Mounting Vintage Nikkor on Nikon D90

I recently picked up an extra mint example of the vintage Nikkor 50mm f/1.4 prime lens on eBay. Judging by the serial number and the type, it’s most likely from the late 1960s or early 70s. This lens looks amazingly clean. Not only for its age, but clean. Period. It has not even a single rub mark on the barrel. It looks like it may have been stashed in the garage or in the attic for the past 40 years or so.

This Nikkor-S feels very solid and is built like a tank. The focus ring turns with a bit of dignified resistance – a feeling that’s missing from lot of modern plastic lenses. The aperture ring snaps into position with a confident click. Makes me want to just turn the ring back and forth just to feel the satisfying snap. It’s a beautifully constructed piece of equipment. I have no reason to doubt this lens will outlast my camera or any of my modern equipment.
Nikkor-S 50mm f/1.4

Nikkor-S 50mm f/1.4

Nikkor-S 50mm f/1.4


Unfortunately, any non-AI (or pre-AI) Nikkor lenses need to have its aperture ring filed down in order to be mounted on the Nikon F-mount. It’s a shame because this lens was in such mint condition – it broke my heart when the time came to perform the surgery on this little gem.

While a full AI conversion on pre-AI (or non AI) Nikkor Lenses is a common practice, it’s useless on the D90. Because the D90 does not have AI coupling ability nor will it meter with lenses made before Auto Focus (AF). However, I still needed to modify the aperture ring on the lens for it to mount properly. On the D90 lens mount, at about 8 o’clock, there is a switch that senses the minimum aperture. In my case, I don’t need this lens to interact with this switch. All I had to do was file away part of the aperture ring on the lens so it clears this switch. Otherwise, this switch will be crushed the moment you try to force mount the lens.
Minimum Aperture sensing post NikonD90

To do this I had to disassemble the aperture ring. I know from experience that manufactured goods from this era are put together in rather rustic fashion compared to the modern day consumer products. Don’t get me wrong, the build quality is superb but it’s just that the pieces – once you take them apart, it’s difficult to realize how they’re put together. This is in contrast to the modern day manufactured products where each pieces are designed in a way that it’s easy to see how they are meant to be assembled. This is probably so that an unskilled worker can assemble the pieces easily and quickly. Having said that, when working with a vintage piece you must remember how each piece came out otherwise you’d be lost for a very long time.
I used this as a guide. The example in the link uses a lens made in different year so the steps for removing the ring is slightly different.
Non AI Nikkor conversion

NIKON D90 with NIKKOR-S 50mm f/1.4

It was a nerve-wrecking experience but a rewarding one. Here it is, a Nikon D90 with a beautifully mounted Nikkor-S 50mm f/1.4. Note, there is no metering with this set-up. You have to guess or use the Sunny 16 Rule. But this isn’t a big deal with modern DSLRs since you can preview the exposure immediately. The focus is manual, of course. I have taken a few test shots with this lens and it does seems to create the infamous ‘dreamy’ look at wider apertures. Being fully manual (including metering), it probably won’t see many action other than still-life shots or portraits. I will post the results as soon as I do some proper shooting with this lens.
Nikon D90 with vintage Nikkor-S 50mm f/1.4


  1. Hi. I just want to know how and what’s the measure in modifying the said auto s 50mm 1.4. it seems that the guide link is not working. can you email to how? thanks in advance. I also have d90

  2. Hi,
    I recently purchased the Nikon 300mm f4.5 non-ai silver barrel for my D90
    Will I be able to use this ? I am aware i’ll loose metering and AF functions
    But still was it worth it for a 100 bucks ?
    Thaks in advance for your time
    Best wishes

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