenses on Z cameras (or alternatively, resigning oneself to use these lenses in manual focus only, and hoping for a more reliable future generation of adapters).

The Micro Nikkor 70‑180 remained the only true macro zoom lens. Many lenses have been marketed as so‑called "macro zooms", but they are in reality general‑purpose zooms with close focusing added as an afterthought, mainly as a selling point rather than actual performance. Most of the early "macro zooms" were consumer‑grade lenses, required the manual operation of a slider or ring to switch between normal and macro range, and in the macro range they did not perform much better than an ordinary lens with an add‑on lens slapped in front. Significant chromatic aberrations and curvature of field are common when these zoom lenses are used in their macro mode.

Modern zoom lenses are more honestly rated by their makers as lenses with close-up focus capabilities, perform better than the legacy "macro zooms", and continuously focus from infinity to their closest focus distances. The recently introduced Nikon Z 24‑105 mm f/4‑7.1, for example, reaches 0.5x in part of its range of focal lengths (70‑100 mm). However, unlike the 70‑180, the minimum focus distance of this 24‑105 varies with focal length.

The 70‑180 differs from all these lenses in being designed from the ground up to be used primarily as a macro and close‑up lens, and secondarily at higher distances. It focuses seamlessly between macro range and infinity. Like many other macro lenses, it works satisfactorily at higher distances and at infinity focus, but for this specific use there are other lenses designed for optimal performance.

Although the combination of capabilities of the 70‑180 remains unique, a few earlier lenses share with the 70‑180 a conceptually partly comparable design. This includes, for example, the Vivitar Series 1 90‑180 mm f/4.5 medical zoom from the mid‑1970s. In particular, the design of the 70‑180 built on the legacy of the Medical Nikkor 200 mm from the early 1960s and 120 mm from the early 1980s (see also below). The Medical Nikkors are not zoom lenses and use dedicated add‑on lenses to modify their native, quite limited, magnification ranges.

While the Medical Nikkors have a built‑in ring electronic flash with modeling light bulbs around the optics, which makes the barrel of these lenses very voluminous, the Vivitar 90‑180 and Micro Nikkor 70‑180 did away completely with built‑in light sources and add‑on lenses.

The maximum magnification of the 70‑180 changes with focal length. It reaches 0.75x at 180 mm, but only 0.31x at 70 mm. Thus, this lens does not reach the 1x magnification which today is regarded as a minimum for a true macro lens, but at 180 mm it is not far from 1x. On the other hand, for most of its focal length range it exceeds the 0.5x maximum magnification of several older Micro Nikkor lenses.

The zoom function of this lens can be very useful in close‑up and product photography, especially because in this lens zooming is coupled with parfocality and a constant effective aperture (see below). This eliminates the need to move the camera in order to change the framing of the subject, and largely eliminates the need to refocus after changing focal length. In spite of this, after zooming in, a small focus re‑adjustment may be required for bringing the exact focus onto the significant details of the subject.

A consequence of the constant effective aperture of this lens (see also below) is that the depth of field, with the 70‑180, decreases more rapidly than with traditional macro lenses when increasing the magnification (either by zooming in or by moving closer to the subject). Almost all traditional macro lenses increase their effective aperture when focusing closer. To change the behavior of the 70‑180, its lens aperture can be stopped down manually after focusing closer or increasing the focal length.

There is a common, but not universal, opinion that the 70‑180 is overall optically slightly better than the AF Micro Nikkor 200 mm f/4 D in the magnification range of the former lens. Quite possibly, there is a certain amount of confusion, in some of these opinions, between the older AI‑S Micro Nikkor 200 mm f/4 and the more modern AF Micro Nikkor 200 mm f/4 D. The AI‑S lens is known for its visible chromatic aberration in the macro range, which was largely corrected in the AF D model. The latter model, on the other hand, seems to be slightly worse than the AI‑S model when focused at higher distances.

When it comes to image sharpness in the part of the macro range accessible by the 70-180, the AF Micro Nikkor 200 mm f/4 D does have a moderate edge on the former lens, after accounting for the tricky comparison between the magnification‑dependent effective aperture of the 200 mm and the constant, magnification‑independent effective aperture of the 70-180.

This lens was launched in 1997 and produced until 2004. More than 90% of the second‑hand specimens world‑wide seem to be concentrated in Japan. During its production years, this lens was never popular in the West. For a few years after this lens was discontinued, its second‑hand price continued to increase, and around 2010 it peaked at almost twice the original price of a new lens. After the introduction of Nikon Z cameras, however, the price of the 70-180 dropped rapidly, probably because this lens can only be used in manual focus on Nikon Z cameras. Today, the price of a 70‑180 in good condition in Japan is around 250‑350 € (before import duties into the West), and in the EU 400‑500 €. US prices are somewhat intermediate.

The price of second-hand specimens of the Micro Nikkor 200 mm f/4 D has not decreased to the same extent as the 70‑180, and remains almost twice as much as the 70‑180.

Nikon published an article explaining some of the original thoughts behind the design of the 70‑180.

The AF Micro Nikkor 70‑180 in practice

Lens controls and indicators

The lens is equipped with four rings and a few additional controls. Any unusual characteristics of these controls are discussed in the following list. The implications of some of these features are discussed together with the optical scheme of the lens (see below). From front to rear:

• Focus ring. About half of the focus ring length, toward the rear of the lens, is covered in sculptured rubber. The front half is smooth. The plastic bayonet for attaching the lens shade is part of the focus ring, and therefore the lens shade rotates when manually focusing. An internal lens barrel sits flush within the bayonet of the lens shade when the lens is focused at infinity, but protrudes by 35 mm at the closest focus distance. Obviously, this not an internal focus lens. This internal barrel does not move when zooming. The total rotation of the focus ring is a little more than 180°.
• M/A ring. It selects manual focus or autofocus. A small chrome‑plated button must be kept pressed while rotating this ring. In manual focus mode, the focus ring is free to rotate, and the AF mechanical ("screwdriver") coupling to the AF motor in the camera body is disengaged. In autofocus mode, the focusing ring is locked in place. There is therefore no possibility to manually override AF, short of manually switching to M first. The M/A ring is made of plastic and is a known mechanical weakness in lenses of the late AF and AF‑D series. In used specimens, relatively frequently it is cracked around the chrome‑plated button, and once the crack reaches the edge of the ring, it is only a matter of time before the ring literally falls off in pieces. Nikon no longer repairs this particular fault. It is generally recommended to avoid purchasing second‑hand lenses with an incipient crack near the button of the A/F ring, even if very small.
• Immediately at the rear of the M/A ring is a Limit/Full slider for the focus limiter. The Limit position stops the rotation of the focus ring at a little less than 0.8 m focus distance. In this way, the range of focus distances is "broken" into a macro and a "normal" range of distances. The focus limiter is only useful in autofocus mode.
• A transparent plastic window displays the focus scale, graduated in ft (focus distance, printed in yellow), m (focus distance, printed in white), and, unusually, also m (working distance, i.e. the distance between subject and front edge of the lens barrel, printed in blue). The working distance is of paramount importance in the close‑up and macro ranges, but it is rare to see a working distance scale on a close‑up or macro lens. This is an example of the care with which the lens designers listened to the desires and needs of photographers when designing this particular lens.
• Zoom ring. Marked at 70, 85, 105, 135 and 180 mm. Note that the 70 is written in green, and the 180 in yellow. The meaning of this will be explained below. The total rotation of the zoom ring is less than 90°.
• Lens collar. The lens collar cannot be removed, and its foot is much too small by modern standards. It is, however, stiff enough to be used. I leave an Arca‑type plate permanently attached here, because it helps to support the lens weight with the palm of my left hand. The lens collar has no detents at any angle. The 0°, 90°, and -90° positions are indicated by small white dots. A small round knob offset to the left side locks the lens collar.
• Aperture ring. The aperture scale ranges from 4.5 to 32. Two index dots are present, one yellow and one green (see above). Nikon did this for a while to indicate that the aperture set with this ring changes a little (half a stop) while zooming. The aperture ring is locked at its fully closed position with a small slider when it is desired to let the camera control the lens aperture. For this to work on a Nikon Z camera, this lens must be mounted on an FTZ/FTZ II adapter. These adapters also allow the camera to communicate with the lens CPU, e.g. to let the lens automatically communicate to the camera the current focal length, which is required for in‑camera VR to work properly. With one of these adapters, a Z camera will also display the current aperture value of the lens, and allow the photographer to change it (usually with the secondary dial in A mode).

Lens aperture

Nikon macro lenses are among the few macro lenses that display the effective lens aperture, instead of the nominal aperture. On Micro Nikkor lenses except for the 70‑180, if you focus at infinity and f/4, then gradually focus closer, by the time you reach 1x the camera will tell you that the lens aperture is f/8. The 70‑180 radically changes this behavior: its effective aperture, as set either on the aperture ring or on the camera, remains constant across the whole focusing and zooming range (except for the small difference in lens speed when fully open). To do this, the nominal aperture of the lens must decrease when the lens focuses closer.

In practice, f/16 on this lens is effective f/16 and remains f/16 across the whole focus and zoom ranges. Well, almost: if you start at 70 mm focal length and f/4.5 and zoom to 180 mm, you will see the displayed aperture on the camera gradually change to f/5.6. If you start at 70 mm and f/5.6 or higher, on the other hand, the aperture remains the same across the whole zoom (and focus) range. This is also reflected in the two index dots of the aperture scale, one green (like the "40" marking on the zoom ring), the other yellow (like the "180" marking on the zoom ring), placed at a distance of half a stop from each other.

70‑180, teleconverters and add-on lenses

This lens does not accept teleconverters that require a cutout on the lens mount to accommodate an extra tab present on the front mount of the teleconverter. Early teleconverter models lacking both extra tab and protruding optics should be compatible with this lens. The rearmost optical subassembly of the 70‑180, housed in a relatively narrow barrel and a black light baffle slightly protruding at the rear of the optics, moves toward the rear of the lens when zooming toward shorter focal length, and stops just 3.5 mm from the rear of the lens mount. There is obviously no place for protruding teleconverter optics.

The user instructions of this lens say that the 70-180 is compatible with the Nikon TC-201 and TC-14A teleconverters, which in fact lack protruding optics.

A table in the user instructions says that this lens can use the Nikon close-up lens no. 5T or 6T, and provides the magnification range available with either lens, Nikon extension tubes, and Nikon bellows. The use of stacked 5T and 6T is explicitly not recommended by Nikon.

Lens design

When Nikon tasked its lens designers with creating a "different", true macro zoom lens, the designers solved the problem with a brilliant and simple solution: they designed a macro lens, then a zoom focal length multiplier, and finally they stuck the lens in front of the zoom focal length multiplier. Many of the peculiarities of this lens are explained by this conceptual design. Among other things, this explains why the front of the lens (i.e., the macro‑lens part) extends with focusing, and the rearmost optical subassembly, which is part of the zoom focal length multiplier, extends toward the rear of the lens barrel when zooming (it has nowhere else to go). It also explains how they achieved parfocality when zooming (the macro lens at the front does not change its focus when the focal length multiplier is zoomed). Finally, it explains why this lens is so long: 165 mm barrel length at infinity, which added to the 46.5 mm registration distance makes 211.5 mm ‑ apparently excessive for a lens with a maximum 180 mm focal length, unless one knows why.

The optical scheme uses in total 18 elements in 14 groups, mounted in 4 optical sub-assemblies. One element is made from ED glass. This optical scheme is discussed in US patent n. 5,717,527.

An optical-bench simulation of this lens is available on photonstophotos.net. The simulation displays in total 6 different combinations of focus and zoom settings. It shows that focus is achieved by moving a front optical subassembly of 5 optical elements as a whole, while 4 more elements at the rear of the moving subassembly remain immobile. The zoom part of the lens consists of two additional subassemblies, the first of three elements and the second of 6 elements, and the lens diaphragm attached immediately in front of the second of these subassemblies. Both of the zoom subassemblies move, in opposite directions, when zooming.

In principle, a variable focal length multiplier should change the lens speed by a variable amount. To keep the effective aperture constant, an aperture adjustment coupled to the zoom ring may be necessary. This is feasible, since the lens aperture is part of the focal length multiplier part (not of the macro lens part, which has no aperture control). I do not know in detail, however, how the lens designers solved this problem in practice. The fact that the front subassembly of the zoom comes almost into contact with the rear of the fixed macro subassemby, but has a smaller diameter than the latter, may be a part of this solution.

The lens speed is the last detail, and this is where the designers finally relented and compromised a little. The lens speed (and hence its effective aperture) does remain constant, except with the aperture fully open. At this point, the size of the front optical elements constrains the lens speed by half a stop at the maximum focal length.

The Medical Nikkor 120 mm is an earlier lens that shares a simpler, but conceptually related, optical design with the 70‑180. In particular, Nikon discussed here the design of the Medical Nikkor 120, which like the 70-180 consists of separate macro (at the front) and zoom (at the rear) parts. The zoom part, however, in the Medical Nikkor 120 is only used for focusing, while the macro part is a 3‑element fixed‑focus design (except for accepting dedicated add‑on lenses to change the focusing and magnification range).

The even older Medical Nikkor 200 mm is optically much simpler than its 120 mm successor. Both Medical Nikkors remain interesting as early examples of special-purpose macro lenses and as collector's items, but are hardly of any practical use today, especially the 200 mm.

The external appearance is part of the lens design. The wrinkled black paint finish of the 70-180 adds to the impression of weight and "class". Quite a few external details of this lens are made of plastic, but most of them are painted to look the same as the metal parts. There is no doubt that Nikon intended this lens, together with the AF Micro Nikkor 200 mm f/4, to look better than average, and at the same time to comply with already established external details present in many other Nikon lens models. Compared to these lenses, other AF- and AF-S series Micro Nikkors in polycarbonate external barrels look plasticky and cheaply made.

Weather sealing

This lens is not weather‑sealed. It should never be exposed to rain, drizzle, excessive humidity, salt spray, fine dust, and sand. Focusing does pump ambient air in and out of the lens barrel. The internal lens barrel at the front of the lens, which extends when focusing, slides within a felt‑lined outer barrel (which is actually part of the focus ring). I hate to think what a few hard grains of sand would cause, if lodged in that felt lining.

Perhaps the felt lining is not such a bad idea, considering the critical damage that sand would cause if left free to reach the internal helicoids and sliders. When this lens was designed (around 1995), Nikon did not have an extensive experience with weather sealing, and a felt lining could have been an obvious way to keep foreign particles out of the lens mechanisms, and at the same time prevent wear on painted surfaces sliding past each other.

Size and weight

Weight of this lens is a hefty 795 g. Externally, the lens is 165 mm long from filter mount to mounting flange when focused at infinity, with a diameter of the focus ring of 75.5 mm. The filter mount is 62 mm. This is a large and, especially, long lens, much more than its focal length range suggests.

Place of manufacture, serial number, and manufactured units

My second‑hand specimen of the lens, which I purchased from a German second‑hand camera business via eBay, was made in Japan, including also its lens shade, front cap, and rear cap. The serial number (on the side of the aperture ring) is 216263. Serial numbers of this lens started at 200001, according to the unofficial database of Nikon serial numbers. According to this source, in total Nikon produced at least 18,521 specimens of this lens, a relatively low number. My specimen should be among the last 2,500 produced, roughly between 2000 and 2004.

Lens shade, front cap and filter mount

The HB‑14 lens shade that comes with the 70‑180 is just wide enough to fit onto the front of the lens barrel in reversed orientation. In this orientation, just enough of the rubber-coated focusing ring remains accessible to allow manual focusing without removing the lens shade.

The lens shade mounts onto the lens with enough friction not to accidentally fall off unless handled roughly, but it does not "snap" into place with a positive tactile feedback.

As mentioned above, the lens shade attaches at the front of the focus ring and rotates with the latter. When the front of the lens extends, it does so within the lens shade, so in practice the lens shade shortens as the lens focuses closer. By the time focus reaches the closest distance, the lens shade is reduced to a length of just 7.5 mm in front of the filter mount, and very unlikely to interfere with the subject or its illumination.

The front cap is perhaps a little too old to originally have come with this lens. After 2000, Nikon was already using butterfly caps. On the other hand, this old type of lens cap accompanies also the AF Micro Nikkor 200 mm f/4 D.

A problem with this old-style cap is that it cannot be taken off while the lens shade is mounted in forward orientation. Butterfly caps can, and for this reason I replaced the cap shown above with a Nikon butterfly cap I already had.

The filter mount of the 70‑180 is 62 mm, at present a common size. The filter thread is located at the end of the internal, extending lens barrel, and does not rotate when focusing or zooming.

Working distance and magnification

The minimum working distance is 120 mm (excluding the lens shade). This produces a 0.31x magnification at 70 mm focal length, which increases to 0.75x at 180 mm. With this lens, therefore, the highest focal length also provides the maximum magnification. It is often the opposite in ordinary zoom lenses with close focusing capabilities.

Actual focal length

The actual focal length of the 70-180 strongly decreases when the lens is focused at closer distances. When the lens is set to its closest focus distance, with the zoom set to 180 mm, the actual focal length is approximately 90 mm.

Alternatives to the 70‑180

There are no exact alternatives among lenses for Nikon F and Nikon Z cameras. Some of the Z lenses are capable of a close focus almost equivalent to the 70‑180, but do not duplicate all the capabilities of the latter lens.

The Micro Nikkor 200 mm f/4 D in F mount exceeds the macro capabilities of the 70‑180 by focusing continuously from infinity to 1x. However, a 200 mm prime lens, although very useful in some circumstances, is not as versatile as a 70‑180 mm true macro zoom. Also the 200 mm operates only in manual focus when adapted to Z cameras. Incidentally, the effective focal length of the 200 mm lens is around 140 mm at 1x, with an effective lens speed of f/5.3 at 1x.

Laowa recently introduced an affordable 180 mm f/4.5 macro lens, available in an autofocus version for Nikon Z cameras. It manually focuses continuously between infinity and 1.5x, and when released was capable of autofocus only on distant subjects (mostly in the landscape range of focus). A firmware upgrade became available to use the same, small autofocus range for focus bracketing in the macro range. Users have reported that this range is barely sufficient to generate a focus‑bracketed sequence of 24 to 30 shots (depending on the step size). This is not enough for "deep" focus‑bracketed sequences of three‑dimensional subjects at magnifications around 0.75x‑1.5x, which require at a minimum several tens of images. In addition, functions that are useful in this context and commonly supported by cameras, like automatic return to the start focus position after the end of a sequence, do not seem to work with this lens. Nikon Z cameras only support this function with native Z lenses (Nikon AF-S lenses on Nikon FTZ/FTZ II adapters are not supported), so it is not surprising that this function does not work with a third-party lens.

In conclusion, the Laowa 180 mm is an interesting lens for single‑shot imaging, but too limited in automated stacking/bracketing capabilities. These capabilities were apparently added as an afterthought very late in the product development, or entirely after its launch. I decided to pass up on this lens and wait for lenses with better hardware support for deeper stacks. In the mean time, I continue to use motorized micrometric rails, focus racks and photomacroscopes in the lab, which support practically unlimited focus bracketing when driven by hardware controllers like the StackShot. My adapted Micro Nikkor 105 mm f/2.8 G does support a basic in‑camera focus‑bracketing on the Z8 (lacking some functionality like automatic return to the start position), sufficient for work on location when carrying a stand with motorized rail is not practical.

70‑180 tests on the web

Since this lens has already been tested quantitatively on at least a couple of other photography sites, I am not going to repeat these tests. You can see them at the following URLs:

• photographylife.com
• OpticaLimits

Conclusions

The AF Micro Nikkor 70‑180 mm f/4.5‑5.6 D, discontinued in 2004, is today reasonably priced on the second‑hand market, optically quite good, and works with camera‑controlled aperture, in‑camera VR automatically set to the proper lens focal length, and electronic connection between camera and in‑lens CPU, on a Nikon Z camera when paired to an FTZ or FTZ II lens adapter.

This lens is parfocal when zooming. It is designed from the ground up as a close-up and macro lens with zoom capability.

The effective aperture of this lens remains constant from infinity focus to maximum magnification, with the exception of the interval between f/4.5 (the fastest aperture at 70 mm) and f/5.6 (the fastest aperture at 180 mm).

The Micro Nikkor 70‑180 works only in manual focus when mounted via a lens adapter on a Nikon Z camera. Autofocus in itself is not very useful in a macro lens, but it means that in-camera focus bracketing is not possible with this lens on a Z camera.

The original HB‑14 lens shade is proportionate to the lens, and the front of the lens extends within the lens shade when focusing closer. In practice, this gradually reduces the depth of the lens shade at decreasing focus distance, which largely eliminates the risk of the lens shade interfering with the subject or its illumination.

This lens is not weather sealed. Its extending front barrel and lack of weather seals make it potentially vulnerable to water, moisture, salt spray, dust and sand.

Optical performance of this lens is still good by today's standards. No other lens, past or present, offers the same combination of features.