Nikkor 24mm f/2.8 AI-S : Review


Introduction

This is one of my favourite lenses ever, the Nikkor 24mm f/2.8 AI-S, and here will be tested with the Nikon D700 full-frame DSLR. It’s one of those lenses that may last forever and it’s a joy to shoot with. It has CRC (close-range correction) for great performance shooting at close distances. It’s very compact for a wide lens, I can put it in my jacket’s pocket and use it in a pinch everytime I need to shoot wide.
So let’s start with the size comparison with the D700:

The lens is older than me, it was introduced in 1977 and became a very popular lens then. I had been searching for a nice wide prime to use on the D700 and this was a blessing. It is relatively cheap in the used market today, but some stores are still selling them brand new for more than 500€. The AF-D version has the same optical formula and sells for about 430€, but it’s plastic.
This prime lens has 9 elements in 9 groups, with a floating element for CRC. The AF-D version has the same optical construction, but it’s may not be easy to find a good copy – opinions from other users with this AF-D version are everywhere from stellar to unusable. This lens is a masterpiece of construction like the other Nikkors back in the old days, when everything was metal with engraved markings for aperture and focus distance.
Used lens prices are everywhere in the range of 180€ to 400€, and that shows how well this lens keeps its value over the years. This is an eternal lens, as long as it’s free from fungus and doesn’t fall of a cliff, of course.


Technical Specifications

Focal length 24mm
Maximum aperture f/2.8
Minimum aperture f/22
Field of view 84 degrees (on FX)
Weight 250g
Dimensions 46 x 60mm (48 x 60mm at minimum focus distance)
Optical construction 9 elements in 9 groups
Aperture blades 7, straight
Filter diameter 52mm
Minimum focus distance 29cm (20cm from the front element)
Hood HN-1, optional
Mount AI-S, no CPU


Mechanical Characteristics

Zoom ring n/a
Focus ring Metal with rubber finish, with infinity stop
Focus throw 85 degrees
Focus motor No
Optical stabilizer No
Front element rotation while zooming n/a
Front element rotation while focusing No
Internal focusing No
Lens extension while focusing Yes, 2mm
Lens extension while zooming n/a
Maximum magnification 1:8.8


Handling

The lens is dwarfed by the D700, but with a weight of 250g the lens is much heavier than it looks, but that’s the result of using metal everywhere in its construction. Handling the lens is a breeze – the focus ring is very large and buttery smooth (it still is, for a lens with this age), and it’s a joy to use. I don’t mind using manual focus with wide lenses since focusing is so easy with them, and with the help of the D700’s viewfinder it’s even easier. The focus ring is finished with a very rough rubber that feels so great on my fingers, and with a throw of 85 degrees there’s a lot of room for precise focus. A great thing this lens has, is that there’s a hard stop at infinity; when I shoot astrophotography I just turn the focus ring around to this hard stop and that’s it, perfect focus on the stars!
The front element doesn’t rotate while focusing, so using polarizers is no problem.
As a non-CPU lens, one has to configure the lens on the D700 as “non-CPU” so it could read whatever aperture value is choosen. The aperture is selected using the aperture ring on the lens instead of in-camera, and it doesn’t allow to select half-stops or thirds-stops. These are not issues in practice, but the aperture value must be checked from time to time since the aperture ring is not lockable.


Resolution

For the resolution test I shot the 5 Euro bill as usual. Focus was achieved using Live View to avoid auto-focus imprecisions and to compensate for possible field curvature issues.
The first column shows a crop of the image center, the corner crop is on the second column (the expected DX border) and the third column shows a crop of the extreme FX corner. Each row represents an aperture setting, from maximum to f/22 in full stops. Here are the results:

The center resolution is already on its maximum value, which I honestly wasn’t expecting from such old design, and only drops a little bit at f/16 due to diffraction and more so at f/22. As expected, the corner resolution is much softer overall at f/2.8, but DX shooters would probably be happy here (look at the second column); FX users will get much worse corners, though. By f/4 the center resolution seems to improve a bit, but what’s happened here is that at f/4 there’s more light transmission to the sensor, which does make seem that images are a little sharper, but they’re only clearer. Here, the corners improved a lot, which will please DX users, and the FX corners were greatly improved as well.
From f/5.6 to f/11 the lens deliverz stunning sharp images both at the center and corners. The sweet spot for FX is from f/8 to f/11, the values I typically choose for landscape shots.
Overall, this is very high performance for such old wide angle lens, the results are very pleasing and this makes me understand why the lens was so popular back in the days. And today it still rocks.


Distortion

Here is the brick wall shot:

The lens has a high level of barrel distortion, and FX users will also have to deal with mustache, giving a wavy shape to horizontal lines, and not only on the top and bottom of the frame, as you can see in sample 5 at the bottom of the page. The barrel distortion is also quite visible in real world shots on vertical lines – just watch the vertical columns on sample 3.
In conclusion, the lens should be used with caution in architecture photography, especially regarding horizontal lines. For landscapes I usually don’t worry about it, but I always pay attention to the horizon line in seascapes.


Vignetting

In this test, I shot a white wall at home using tungsten white balance and set exposure manually:

Vignetting is very strong at f/2.8, that’s why the resolution test was a bit darker at this setting even in the center. At f/4 there’s still considerable vignetting, but it isn’t noticeable stopping down once more. With this lens I’d only worry about vignetting at f/2.8, but personally I rarely use that setting – only for closeups, and vignetting usually gives a nice touch.


Chromatic aberrations

For this test I shot a car from above on a bright sunny day early in the afternoon:

I am amazed at how great this lens is controlling CAs. Even at f/2.8 I could not see any traces of fringing whatever tests I did. It’s perfect.


Coma

Coma was tested using a LED source, at home in a dark room.
I put the light source at the center (first column), corner and extreme corner of the frame (second and third columns, respectively), at maximum aperture and stopped down.

In this matter, the lens disappoints. That’s typical for old designs, and still is for the majority of wide angle lenses, and unfortunately this distortion is very noticeable in astrophotography. Forget it if you were considering this lens for that application and you’re a pixel-peeper. I’ve been using it for that purpose and I try to abstract myself from viewing the borders at 100%.


Flare

I shot a building in construction with the sun sneaking from a window, to see if I could see any flare traces. I started to shoot directly against the sun, then placed the sun at the corner and finally made some shots with the sun just outside the frame.

Shot directly against the sun.
Shot with the sun placed at one corner of the frame.
Shot with the sun just outside the frame.

The lens has a good resistance to flare and ghosting which keeps contrast intact. The problem is that if the sun is in the frame or in the proximity, the internal reflections of light will be easily visible in the pictures, as tiny as those reflections may be. It can be annoying; there were times I thought that the sun was already at a safe distance from the frame, and the lens still catched a small group of reflections. That can be easily solved in post-processing if those reflections are over a homogen background, but may be distracting and impossible to eliminate in textures. Just take a look at the last test image – these are the reflections I’m talking about (look at the second window hole at the left).
In conclusion, it is necessary to frame at a safe distance from the sun, and I advise to get the optional HN-1 or use another device to block reflections definitely.


Bokeh

This is a wide focal lens with 7 straight blades, thus bokeh has to be the last thing you think about when buying this lens.
I took a defocused picture at the widest aperture of the city lights and got crops of the center, corner and extreme corners. The test was repeated for the subsequent two stops.

The lens produces a fairly acceptable bokeh after all at f/2.8, although it has onion artifacts and accentuated edges. In real world shots they’re not very distracting, though. Stopping down soon reveals polygonal shapes as a result of a small number of aperture blades of straight type. That’s in line with every ordinary wide angle lenses. For good bokeh there are better choices such as the 24mm f/1.4 options (Samyang comes to mind).


Macro/Close-up

Although the lens is an old design, it has CRC which allows it to focus as close as 20 centimeters from the front element, resulting in a maximum magnification ratio of 1:8.8. It’s not bad, but I’ve seen much better from other wide angle lenses – the Voigländer Color-Skopar 20mm f/3.5 SL II Aspherical, which I also tested, is just one example, but it’s a modern design and a very different one.
I shot an 1 Euro coin and this is what to expect at the minimum focus distance:


Summary

Build quality 10 All-metal and very professional, there’s nothing to complain about
Handling 8 Fantastic manual focus lens with very rough focus ring, the only downside is having to select aperture on the lens in full stops
Resolution 9 Superb resolution for a wide angle lens, only soft in the corners wide-open and a little at f/4
Distortion 5 Complex barrel and mustache distortion, not suitable for architecture
Vignetting 8 Very strong wide-open, but not noticeable afterwards
Chromatic aberrations 10 This lens reaches perfection here, as did the Voigtländer
Coma 5 Poor, very noticeable in the borders in astrophotography
Flare 8 Doesn’t suffer much and contrast is always on top, but easy to catch a few tiny reflections of light if you’re not careful
Bokeh 4 Acceptable wide-open, but that’s about it
Overall 74% A very sharp wide angle prime lens that is very small and very tough, still one of the best ever that money can buy


Samples

Here are some samples of pictures I made with this lens. Settings: native JPEG, picture control set to Landscape mode, no post-processing applied except reducing to 600 pixel width.

24mm, f/2.8, 1/2500s, ISO 200
24mm, f/8.0, 1/250s, ISO 200
24mm, f/4.0, 1/320s, ISO 200
24mm, f/11, 1/200s, ISO 200
24mm, f/8.0, 1/250s, ISO 200
24mm, f/4.0, 1/1000s, ISO 200