Nikon 20mm f/3.5 AI/AIS Lens Review

Background

Not only do we want to look at lenses for use on the newly released Nikon Z series mirrorless cameras, but we can also use these vintage AIS lenses on the Nikon Df.  There are also some modern DSLRs that are capable of using these manual focus gems.

Looking for something on the wide end, one of our local camera stores had a nice copy of the Nikon 20mm f/3.5 AIS.  How does this lens, released between 1977 and 1984, hold up today?

Let's find out!

Olympus PEN-F
1/100, f/5.6, ISO 200

Handling/Size/Weight

This is a small lens.  Smaller than the newer Nikon 20mm f/1.8 AF-S.

You've go an all metal lens on your hands here.

It is easy to find the aperture ring and differentiate it from the focus ring without even looking at the lens.

I must say that there is something very satisfying when using a manual focus lens.  While the more modern Nikon AF-S, full time manual focus override, lenses are more convenient - there is something quite different about the way that Nikon made their AI/AIS lenses.  Manual focusing is satisfying, and just feels right.   The focus ring is dampened, but only really moves when you want it to.   It feels so smooth and the throw is such that getting precision and accuracy is almost effortless.

The aperture ring has clicks for each setting.  f/3.5 and f/5.6 are marked on the lens, but there is a detent you'll hit right after f/3.5.   That will put you on f/4.  That setting is not marked on the lens, but the Nikon Df indicates the aperture when used.

Speaking of the Df, the lens mounts perfectly and handles well on my favorite DSLR.

Since the size is so small, the Olympus PEN-F or EM5 Mark II can use this lens adapted with ease.

Nikon Df
1/160, f/8, ISO 100

Weather Sealed

Not on this guy!  An old AIS lens.

Nikon Df
1/320, f/4, ISO 100

Image Quality

While it probably is not up to speed in relation to the thousand dollar state of the art Nikon lenses, this one can perform quite well.

One thing I'd like to point out and I find this to be true for all Nikon manual focus lenses that I own:  There is a potential for the aperture ring to move slightly past the widest setting.  When this happens, it degrades a image quality quite noticeably.

So, for this lens, you can turn the aperture dial just to the right of f/3.5.  I first captured this example on the Nikkor 135mm f/3.5 Q lens.  That review is linked to the left and it is shown in the first set of images.

I mention this as it is easy to do accidentally.  I just want everyone to be aware if it.  It may be normal, but those may not know could appreciate the heads up.

IQ - In a word, it works very well to capture crisp images.  I find that wide open is not it's strongest suite, although it is by no means unusable.  Even going to f/4, you could shoot there all day long and be happy.   The lens is sharp, but I would not call it bitingly sharp.

It does fall off in sharpness from center to the edge at wider apertures.  Shooting this lens on the Oly PEN-F, you get a 40mm field of view and the sweet spot of the lens all the time.

Shooting on the Df, you'll appreciate using it sot between f/4 and f/11.

I did not notice any real distortion on this lens either.  There are plenty of brick walls in the sample images here and none of them were corrected.  This is straight out of the camera stuff here except for some exposure tweaking

As I usually do, here are images to let the lens speak for itself.

Nikon Df
1/500, f/5.6, ISO 100

Nikon Df
1/125, f/8, ISO 640  

Nikon Df
1/125, f/4, ISO 140

Nikon Df
1/125, f/4, ISO 320 

Focusing

This is manual focus all the way, but since it was made to be manual focus, working the ring is a satisfying experience.

On the Df, the AF confirmation point worked well...better when using the middle point, especially if shooting at f/5.6 or smaller apertures.   You can always start shooting wide open,then close down the aperture after you got the focus nailed down.    I found that I did not need to do that much and is not how I generally shoot.

On the Oly PEN-F, focus peaking worked well with this lens and made it super easy to dial in.  You may be asking why the dual testing?  Simply put, I wanted to see how this lens might feel in use when I get the Nikon Z6, which should be in our hands come sometime November 2018.

The focus throw is good and you can go from close focus to infinity with not much movement.

What you also have going for you is that 20mm depth of field is generous, even at f/3.5, that when shooting further away subjects that say, 3 ft, you can just put the lens to infinity and shoot away!

Bottom line here, is that if you've ever used a Nikon manual focus AI/AIS lens, you know what to expect here.  It is all good!

Nikon Df
1/60, f/4, ISO 450 

VR

No VR in the lens, but used on adapted cameras like the Olympus PEN-F with IBIS, you do now have the ability to take advantage of it.  Even the new Nikon Z mirrorless cameras have in body image stabilization that will work with this lens.

We are looking forward to testing this lens out on the Z6.

With our time using it on the Olympus PEN-F, we set the focal length for the IBIS to use and off we were.   No issues, whatsoever.

Nikon Df
1/60, f/8, ISO 5000 

Bottom Line

Not much is thought of manual focus lenses in this age, but i think people forget how easy it is to work with them once you give them a chance.  The 20mm is helped by having a generous depth of field to help get things just right.

Another reason to give these older lenses a chance is the newer technology in the camera bodies.  Here, we have punch in focusing and focus peaking when adapted to either a Micro 4/3, Fuji, Sony mirrorless camera as well as the newly released Nikon Z cameras.