Nikon 40mm f/2.8G DX Review

The Nikon 40mm f/2.8G DX, also known as “AF-S DX Micro-NIKKOR 40mm f/2.8G” is a consumer-grade lens for photo enthusiasts that need an affordable macro lens with good performance characteristics. In the current line of macro lens offerings from Nikon, this lens comes at the lowest price point and shortest focal length. With the former being good news, the latter can be a problem in some situations, specifically when approaching subjects very closely (read more on this issue below). With the current great fast aperture prime lens line from Nikon such as Nikon 35mm f/1.8G and Nikon 50mm f/1.8G, one might wonder what the Nikon 40mm f/2.8G DX has to offer that the other primes cannot accomplish. How does it differ from other affordable primes? In this review, I will talk about the capabilities of the Nikon 40mm f/2.8G DX and provide a detailed report on its strengths and weaknesses, along with a summary of thoughts about the lens based on my two month experience with it.

While the lens is limited to cameras like Nikon D3100, D5100 and D7000 with a DX sensor and comes at a very attractive price point of $279, it has Silent Wave Motor / AF-S, which allows the lens to silently autofocus on all modern Nikon DSLRs, and Super Integrated Coating, which dramatically reduces lens flare and ghosting. It is a small and relatively lightweight lens that weighs only 10 ounces (280 grams), which is roughly 4 ounces heavier than the super lightweight Nikon 50mm f/1.8G. Other notable features include 1.0x reproduction ratio (more on that later), 0.53 ft minimum focus distance (from the sensor, not the lens barrel), 7 semi-rounded diaphragm blades for pleasant-looking bokeh, a focus limiter switch to increase autofocus speed, 3 focus modes with autofocus override and a 52mm filter size. In short, a great list of features at a low price.

One question I get asked a lot on DX lenses, is whether DX lenses have to be multiplied by the crop factor of 1.5x to gets their true field of view or not. As I have explained in my “Equivalent Focal Length and Field of View” article, it does not matter if you use a DX or a full-frame lens – the focal length of a lens never changes when used on different size sensors – only the angle of view does. In other words, you see wider with full-frame sensors and narrower with crop-factor sensors. This means that the Nikon 40mm f/2.8G DX has a field of view equivalent to approximately 60mm in full-frame format. So think of it as a cheaper and lighter alternative to the Nikon 60mm f/2.8G ED (when the 60mm is mounted on a full-frame camera).

In this review, I will provide a thorough analysis of the Nikon 40mm f/2.8G lens, along with image samples and comparisons against the Nikon 35mm f/1.8G DX and Nikon 50mm f/1.4G lenses.

1) Lens Specifications

Main Features:

1. Nikon Silent Wave Motor (SWM) enables fast, accurate and quiet autofocus.
2. M/A focus mode switch enables quick changes between manual and autofocus operation.
3. Nikon Super Integrated Coating (SIC) enhances light transmission efficiency and offers superior color consistency and reduced flare.
4. The Close-Range Correction system makes each lens group move independently to achieve superior performance at close distances.

Technical Specifications:

1. Mount Type: Nikon F-Bayonet
2. Focal Length: 40mm
3. Maximum Aperture: f/2.8
4. Minimum Aperture: f/22
5. Format: DX
6. Maximum Angle of View (DX-format): 38°50′
7. Maximum Reproduction Ratio: 1.0x
8. Lens Elements: 9
9. Lens Groups: 7
10. Compatible Format(s): DX
11. Diaphragm Blades: 7
12. Distance Information: Yes
13. Super Integrated Coating: Yes
14. Autofocus: Yes
15. AF-S (Silent Wave Motor): Yes
16. Minimum Focus Distance: 0.53ft (0.163m)
17. Focus Mode: Auto, Manual, Auto/Manual
18. G-type: Yes
19. Filter Size: 52mm
20. Accepts Filter Type: Screw-on
21. Dimensions: (Approx.) 2.7×2.5 in. (Diameter x Length), 68.5×64.5mm (Diameter x Length)
22. Weight: (Approx.) 9.9 oz. (280g)
23. Supplied Accessories: LC-52 52mm Snap-on Front Lens Cap, LF-4 Rear Lens Cap, HB-61 Bayonet Hood, CL-0915 Flexible Lens Pouch

2) Lens Use and Autofocus Speed / Accuracy

So, what would you use a lens like the Nikon 40mm f/2.8G DX for and how does it differ from other excellent Nikon primes like the Nikon 35mm f/1.8G or the Nikon 50mm f/1.8G? In Nikon’s official literature, the lens is listed as “AF-S DX Micro-NIKKOR 40mm f/2.8G”. This might sound confusing, but Nikon’s “micro” term means the same thing as “macro”. As a macro lens, the Nikon 40mm f/2.8G can do something that regular primes normally cannot, which is focus on a subject from a very close distance. You have probably already seen beautiful images of flowers, insects and other small objects captured very closely with plenty of details – those images are typically shot with macro lenses. While most lenses can only focus beyond the “minimum focus distance” due to their construction limitations, macro lenses are specifically engineered to extend optical elements away from the sensor in order to be able to focus closer on subjects. The Nikon 40mm f/2.8G DX is a great example of this extension process – when the lens is focused at infinity, its lens barrel is at its shortest length, while focusing on a close subject extends the lens barrel significantly, as can be seen in this image:

Because of this physical extension of optical elements away from the sensor, some amount of light is lost before it reaches the sensor. To compensate for the light loss, the lens automatically decreases its aperture. Therefore, you will notice that although the maximum lens aperture in lens specifications and literature states f/2.8, the actual lens aperture will vary from f/2.8 to f/4.2, depending on how close you are to the subject. In addition, because most modern macro lenses are designed to be able to focus both on far objects at infinity and very close objects with high precision, lens elements that control focus must move slowly in small increments. In turn, this translates to many rotations of the focus ring that are required to go from closest focus to infinity, making these lenses rather slow when trying to focus between close and far objects. To speed up autofocus, Nikon provided a close focus limiter switch that allows limiting focus from infinity to 0.2 meters (∞-0.2m). When photographing non-macro subjects, the Nikon 40mm f/2.8G autofocuses fairly fast, just like many other Nikkor primes. When focusing on very close subjects, AF speed, reliability and accuracy can drop, especially in low light situations. At times, you might find it easier to use manual focus when doing macro photography.

Despite these shortcomings, macro lenses are designed to be extremely sharp from center to corner of the frame. Good sharpness is pretty much required when photographing objects at close distances for macro photography. Understanding this very well, lens manufacturers surely do make them sharp and the Nikon 40mm f/2.8G DX is no exception here. When subjects are captured at extremely close distances, depth of field and subject isolation are also equally important. This puts even more stress on lens manufacturers to try to engineer macro lenses that can render good looking bokeh. As a result, because of great image clarity, sharpness and colors, some photographers choose to use macro lenses for portraiture. The Nikon 105mm f/2.8G VR, a macro lens, is a very popular lens among portrait and wedding photographers for the same reasons. As for 1:1 reproduction ratio language, it simply means that if you took an object that has the same size as the sensor of the camera and physically put it on the same camera sensor, it would cover up the entire surface of it. For example, a full frame sensor has an imaging area of approximately 24x36mm, so if you photographed an object as small as 24x36mm in size, it would fill up the frame when focused at the closest distance.

Now that you understand the mechanical and optical differences between macro and regular lenses, let’s talk about what Nikon is trying to do with the 40mm f/2.8G DX. Being a low-cost alternative to full-frame macro lenses, Nikon is pushing the 40mm f/2.8G DX to be used for macro and portrait work. In their marketing material it clearly states “ideal for shooting general close-ups, delicate flowers, detailed collectables, copy photography, portraits, landscapes and more”. Ignore the last word “landscapes”, because this lens would not be very practical for most landscape photography, except in cases when you need to focus on a small part of a landscape or when shooting panoramas. So if we filter out “landscapes”, we are left with “close-ups, delicate flowers, detailed collectables, copy photography” – all macro – and “portraits”. Clearly, trying to kill two rabbits with a single bullet. How well it can do both is a different subject. Being primarily a macro lens first and portrait lens second, I wanted to find out how it does with photographing small to large objects at extremely close and close distances. What I discovered, is that the Nikon 40mm f/2.8G is excellent for photographing flowers, food and other medium-size objects, but not so suitable for photographing smaller subjects. As I have mentioned in the beginning of this review, this has to do with the closest focus distance. Because this distance is so small, photographing tiny subjects at extremely short distances could become a problem, simply because the lens is physically too close to the subject and might block some or all of the light that reaches the subject. Unless the light is coming from the side of the subject, it is too difficult to photograph subjects without casting a shadow.

3) Lens Handling and Build

Similar to the recently introduced Nikon prime lenses, the Nikon 40mm f/2.8G has a solid build, with a plastic body and a metal mount. Seems like Nikon is not using the same cheap plastic mounts on prime lenses like on the Nikon 18-55mm, which is great news, especially given the price of the lens. Similar to other Nikkor primes, the Nikon 40mm f/2.8G DX also has a rubber gasket on the lens mount, which provides good sealing against dust making its way into the camera. The rubber gasket definitely helps not only in reducing sensor dust, but also in reducing the amount of dust that could potentially end up inside the lens. As I explained in my “what to do with dust inside lenses” article, it is quite normal for lenses to suck air in and out when focusing or zooming in/out.

Size-wise, it is a little narrower and taller than the Nikon 50mm f/1.8 / f/1.4G lenses. Here is a comparison between the Nikon 40mm f/2.8G and Nikon 50mm f/1.4G:

Similar to other Nikon 35mm and 50mm lenses, the Nikon 40mm f/2.8G is not weather sealed. Nikon lenses without gold rings are not designed to withstand tough weather as professional lenses. That’s why Nikon does not specifically mention weather sealing in their marketing materials on cheaper prime lenses. If you take a good care of the lens, you should have no problems with using it in various weather conditions.

As for the focus ring (which operates very smoothly), it is conveniently located on the front of the barrel, making it easy to manually focus with a thumb and index fingers while shooting images or video. The lens comes with an “HB-61″ bayonet lens hood, which sits tight once it is snapped on the front of the lens. The M/A and M switch on the side of the lens allows autofocus with manual focus override and full manual focus operation. The latest Nikon DSLRs like Nikon D5100 immediately recognize the focus position and provide notifications on the information (“I” button) screen.

4) Lens sharpness, contrast and color rendition

As I reveal in my sharpness tests in the subsequent pages of this review, the performance of the Nikon 40mm f/2.8G DX is excellent throughout the aperture range. You can see many examples of lens sharpness taken in a controlled environment in the next page, along with comparisons against other lenses.

5) Bokeh

Bokeh is a very important characteristic of portrait and macro lenses. While testing the Nikon 40mm f/2.8G lens, I paid close attention to its bokeh characteristics and took a number of shots at maximum and smaller apertures. As you can see from some of sample images in this review and the two sample shots below, the Nikon 40mm f/2.8G DX renders pretty good-looking bokeh in general. Background highlights are very smooth at large and smaller apertures, although some visible outlines could be present around very bright highlights. I would say for a macro lens of this class, there is not much to complain about its bokeh.

6) Vignetting

Most prime lenses heavily vignette when shot wide open and the same is true for the Nikon 40mm f/2.8G, so no surprises here. The good news is that as you stop down to f/4.0, vignetting decreases significantly and by f/5.6 vignetting is completely gone. Take a look at lens vignetting at different apertures:

If vignetting is an issue for you, it is easy to fix in post-processing, so I would not worry about it. When Adobe adds the lens profile for the Nikon 40mm f/2.8G into their Camera RAW, you will be able to remove the effect of vignetting with a single click through the Lens Corrections sub-module in Lightroom.

When mounting the Nikon 40mm f/2.8G on an FX camera, you get a similar result as with the Nikon 35mm f/1.8G (with DX crop turned off) – the far corners get dark and even darker when stopped down. Here is a sample image of the 40mm f/2.8G mounted on the D3s @ f/11:

7) Ghosting and Flare

Surprisingly, ghosting and flare are controlled very well on the Nikon 40mm f/2.8G DX Micro. I took pictures with the sun in the frame and right out of the frame and I saw a very moderate amount of ghosting and flares, like on nano-coated pro lenses. This effect might worsen for macro subjects, because the front element comes way out, exposing the front element to bright sources of light. Here is a sample image with a bright reflection of the sun in the center of the frame:

8) Chromatic Aberration and Distorion

Distortion is also controlled very well, I only saw a small amount of pincushion distortion at close distances. As you move away from the subject, distortion starts to disappear completely. As for chromatic aberration, there is only a very slight amount of it present at large and smaller apertures. However, just like with other Nikkor primes, the amount of longitudinal chromatic aberration (LoCA) is rather high at the maximum aperture of f/2.8, which gradually decreases when the lens is stopped down.

Let’s now move on to the good stuff – Sharpness tests. Select the next page below.

9) Sharpness Test

Some technical junk:

1. White Balance: Auto, changed to “Custom”: 3100 Temp, +10 Tint in Lightroom
2. ISO: 200
3. EXIF information is preserved in the images
4. Lens was mounted on Nikon D7000 Camera and Gitzo tripod
5. Focusing was performed through Live-View Contrast Detect
6. Mirror Lock-Up mode with Exposure Delay set to “On” and remote cable release to completely eliminate camera shake
7. Long exposure NR: Off
8. Image Format: RAW
9. Lightroom settings: Default settings
10. Lightroom export: sRGB JPEG Quality 80
11. Testing was performed at f/2.8, f/4.0, f/5.6 and f/8.0 apertures
12. Nothing was moved during testing

10) Sharpness Test – Nikon 40mm f/2.8G Center Frame

The Nikon 40mm f/2.8G DX Micro has very good center sharpness, as can be seen below. Wide open at f/2.8, the image is a tad softer and slightly darker due to vignetting. Vignetting disappears in the center by f/4.0 and the image gets slightly sharper:

Stopped down to f/5.6 brings even more sharpness and f/8.0 seems to be the sweet spot for this lens:

I am not including smaller apertures, because stopping down the lens beyond f/8 does not improve sharpness and only reduces image quality due to diffraction.

11) Sharpness Test – Nikon 40mm f/2.8G Corner Frame

The corner performance of the Nikkor 40mm f/2.8G Micro at large apertures is surprisingly good. The lens is already very good at f/2.8 and looks even better at f/4.0:

If it was not for vignetting in the extreme corners, the first image would have looked very close to the second one. Let’s see what happens when we stop down to f/5.6 and f/8.0:

By f/5.6 the lens reaches its maximum sharpness and stopping down the lens further does not improve sharpness. Looks like the sweet spot for the corners is at f/5.6.

Overall, the sharpness results are very impressive for this lens, but the above crops are meaningless without a comparison against other lenses. Let’s move on to comparisons against other comparable lenses.

Compared to Nikon 35mm f/1.8G

The Nikon 35mm f/1.8G is also a low-cost DX lens that is suitable for everyday photography. It is both faster (f/1.8 maximum aperture vs f/2.8) and cheaper than the Nikon 40mm f/2.8G. In this comparison, I wanted to see how the two compare against each other in sharpness tests, both in the center and in the extreme corners.

12) Nikon 40mm f/2.8G vs Nikon 35mm f/1.8G Center Frame

I always like to check how lenses with different maximum aperture compare wide open. Let’s see how the 35mm fares against the 40mm at its maximum aperture of f/1.8 (Left: Nikon 40mm f/2.8G @ f/2.8, Right: Nikon 35mm f/1.8G @ f/1.8):

Both lenses perform well, but the Nikon 40mm f/2.8G is sharper wide open. Let’s now see with both at the same aperture of f/2.8 (Left: Nikon 40mm f/2.8G @ f/2.8, Right: Nikon 35mm f/1.8G @ f/2.8):

As can be seen from the above crops, the Nikon 35mm f/1.8G catches up with the Nikon 40mm f/2.8G at f/2.8.

13) Nikon 40mm f/2.8G vs Nikon 35mm f/1.8G Corner Frame

Since the wide open corner performance of the Nikon 35mm f/1.8G is weak, I decided to only show both lenses at the same aperture of f/2.8 (Left: Nikon 40mm f/2.8G @ f/2.8, Right: Nikon 35mm f/1.8G @ f/2.8):

Even stopped down, the corner performance of the Nikon 35mm f/1.8G is no match to the Nikon 40mm f/2.8G. In addition to sharpness problems, the Nikon 35mm f/1.8G clearly shows a heavy amount of lateral chromatic aberrations, while the Nikon 40mm f/2.8G is much cleaner with barely visible CA in the corners.

14) Nikon 40mm f/2.8G vs Nikon 35mm f/1.8G Conclusion

As can be clearly seen from the above image crops, the Nikon 40mm f/2.8G can yield much sharper images than the Nikon 35mm f/1.8G at large apertures. The good news for the 35mm f/1.8G is that it quickly catches up with the Nikon 40mm f/2.8G in the center when stopped down to the same aperture, but needs to be stopped down to f/5.6 and smaller in the corners to show comparable results. This shows that both lenses were optimized for different purposes. While the Nikon 40mm f/2.8G is a macro/portrait lens, the Nikon 35mm f/1.8G is a normal lens for everyday needs, so we are comparing a specialized lens with a general-purpose lens. Except for vignetting, the Nikon 35mm f/1.8G is weaker than the Nikon 40mm f/2.8G DX Micro in many optical comparisons, including distortion, chromatic aberration and bokeh. Its obvious advantages are larger maximum aperture of f/1.8 and cheaper price; but the question I have already gotten from many of our readers is – which one is a better buy? It is not easy to answer this question, because we are not comparing apples to apples here. The 5mm focal length difference is huge and it felt like 40mm was a little too long for everyday photography when I was testing the Nikon 40mm f/2.8G. On the other hand, the Nikon 35mm f/1.8G is very sharp in the center wide open, giving more opportunities to shoot in low-light situations. Therefore, I would say that you have to choose your priorities when thinking which one to buy. If you are into photographing details and macro, occasionally taking pictures of people, the Nikon 40mm f/2.8G DX Micro is an excellent choice. If you just want a general-purpose lens with good low-light capabilities for everyday photography, the Nikon 35mm f/1.8G DX is a better choice in my opinion.

Compared to Nikon 50mm f/1.4G

While testing the AF-S Nikkor 40mm f/2.8G DX I decided to compare it against my Nikon 50mm f/1.4G lens. In order to get a similar field of view, I had to move my setup back and forth to be able to provide a more or less fair comparison between these lenses.

15) Nikon 40mm f/2.8G vs Nikon 50mm f/1.4G Center Frame

Let’s see what happens when both lenses are wide open (Left: Nikon 40mm f/2.8G @ f/2.8, Right: Nikon 50mm f/1.4G @ f/1.4):

On a high resolution DX body, the Nikon 50mm f/1.4G seems to out-resolve the Nikon 40mm f/2.8G wide open. The Nikon 40mm f/2.8G also has visible chromatic aberration in comparison. How about when both lenses are at the same aperture of f/2.8:

Here we can clearly see that the Nikon 50mm f/1.4G is much sharper in the center when it is stopped down by two stops to f/2.8. Now let’s stop down both lenses to f/4 and see if it will make a difference:

The difference is now bigger, but interestingly, the Nikon 40mm f/2.8G is still not even as sharp as the 50mm f/1.4G at f/2.8. Both lenses get very close only at around f/8.

16) Nikon 40mm f/2.8G vs Nikon 50mm f/1.4G Corner Frame

Let’s see if we can see the same consistent result in the corners. Here are both lenses wide open (Left: Nikon 40mm f/2.8G @ f/2.8, Right: Nikon 50mm f/1.4G @ f/1.4):

As I have demonstrated before, the Nikon 40mm f/2.8G has very good corner sharpness and the Nikon 50mm f/1.4G is no match wide open. What if we stop it down to f/2.8? Let’s take a look:

The Nikon 50mm f/1.4G gets much better when stopped down to f/2.8, but it still cannot quite reach the resolving power of the Nikkor 40mm f/2.8G DX.

The differences pretty much go away only when the Nikon 50mm f/1.4G is stopped down to f/5.6 and smaller.

17) Nikon 40mm f/2.8G vs Nikon 50mm f/1.4G Conclusion

Being almost twice as expensive and 10mm longer in focal length, the Nikon 50mm f/1.4G performs very well against the Nikon 40mm f/2.8G in the center, yet not so well in the corners. This time we are comparing a macro lens with a portrait lens and once again, it is not an apples to apples comparison. When it comes to other lens characteristics, both have their strengths and weaknesses – the Nikon 50mm f/1.4G has less vignetting (at f/2.8), great center sharpness and less chromatic aberration, while the 40mm f/2.8G DX has better bokeh and less distortion. The biggest strength of the 50mm f/1.4G is its longer focal length and larger maximum aperture, which translate to better low-light capabilities along with shallower depth of field and thus better subject isolation capabilities. Hence, if you are after a good portrait lens, the Nikon 50mm f/1.4G is a better choice (actually the Nikon 50mm f/1.8G would be a better choice in my opinion, since it is even better than the 50mm f/1.4G) than the 40mm f/2.8G. For photographing macro subjects, the 40mm f/2.8G is the obvious choice. For everyday photography on a DX sensor, on the other hand, the Nikon 40mm f/2.8G would be a better candidate than the 50mm, although I believe that its focal length is still a little too long for that purpose, making the Nikon 35mm f/1.8G the most suitable of the three.

18) Summary

During my two month journey with the Nikon 40mm f/2.8G DX Micro, I had a number of opportunities to use the lens for different types of photography. I tried it out for macro and landscapes during my trips to Yellowstone and Colorado mountains, shot an engagement along with Lola and took pictures of my kids and other people. So I can say that I have a pretty good understanding of its capabilities and shortcomings. The focal length was the biggest problem for landscape photography when shooting on a DX camera, simply because I had a hard time fitting scenery into my frame; although, for distant scenery and panoramas (holding the camera vertically), it worked out quite well. I enjoyed shooting portraiture with it and despite being a macro lens, it snapped into focus rather quickly every time I pointed it at my subject. Using the focus limiter switch also helped increasing the AF speed quite a bit. As for macro use, I was pleasantly surprised by the capabilities of this lens for shooting macro subjects. Its sharpness is very good from center to corner and many of the images of flowers and other medium-size objects came out tack sharp with beautiful colors. The biggest weakness of the Nikon 40mm f/2.8G DX, in my opinion, is its short focal length when shooting macro. This sounds strange – too long for landscapes and too short for macro, but that’s kind of how I felt when photographing small subjects like insects. While I could approach them very closely, the lens would often cast a shadow and I had to either pull back or reframe my shot to exclude the shadow. In many cases, I had to block the light completely. I know that there are some workarounds to this, like using a setup with speedlights or ringflashes, but I simply did not have the time or patience to set everything up. I have been using the Nikon 105mm f/2.8G VR for macro work for a while now and I have not experienced this kind of a problem, because I can fill the frame without getting too close. So if you are into photographing small insects, the Nikon 105mm f/2.8G VR or the Nikon 200mm f/4.0D would be better candidates for sure. In short, this lens is best suited for large to medium-size macro photography and some portraiture. Food photographers will love this lens.

19) Where to buy and availability

B&H is currently selling the Nikon 40mm f/2.8G DX Micro lens for $279.95 (as of 10/16/2011).

20) More image samples

All Images Copyright © Nasim Mansurov, All Rights Reserved. Copying or reproduction is not permitted without written permission from the author.