It has been 30 years since Nikon first introduced the original Nikkor 20mm f/2.8 Ai-S lens and long 20 years since the autofocus version, the Nikkor 20mm f/2.8D was released to the market. Since then, the 20mm prime sadly did not receive much attention, so it was about time for Nikon to refresh the line with a modern version. Nikon finally revealed a replacement on September 12, 2014 and the new lens came with a nice surprise – the Nikkor 20mm f/1.8G ED is not only completely revamped in terms of optical design, but it is also 1.3 stops faster than its predecessors. Personally, I have been very interested in checking out the new 20mm f/1.8G lens, because I found the 28mm f/1.8G to be a bit too long for my taste. And although I love my 24mm f/1.4G (see my detailed review here), it is pretty expensive and often quite heavy to carry around. Thus, a wider, lighter and much less expensive lens sounded very appealing to me. I have had the joy of shooting with the Nikkor 20mm f/1.8G for the past three months and as you will see in this review, the lens deserves high praises for its superb optical performance. Without giving any more spoilers, let’s jump into the review and see where and how it shines.
When it comes to ultra wide angle lenses (those lenses that typically cover focal lengths shorter than 24mm on full-frame), many photographers often use zoom lenses, like the Nikkor 14-24mm f/2.8G, Nikkor 16-35mm f/4G or DX zoom / third party lenses, because they give more flexibility in situations where one cannot physically move closer or away from the subject – zoom lenses certainly have their conveniences. But those conveniences often come with their own list of problems, whether it is the high price tag, heavy weight and bulk, smaller maximum aperture or inferior optics. Therefore, prime lenses do have their use and advantages when compared to zooms. When assessing wide angle prime lenses, the biggest challenge for most photographers remains determining the best focal length. Finding out how well a particular focal length can serve one’s needs can be challenging, as it depends on many factors, including the type of photography one is primarily engaged in. Architecture, landscape and astro photographers might often enjoy shorter focal lengths, while portrait photographers generally tend to stay in the 35mm+ range. Even for portrait photography though, there are always situations where an ultra wide angle lens can come in handy (such as when photographing large groups, or composing wide to include more of the scene). So even if one does not frequently use such lenses, some situations call for going very wide. Because of this, I practically always make room for an ultra wide angle lens in my bag.
Having previously used and tested the Nikkor 28mm f/1.8G, I found 28mm on full-frame to be a bit too long for my taste, so I kept my 24mm f/1.4G prime as my workhorse for those wide angle moments. Those 4mm of additional focal length might not seem like a lot, but there is a pretty big difference! And the wider you go, the more noticeable each mm of focal length becomes. The same thing applies to the 20mm f/1.8G – it is significantly wider than a 24mm lens, a difference of 10° in terms of angle of view, as illustrated below:
I have received a number of requests from our readers, who asked me if I could compare the 20mm f/1.8G to the 28mm f/1.8G, but in reality, it would never be an apples-to-apples comparison due to huge differences (almost 20°!) in angle of view. As you can see from the above image, the difference between 20mm and 28mm is massive in terms of field of view.
However, if one decides to go with a single wide or ultra-wide angle Nikkor prime with a budget not exceeding $1K to complement such lenses as 35mm f/1.8G, 50mm f/1.8G and 85mm f/1.8G, then the choice is between the 20mm f/1.8G and 28mm f/1.8G lenses. If I were to pick between 20mm and 28mm, I would pick the former. With modern high-resolution sensors, if I wanted to get a bit tighter, I know I have the option to crop. But if I go with a longer focal length, I am limiting myself in those situations where I cannot move back to get a wider shot. Others will prefer 28mm and skip the 35mm, which also works. My personal choice for modern primes under 100mm today would comprise of: 20mm f/1.8G, 35mm f/1.8G, 50mm f/1.8G and 85mm f/1.8G for budget and 24mm f/1.4G, 35mm f/1.4G, 50mm f/1.8G and 85mm f/1.4G for high-end, which would probably cover 99% of my photography needs. If I considered third party options, I would swap the 35mm f/1.4G and 50mm f/1.8G with Sigma Art f/1.4 series lenses.
So if you are still torn between 20, 24 and 28mm prime lens options and you already have a 35mm, my suggestion would be to explore the 20mm f/1.8G. If you only want a single wide angle lens that is not too wide or too narrow to complement your 50mm, then the 28mm f/1.8G might be a better candidate.
Hope this answers the focal length questions and concerns. Let’s now move on to lens specifications.
1) Lens Specifications
- Nikon Silent Wave Motor (SWM) enables fast, accurate and quiet autofocus.
- Extra-low Dispersion (ED) element offers superior sharpness and color correction by effectively minimizing chromatic aberration.
- Two aspherical lens elements virtually eliminate coma and other types of aberration, even when shooting at the widest available aperture.
- M/A focus mode switch enables quick changes between manual and autofocus operation.
- Rear Focus (RF) provides smooth and fast autofocus while eliminating front barrel rotation and lens length changes.
- Nano Crystal Coat effectively reduces ghost and flare.
- Nikon Super Integrated Coating (SIC) enhances light transmission efficiency and offers superior color consistency and reduced flare.
- Mount Type: Nikon F-Bayonet
- Focal Length: 20mm
- Maximum Aperture: f/1.8
- Minimum Aperture: f/16
- Format: FX/35mm
- Maximum Angle of View (DX-format): 70°
- Maximum Angle of View (FX-format): 94°
- Maximum Reproduction Ratio: 0.23x
- Lens Elements: 13
- Lens Groups: 11
- Diaphragm Blades: 7
- Super Integrated Coating: Yes
- Autofocus: Yes
- AF-S (Silent Wave Motor): Yes
- Internal Focusing: Yes
- Minimum Focus Distance: 0.66 ft. (0.2m)
- Focus Mode: Auto, Manual
- G-type: Yes
- Filter Size: 77mm
- Accepts Filter Type: Screw-on
- Dimensions (Approx.): 3.2 in. (82.5 mm) x 3.1 in. (80.5 mm)
- Weight (Approx.): 12.6 oz. (355 g)
2) Lens Construction
Lens construction is quite advanced for a budget ultra wide angle lens. The Nikkor 20mm f/1.8G contains a total of 13 lens elements, two of which are “Extra-low Dispersion” (ED) lens elements that are typically used on high-end Nikkor lenses to boost sharpness and contrast. In addition, two aspherical lens elements are used for correcting spherical aberration issues, as shown below:
3) Lens Handling and Build
The Nikkor 20mm f/1.8G ED has a similar build as the 35mm f/1.8G ED and other recent Nikkor prime lenses, with a hard and textured plastic exterior, a metal mount and a rubber gasket on the lens mount to provide good sealing against dust making its way into the camera. The lens feels solid in hands, definitely no worse than any of the modern professional Nikkor prime. Size-wise, it is not as small as the classic Nikkor 20mm f/2.8D, but for a reason – with 1.3 stops faster aperture, it is a given that the lens would be larger in comparison. Also, larger size is a good thing, as the lens feels comfortable to support it with your left hand while hand-holding the camera. Unlike the 35mm f/1.8G, there is a gold ring around the front barrel of the lens, which indicates “pro” quality and more complex design (Nano-coating, 2 aspherical and 2 ED elements vs standard coating and 1 of each on the 35mm f/1.8G).
The lens takes standard 77mm filters, which is great if you are planning to use polarizing filters and filter holder systems (vignetting performance with filters is provided further down below). Despite being a pro-grade lens though, the filter thread is plastic, which is unfortunate, as it could potentially wear out with repetitive mounting and dismounting of lens filters if you are not careful. On the bright side, nothing moves when the lens focuses, so you do not have to worry about having to re-adjust your polarizing filter when using it in the field. In contrast, older AF-D lens designs often had rotating front elements, making them hard to use with filters (the 20mm f/2.8D is an exception, due to having inner focus design). Additionally, the front element of the Nikkor 20mm f/1.8G ED does not move in and out like it does on some Nikkor primes and it is not recessed deep inside, making it pretty easy to clean and maintain.
The focus ring is quite thick, making the lens very easy and convenient to use for manual focusing with a thumb and index fingers, whether shooting images or video. A petal-shaped HB-72 Lens Hood is provided with the lens. It snaps easily on the front of the lens and sits tight without wobbling. 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 immediately recognize the focus position and some even provide notifications on the information (“I” button) screen.
As I have already pointed out, the lens is very light and compact – at 355 grams, it is a bit heavier than its predecessor, the Nikkor 20mm f/2.8D, which weighs 270 grams. It is also slightly heavier than the Nikkor 28mm f/1.8G, which weighs 300 grams.
4) Autofocus Performance and Accuracy
The Nikkor 20mm f/1.8G features silent wave motor (SWM) technology, which not only makes autofocus near silent, but also quite fast in operation. Since the lens is so wide, its distance scale is pretty limited – from 0.66 feet (minimum focus) to 1.3 feet, after which it is infinity. As a result, autofocus speed is near-instant: going from near focus to infinity only takes about half a second, which is incredibly fast. Autofocus accuracy is also impressive. Whether I used the lens in bright light, or in low-light indoors conditions at a wedding venue, the lens was able to acquire focus consistently when using the Nikon D750 DSLR. Low-light performance with older Nikon cameras might not be equally as good though, since previous generation bodies are not rated the same (see my detailed Nikon D750 review for more information on this). My copy of the lens coupled very well with both D750 and D810 camera bodies and did not require any AF fine tuning to yield superb sharpness, even wide open.
Let’s take a look at the optical features of the lens and its sharpness characteristics on the high-resolution D810.
5) Lens Sharpness, Contrast and Color Rendition
When I initially saw the manufacturer-provided MTF curve of the Nikkor 20mm f/1.8G ED lens, I got very excited to see how good it looked when compared to the 28mm f/1.8G lens. Both sharpness and contrast of the lens looked very promising at maximum aperture, so I imagined how good the lens would get when stopped down. When I finally measured the lens in my Imatest lab, my early estimates proved to be correct – the lens does indeed perform extremely well for a wide angle lens. Not only did it outperform the 28mm f/1.8G lens, but it also yielded better sharpness figures in the center than the legendary 24mm f/1.4G lens! Take a look at the below chart:
The Nikkor 20mm f/1.8G ED starts out very strong at large apertures. Center performance is excellent wide open, with performance characteristics being very similar to those of the Nikkor 35mm f/1.8G ED lens. At f/2.8, the lens yields very impressive sharpness in the center, which only slightly improves when stopped down. Peak center performance is reached at f/4, with excellent overall performance at f/5.6, where both mid-frames and corners look very good. Unlike the 28mm f/1.8G lens, the 20mm f/1.8G practically had no focus shift and field curvature was far better controlled too. To see how good the above lens compares to other Nikkor primes like 24mm f/1.4G and 28mm f/1.8G, please see the comparisons section further down below.
Thanks to the excellent optical design of the lens, microcontrast is also superb, very similar to what you see on very expensive and high-end Nikkor lenses. Thanks to Nano-coating, Super Integrated Coating and high quality glass used in the lens, the Nikkor 20mm f/1.8G ED yields very natural and pleasing colors.
Wide angle lenses are not suited for yielding pleasing bokeh and the Nikkor 20mm f/1.8G ED is not an exception. As I have previously demonstrated in a number of reviews, use of aspherical elements usually results in onion-shaped bokeh, so if you look really close at how the lens renders bright out of focus highlights, you will definitely see those onion rings. At the same time, out of focus transitions look rather pleasing and not as distracting as they typically do on zoom and lower-end prime lenses, even when stopped down, as shown in the below image samples:
It is important to understand that with such a wide angle lens that reaches infinity at just a little over a meter, one would have to stand very close to a subject to be able to effectively isolate them from the background. And as you might already know, getting too close to your subject will distort their features, so it is best to avoid photographing people at very close distances with this lens. Although I have provided a number of examples of people photography with the Nikkor 20mm f/1.8G, the ones that show subjects close-up are cropped and others clearly show distorted facial and body features. Unless your purpose is to specifically distort the subject, make sure to keep a safe distance and avoid placing the subject in the corner of the frame.
Ultra wide angle lenses like the 20mm f/1.8G are particularly attractive to architecture and landscape photographers, who genuinely care about how such lenses handle vignetting, especially when coupled with filters. To give a good understanding of vignetting performance, I measured the lens with and without filters, at both close distance and infinity (since vignetting performance can vary greatly at different distances). To simulate a standard polarizing filter, I stacked two regular filters together, which ended up being very close to what my Singh-Ray Warming Polarizer is in terms of size. I did this because I wanted the lens to show falloff in a uniform manner for proper measurement and it was hard to achieve it with a polarizer. Here are the Imatest results:
Now this is pretty interesting data to look at. At close / minimum focus distance, vignetting levels are quite normal for a fast prime. However, at infinity, the corners of the lens can get pretty dark, surpassing 3 EV on average, which is rather high. At the same time, there are great news – mounting a standard profile polarizer will not make vignetting worse – note that the second set of the bars in the graph looks pretty darn close to the first. So you can safely use a standard profile polarizer on this lens and you don’t have to worry about introducing additional vignetting. The only time when the lens will vignette noticeably, is if you use a standard polarizing filter and stack more filters on top of it. Here is what the image will look like with a polarizer and a LEE Filter Holder (also standard size) mounted on top of the polarizer:
So keep this in mind when shooting in the field. If you really need to use a CPL together with a filter holder, my recommendation would be to get slim versions of both. Preferably, use a more versatile filter holder that allows mounting a larger polarizer, which will not add additional vignetting to your shots.
Here is the worst case scenario of vignetting performance at f/1.8 (at infinity mark, without filters), as illustrated by Imatest:
8) Ghosting and Flare
Like other pro-level lenses, the Nikkor 20mm f/1.8G comes with high-end Nano coating (Nikon calls it Nano Crystal Coat), which means that the lens is built to handle ghosting and flare very well. Indeed, shooting against bright sources of light has very little effect on the overall image, as demonstrated below:
At the same time, if you put a bright source of light in a wrong spot, you might end up with some surprises:
The above example is perfectly normal – even the most expensive Nikkor lenses will show ghosting and flare in such situations. So be careful when framing your shot and watch out for those undesirable effects.
Please note that using UV and other filters can potentially introduce more flares and ghosting to your images.
When it comes to distortion, the Nikkor 20mm f/1.8G ED measured about the same amount of barrel distortion as both 24mm f/1.4G ED and 28mm f/1.8G ED lenses:
And if distortion bothers you, it is really easy to fix in post-processing. The latest version of Lightroom already has a built-in lens profile for the Nikkor 20mm f/1.8G ED, so you can take care of it with a single click of your mouse.
10) Chromatic Aberration
Lateral chromatic aberration levels are pretty light, particularly at wider apertures when compared to both 24mm f/1.4G and 28mm f/1.8G lenses:
I would not worry about lateral chromatic aberrations though, since those can be easily fixed in Lightroom and Photoshop. As expected on fast aperture Nikkor prime lenses, there is a visible amount of longitudinal chromatic aberration present.
Although the Nikkor 20mm f/1.8G is a great performer for astrophotography compared to other wide angle lenses, don’t be surprised to see stars render into odd shapes at the extreme corners of the frame when shooting at f/1.8, as shown below:
The good news is, stopping down the lens will improve the situation dramatically. As shown above, by f/2.8, points of light are rendered similarly as in the center, so stopping the lens down will certainly improve the situation.
12) Infrared Performance
The Nikkor 20mm f/1.8G is a solid performer for infrared-converted cameras at large apertures. When stopped down to f/5.6 and smaller though, there is a visible hot spot in the center of the frame, as illustrated below (move the slider to see both):
Please keep in mind that the above images have been exaggerated to reveal the hot spot (I dialed -85 in Blacks in Lightroom). The effect is not extreme, but will be visible if you make contrast and black level adjustments.
13) Nikon 20mm f/1.8G ED vs Nikon 24mm f/1.4G ED
Let’s see how the 20mm f/1.8G ED performs when compared to the high-end 24mm f/1.4G ED:
Although the Nikkor 24mm f/1.4G starts out pretty weak at large apertures and might not yield top notch center performance, its overall performance is more balanced in comparison to the 20mm f/1.8G, especially when stopped down a bit. At the same time, when stopped down to f/5.6, both lenses perform very similarly, which shows just how good the 20mm f/1.8G is when compared to the much more expensive and heavier 24mm f/1.4G.
14) Nikon 20mm f/1.8G ED vs Nikon 28mm f/1.8G
Now let’s take a look at how the 20mm f/1.8G ED compares to the longer 28mm f/1.8G:
Again, it is pretty clear that the new 20mm f/1.8G ED outperforms the 28mm f/1.8G ED in center sharpness – its performance is better at all apertures, especially when stopped down to f/4. The same goes for mid-frame at large apertures, where the 20mm f/1.8G shows superior performance. However, the corners is where the 28mm f/1.8G is clearly better, giving superior performance at all apertures. One word of caution though – as I noted in my Nikon 28mm f/1.8G ED review, the 28mm lens suffers from both focus shift and field curvature issues, which can be somewhat painful to deal with. As you can see from the above chart, the 28mm f/1.8G lens shows better corner performance than mid-frame, which is an indication of wavy field curvature.
15) Nikon 20mm f/1.8G ED vs Zeiss 21mm f/2.8
The manual focus Zeiss 21mm f/2.8 has a similar focal length, but it is 1.3 stops slower. At the same time, the build quality of the Zeiss is top notch – a world better than on the Nikkor 20mm f/1.8G. Let’s see how the two compare optically:
WARNING: The copy of the Zeiss 21mm f/2.8 I had was pretty decentered, so the above figures for both mid-frame and corners might not reflect the full potential of the lens. I am planning to test another copy of the Zeiss and will update the below chart as soon as I can.
The Nikkor 20mm f/1.8G is a much sharper lens than the Zeiss 21mm f/2.8, particularly wide open. As you can see from the above chart, the Zeiss cannot match the performance of the Nikkor throughout the frame. Stopped down the performance differences diminish a little, but the Zeiss shows pretty noticeable field curvature and its overall performance is inconsistent. Again, this is based on a flawed sample of the lens – more testing on other samples will be required.
Overall, the 20mm f/1.8G ED shows excellent performance and Nikon definitely deserves high praises for developing such a great lens optically.
Lens after lens, Nikon has been replacing its classics with new generation lenses that are designed for yielding superb sharpness on the latest high-resolution sensors. The Nikkor 20mm f/1.8G ED might not have the heft or build quality of some of the Nikkor classics, but its overall performance, especially relative to its price tag, shows the direction that Nikon has been taking during the past few years in terms of delivering excellent value. As of now, Nikon has a solid stable of lenses for enthusiasts in its f/1.8 line: 20mm f/1.8G, 28mm f/1.8G, 35mm f/1.8G, 50mm f/1.8G and 85mm f/1.8G, all highly praised performers, even when compared to their more expensive f/1.4 counterparts. In my view, when you factor in performance vs price, these lenses are making the f/1.4 line seem like “specialty” offerings that are tailored for specific needs, rather than being the high-end tools desired by every Nikon camera owner.
For its $800 MSRP price tag, the Nikkor 20mm f/1.8G ED as such represents tremendous value. As I have demonstrated in this review, the lens has very quick and accurate autofocus and excellent center sharpness when compared to 24mm and 28mm lenses, especially at maximum aperture. It handles chromatic aberrations, distortion, ghosting and flare very well and does not suffer from focus shift and wavy field curvature problems that other lenses are known to exhibit. Although extreme corners do show signs of problematic handling of coma at f/1.8, stopping down to f/2.8 or cropping the frame a bit make this lens a great choice for astrophotography needs (in fact, I am planning to use this lens for my astrophotography needs and I will update the review with more sample images as soon as I can). The lens also seems to be a good candidate for infrared photography, though one has to be careful when using small apertures – the lens does show hot spots starting from f/5.6. Its biggest drawbacks are weaker corner performance, excessive vignetting when shooting at infinity focus at wide apertures and a cheaper, more plasticky feel when compared to high-end Nikkor lenses.
Overall, I highly recommend the Nikor 20mm f/1.8G ED lens for both enthusiasts and professionals. It is a solid performer that nicely fills the 20mm “ultra wide angle prime” gap for many photographers.
17) Where to buy and availability
B&H is currently selling the Nikkor 20mm f/1.8G ED lens for $796.95 (as of 12/28/2014).
18) More Image Samples
All Images Copyright © Nasim Mansurov, All Rights Reserved. Copying or reproduction is not permitted without written permission from the author.
Nikkor 20mm f/1.8G ED
- Optical Performance
- Bokeh Quality
- Build Quality
- Focus Speed and Accuracy
- Size and Weight
Photography Life Overall Rating