Most photographers will have the urge to take macro images at some point. Yet buying a dedicated lens for this task can be expensive, which is why so many different tubes, adapters, coupling devices and screw-in lenses exist so standard lenses can be adapted for macro use.

This latest Nikon model, the AF-S DX Micro Nikkor 40mm f/2.8G, aims to provide an affordable solution to the problem for many entry-level and enthusiast photographers.

With a focal length similar to the 50mm standard lens, and a price of around £250, this macro optic could find its way into many kit bags.

Construction

The 40mm f/2.8 Nikkor lens is constructed of nine elements in seven groups and offers a 40mm focal length, which is equivalent to 60mm on a full-frame (FX) Nikon DSLR. Each aperture blade is rounded to create smooth, out-of-focus bokeh, and at infinity the aperture range is f/2.8 to f/22.

As you would expect for a lens costing around £250, the body itself is made of plastic – or polycarbonate, as manufacturers call it these days. The plastic has a slightly mottled texture that gives it a matt finish.

The body mount is made from metal, and despite the largely plastic construction of the lens it is well put together, with no wobble and a smooth focus mechanism.

The focus ring itself has a fairly slim rubber grip approximately 11mm wide, and sitting below this on the lens barrel is a focus distance chart. This shows the current focus distance in feet and metres, as well as the current level of reproduction, from 10:1 at around 40cm to 1:1 at the minimum focus distance of 16.3cm.

There is no optical image stabilisation in the lens, the presence of which would have no doubt significantly increased its size and price.

However, there are two switches on the side of the lens: one to switch between autofocus with manual override (M/A) and full manual focus; and the other to switch between using the full focus range or locking it between infinity and 20cm. This switch excludes the 16.3-20cm range from use, which constitutes a turn of around one-third of the barrel, compared to just a quarter turn to go from 20cm to infinity. Excluding the minimum focus range makes the lens faster to focus, allowing it to perform more like a standard 40mm fixed lens.

In comparison, the older 60mm f/2.8D AF Micro Nikkor FX lens also has a lock, but this one allows the focal range to be locked to either close focus or standard focus. This is more useful because it means the lens can perform either as a standard optic or purely for macro work, which makes AF focusing easier.

Handling

With its solid plastic construction and lack of an aperture ring, the 40mm f/2.8 Micro Nikkor feels like other, similar lenses in the company’s range, such as the AF-S Nikkor 50mm f/1.8G lens. The only change I would make to the physical design of the lens body would be a slightly wider rubber grip for the focus ring.

The modest size of the macro lens, its 60mm (equivalent) focal length and f/2.8 aperture make it a nice everyday lens for portrait and documentary images. However, if you specialise more in documentary images than macro photography, then the AF-S DX Nikkor 35mm f/1.8G lens may be a better option, and it is £100 cheaper.

As far as using the lens for its intended macro images, there are a few things potential users should be aware of. The first is that at the optic’s closest focus point, the lens movements reduce the amount of light reaching the image plane. Nikon DSLRs take this loss of light into account and report the aperture range at the minimum focal distance as f/4.2 to f/36.

However, it must be remembered that as far as calculating the depth of field is concerned, the nominal actual aperture should be used. So when the camera is quoting the lens aperture as f/36 for exposure purposes, remember that it is actually f/22 with regard to depth of field calculation.

Another, more important thing to remember when using the lens for macro use is that the minimum focus distance is just 163mm from the focal plane.

Take away the distance between the lens mount and sensor (46.5mm) and the length of the lens (64.5mm), and at the minimum focus distance, the subject will be just 52mm from the front element. Shooting at f/22 means that the nearest point of the depth of field is 47mm from the front
of the lens. As such, this then limits the ways that the macro subject can be lit. Photographing it from above requires additional lighting in the form of small LED lights or a ringflash, as the working 1:1 distance causes the subject to almost always be in shadow. Although photographing insects in daylight is possible, the working distance means that it is difficult to get close without scaring
the insects away.

For stationary subjects it is easier to be more creative with how the subject is lit, but larger studio lights and even flashguns will most likely be out of the question.

Image: At 1:1 reproduction you have to get extremely close to your subjects 

Image quality

The first things that impressed me about the Nikkor 40mm f/2.8 lens were the rich colours and good level of contrast that it produces. These can really help to accentuate small details. What made this level of contrast even more evident was when I took the same image with a 55mm f/3.5 Micro Nikkor optic, dating from the mid-1960s.

This lens has a lower level of contrast, and when images are taken against a bright-white background they look very dull and desaturated. With anti-flare coatings, the bright white background was no problem for the 40mm f/2.8 lens and the images have a good level of contrast.

What is interesting is that this level of contrast is consistent throughout the aperture range of the lens on test. There is a slight drop in sharpness at f/2.8, but between f/4 and f/11 all images have about the same level of detail. At f/16 and f/22 there is a noticeable drop in sharpness and resolution, according to our test-chart results. In real-life examples, although the slight loss of sharpness is noticeable by comparison, in isolation images are still perfectly acceptable.

Image: The 40mm f/2.8 lens has only slight distortion and produces images with a good level of contrast

Generally, the 40mm f/2.8 lens performance is much like that of the AF-S Nikkor 50mm f/1.8G lens that we tested in AP 23 July. Similar optical coatings have been used on both lenses, and although two more optical elements are used in the 40mm f/2.8 lens, image sharpness in both lenses is almost identical.

There is some optical distortion produced by the lens, namely a slight pincushion effect. This is obviously much more noticeable at the closest focus distance, and those wishing to use the lens for photographing printed material, such as stamps, should consider this before shooting. Leave a little space around the subject to allow for software correction and subsequent cropping.

Red/cyan chromatic aberration is visible in some situations. The in-camera processing should remove, or at least reduce, any chromatic aberrations in JPEG images, but those editing raw files will have to perform the task manually. I found that it was very easy to remove the chromatic aberration using Adobe Camera Raw, with only a slight shift needed.

Vignetting is also present when shooting, although in most situations it will only ever be really noticeable when shooting at f/2.8. Once again, it can be corrected by switching on the in-camera vignetting control, or it can be easily removed from raw files using editing software.

Why a 40mm focal length?

A focal length of 40mm is a strange length for a macro lens. As we have already discussed, at the closest 1:1 focus distance the subject is around 5cm away from the front of the lens. This can cause problems when lighting the subject, and also make taking pictures of bugs and insects more challenging than it need be.

Most macro photographers shoot using 105mm, 150mm and even 200mm lenses. These focal lengths allow the photographer to be much further away from the subject, making it easier to place lights between the camera and subject. At this distance it is also less likely that insects will be scared away. So why would a 40mm macro lens be a good idea?

First, having a wider angle of view gives images a more natural perspective, making us feel closer to the subject.. While the narrower view of a longer focal length may allow the photographer to stand further away, less of the subject’s surroundings will be captured in the image, making us feel more distant.

The lens offers the equivalent field of view of a 60mm lens on a 35mm, full-frame camera. In the past, Nikon has produced 55mm macro lenses and currently has a 60mm macro lens in its line up. The 40mm optic therefore provides a DX equivalent to these lenses.

Another factor is that not everyone who enjoys macro photography takes pictures of insects that will be scared away if they get too close. Although lighting may still be a little awkward, for those who photograph documents, stamps and textures, the close-focus distance is less of a concern. The
relatively simple design of the lens also allows distortions to be kept to a minimum – something that is crucial for those photographing flat subjects for archival purposes.

The autofocus range lock on the side of the lens also hints at why Nikon has introduced the optic. By not using the macro range of the lens, it becomes a ‘standard’ model. For those Nikon users with DX-format cameras who are considering buying a 50mm focal-length optic, but who also would like the ability to photograph macro subjects, the Nikkor 40mm f/2.8 lens could fulfil both these requirements, albeit with compromises, such as the close-focus distance and the slightly larger f/2.8, rather than f/1.8, aperture of a standard 50mm lens.

Another reason why Nikon has introduced this lens is its affordability. At around £250, the Nikkor 40mm f/2.8 is aimed squarely at those who may otherwise feel that a Micro Nikkor macro lens is out of their price range. Virtually doubling up as both a macro and standard lens, the AF-S DX Micro Nikkor 40mm f/2.8G looks to be a good-quality, affordable macro optic for enthusiast photographers.

Resolution

We tested the AF-S DX Micro Nikkor 40mm f/2.8G lens on a Nikon D7000 DSLR camera. An image was taken of our test chart with the lens set to each of its apertures, with the results shown below. Overall the lens performs very well, with it being at its sharpest at f/8. However, there is a reasonably significant fall off in sharpness at f/22.

Image: At its centre the 40mm macro lens is very sharp, revealing the finest of details

Our verdict

Although the AF-S DX Micro Nikkor 40mm f/2.8G has obvious limitations when it comes to macro photography, the pros it offers to entry-level and enthusiast photographers outweigh the cons. The lens is sharp, resolving a great deal of detail, while the multicoated optics produce a good level of contrast and colour.

There are distortions, but these are minimal and easily removed in editing software, or in-camera if you are shooting JPEGs.

The obvious disadvantage is the close working distance to the subject, but the lens does offer more than just macro abilities. I found the 60mm equivalent focal length a good replacement for a standard lens, particularly for documentary shooting and mid-length portraits.

In this regard, the AF-S DX Micro Nikkor 40mm f/2.8G is a really great option for entry-level photographers looking to buy a fixed-focal-length optic to complement their kit zoom.

Similarly, enthusiasts who only dabble with macro imagery can do so without breaking the bank. However, if you specialise in macro, it’s worth paying more for the convenience of a longer focal length.