How to AI a lens?

Dec 17, 2008
Maryland USA
I was wondering if there is a step by step on how to AI an older non-AI lens on the net. I tried google and here in a search, but found nothing.

I've seen lots of nice non-ai lenses for very cheap I would like to get, but need to know where to grind the metal off the lens. I guess I could buy an already Ai'd lens and go from there. But was wondering if anyone knew of a step by step.
Jan 3, 2009
I think Mark (Bourbon Cowboy) has done it and he said it was really easy. There was a place in North Carolina that has a kit. I'll try to dig it up once I get home, but I'm sure Mark would know off the top of his head.
May 11, 2006
Naperville, IL
Looks like you are/feel pretty handy with tools which is why you are looking to do it yourself. If it were for me I would just send the lens to John White @ and be done with it. His charges are very reasonable and he does a thorough job on the Ai conversions. He comes very highly recommended through various sources.
Mar 23, 2009
Some notes

Tosh posted some very helpful links, and here are a couple of additions.
The job is very simple, but try getting a hold of a lens in poor condition for your 1st attempt.
Tosh's second link tells where how wide the relief has to be for a given aperture lens.
You can cut the metal easily with a file.
Do remove the aperture ring, there are usually 3-5 screws on the bayonet mount that will be either flat head or cross point. Removing the ring will keep metal filings out of the lens, and let you clean some of the dirt that accumulates over the years.
I usually search the web to see if someone has directions for a specific lens, sometimes a screw just anchors a spring so you should not remove it.
The cross point screws are different than phillips, they are JIS, so for a best fit it is good to invest in this special screwdriver.
If a screw resists removal instead of applying a lot of torque try heating the center of the screw a bit with a soldering iron, this will free up any screw locking compound that might be present from the factory. Sometimes it helps to heat the screw and as it is cooling down put a minuscule amount of oil on the screw head and let it sit a while.
I've done around a dozen now, and only one gave me trouble. I had a stubborn screw that needed heat and oil to yield.
Jul 11, 2009
very cool......THANX FOR THE RESOURCES!!!........If I am understanding this correctly....these conversions allow the use of older MANUAL focus lenses on the newer cams including the D300???

Latest posts

Links on this page may be to our affiliates. Sales through affiliate links may benefit this site.
Nikon Cafe is a fan site and not associated with Nikon Corporation.
Forum post reactions by Twemoji:
Copyright © 2005-2019 Amin Forums, LLC
Top Bottom