20mm f2.8 AI-S, my first super-wide angle manual lens

[Zang]

Hello everyone,

I had been avoiding this lens for quite some time because I didn’t trust vintage wide-angle lenses. My collection of manual lenses topped out at 24mm, which I thought was the widest focal length with reliable quality. That was until I stumbled upon a Nikon 20mm f/2.8 AI-S for just $85!

To be honest, the lens wasn’t in great shape—it had fungus on the internal elements and oil on the aperture blades. But after a couple of hours of work, it looked (and worked) like new!

I did some quick test shots around my room, and to my surprise, the image quality was really impressive. I know this lens has been discussed to death here, but I’m curious—what’s your experience with it?

Should I hold on to it, or should I save up for a G or Z-series lens instead?

Cheers,
Zang

[Ian Watson]

If you are happy with the image quality then why not keep it? You can always add a more modern lens later, if you fancy.

[Zang]

Hey Ian,

Good point! My opinion was just based on the four shots I took in a dimly lit room. I’ll definitely put the lens to real-life use when I get the chance. With winter being a bit dull, though, it might be a little while before I can really test it out and that was why I asked for your opinion on the lens beforehand

Cheers!

[Akira]

If you find the image quality of your sample is impressive, I would say you were really lucky.

While I was using nikon cameras (film or digital), I've never encountered a single decent sample.  All I tested showed unusable corners even stopped down to f11.

All other 20mm lenses I've used (20mm f3.5 UD, Ai 20mm f4.0, Ai 20mm f3.5 and AF-S 20mm f1. were far superior and offered satisfactory images.

[Zang]

Thanks, Akira!

I’ll find a good brick wall and take a closer look at the corners of the image. My initial positive reaction might have been a bit premature, it could end up proving me wrong!

Cheers!

[Airy]

If you do not shoot brick walls, you will like its small size. It can pass for a standard lens and help you shoot interesting street views (I know, that's unethical but some rare people deserve that).

I always found its wavy distortion difficult to handle.

The 20/3.5 AI is definitely the better alternative (and even smaller) but that is no reason to throw away the 20/2.8.

I made no side-by-side comparison with the Viltrox 20/2.8 for Z mount, but the latter does not feel superior (even though its wavy distortion is less conspicuous). The old 20/3.5 UD better but needs to be stopped down.

[Nasos Kosmas]

I have the  20/3.5 -very small- in very good condition that’s OK in the digital age, but I have a lot of time with no use.
24-70/4 is too good with Z8 to pass.
But 20/2.8 is a nice choice to have

[Birna Rørslett]

Originally I purchased the 20mm f/2.8 for use in an underwater housing, but I have put it to good use in a lot of other settings as well. The lens is pleasant to use, foucs is smooth, and build quality fells sturdy like the other Nikkors of the same vintage.

I suspect it can get out of alignment if dropped, as there is a CRC group inside. Barring that adverse impact, the optical quality is pretty good. It was an excellent combinstion with my Df. Also performs very well in IR with my D5300. Apparently I haven't yet tried it out on my Z5 for IR., but that sitation can easily be rectified.

[Zang]

If you do not shoot brick walls, you will like its small size. It can pass for a standard lens and help you shoot interesting street views (I know, that's unethical but some rare people deserve that).

I always found its wavy distortion difficult to handle.

The 20/3.5 AI is definitely the better alternative (and even smaller) but that is no reason to throw away the 20/2.8.

I made no side-by-side comparison with the Viltrox 20/2.8 for Z mount, but the latter does not feel superior (even though its wavy distortion is less conspicuous). The old 20/3.5 UD better but needs to be stopped down.

Being curious, I decided to do some more test shots to compare the Nikon 20mm f/2.8 with my old Fujifilm 14mm f/2.8, and I made some interesting discoveries:

Both lenses set at f2.8.

Near minimum focusing distance (MFD):
a) Center: The Nikon 20mm looks way better than the Fujifilm 14mm—sharper and more contrasty.
b) Extreme corners: The Nikon 20mm looks bad here. Even without my glasses, I can tell the Fujifilm outperforms the Nikon in the corners. In fact, the Fujifilm seem to be sharper in the corners than in the (its own) center!
c) 25% diagonal edge: The Nikon performs very well in this area.

At 2.5m distance:
a) Center: The Nikon still holds up well, and the center still seems to be better than Fujifilm. This time the Fujifilm looks better overall, though its contrast is still a bit lower than the Nikon’s.
b) Extreme corners: The Nikon is just as bad as it was at MFD. The Fujifilm remains very strong in the corners, though slightly worse than it was at MFD.
c) I got tired at this point and didn’t bother checking the 25% edge.

Please note that the test might be unfair, tilted in favor of the Nikon, as is was conducted using two different cameras (FF vs APS-C).

Cheers!

[Birna Rørslett]

Curvature of field needs to be taken into consideration. You might have not gotten the CRC group in alignment when the lens was cleaned and reassembled.

[Zang]

Curvature of field needs to be taken into consideration. You might have not gotten the CRC group in alignment when the lens was cleaned and reassembled.

I was very careful and used my own method of marking and measuring to ensure everything was put back exactly the way it was. That said, bad things can happen sometimes, no matter how careful we are.

I tested the lens at f/2.8, and so far, the results are in favor of the Nikon. Based on that, I don’t see any reason to think the lens is misaligned.

[Zang]

...When I said Nikon looks bad in the corner, I really mean "much worse than Fujifilm". The corners from Nikon were not that terrible to ruin the photo at all, and I was talking about the extreme corner.

[Birna Rørslett]

Just a couple of random 20/2.8 shots. (Crete, 2017 when I met NG member Elsid in Chania). The 20 Nikkor does well in visible and IR.

[Zang]

Thanks Birna, the photos look really good!

[Zang]

When I said I made interesting discovery, I meant I was surprised Nikon outperforms the Fujifilm at f2.8 in center in different distances. Based on the reviews on Youtube, Fujifilm is said to be an excellent performer "at any settings"