Converting old MF Nikkors

Bringing classics back to life.

Nikon’s Nikkor lenses, made through the early 1970s, were strangers to plastic. Brass and alloys were the order of the day, right down to that gorgeous scalloped metal focusing collar. These come with the meter coupling prong used on the old Photomic metering heads on the Nikon F and Nikkormat bodies of the era, redundant on modern digital bodies. But, while Nikon made their later lenses ‘AI’ (Auto aperture Indexing), these old masters will not fit a modern DSLR. A sector has to be milled from the rear of the aperture ring to permit fitting and to index the lenses’ maximum aperture if the metering system is to work correctly.

You can get a sense of what I’m talking about by simply feasting your eyes on my latest acquisition, a 200mm f/4 Nikkor-Q lens, made in 1971. Simply gorgeous to handle and behold, with optical quality to match. Markings are engraved and paint-filled, and of very high quality. The whole thing is a beautiful, thoroughly engineered tool.

They simply do not make them like that any more. The lens hood is built-in.

Here’s the rear of a Nikkor of that era before AI conversion:


Arrow denotes lip.

As you can see, the small lip protruding from the rear of the aperture ring does so all the way around. It prevents the lens from mounting on a modern DSLR body.

And here’s a Nikkor which has had the AI conversion done:


The arrows show the limits of the milled arc.

I own two such classic Nikkors, a 50mm f/2 and the 200mm f/4 above, and had both converted to AI specifications by John White of Ann Arbor, Michigan, a highly regarded source for such work.


Click the picture to go to John White’s site.

The turnaround time is about a week, and the cost $33 including shipping. Mr. White is polite, answers emails promptly and is a pleasure to deal with. After conversion, lenses work perfectly on my Nikon D700 body, though you have to remember to dial in the right ‘non-CPU lens’ setting if you want correct EXIF data stored with the image file.

And the cost of that mint 200mm gem? Would you believe $29? Yes, twenty nine dollars. With conversion and shipping the total cost came to $75.

1972 50mm lens on a 2012 body.

It’s not easy to describe the sensual pleasure of using these old lenses. The best I can do by way of analogy is to say that, after using their modern equivalents, it’s comparable to the difference in telling time on a mechanical watch compared to a digital timepiece. Both serve identical purposes but there’s only one you return to with eager anticipation and that silent thrill that has you thinking “Wow! Do I really own this?” Form and function are one.

These classics are abundantly available and, if you can live without VR and autofocus, worthy of serious consideration. You can be sure of two things. They will outlive you and they go for the price of a sushi dinner.

Obligatory snap of the long suffering Bert, at f/5.6.

Some people use a brick wall to test lenses. Chez Pindelski the test chart is none other than Bertram, the Border Terrier.

For more snaps taken with the 50mm Nikkor lens, click here.

For DIY instructions on AI conversion of old Nikkors, click here.