I'm going to share a bit of a sad story of mine:
Along with my grandfather's F2 Photomic I have a beautiful 50mm ƒ/1.2. But it's pre-AI.
I used it happily on my D70 (without metering) and then on my D300, and still do.
But I made a mistake.
It's a pre-AI lens. I did not know that until very recently. I though "AI" was the metal coupling prong that stuck out of the lens. It's not.
AI is still used today in D-type NIKKORs. It's the part that sticks out at the back of the aperture ring.
But I didn't any of that.
I unknowingly mounted an incompatible pre-AI on my wonderful D300. And I wrecked it.
I didn't even know, until I mounted my first D-type NIKKOR on my D300. It didn't work. Why? Because the camera's AI couple has broken off because of interference from my pre-AI lens.
This realization was hard on me. Please don't say anything about my camera; please don't ask me how I use my D-type NIKKORs on my camera. I got past my D300. It was hard, but I did it.
I forgave myself for this terrible, terrible mistake I made.
But this post is about the lens. Not the camera.
I don't want to make this mistake again. Ever. But my 50mm ƒ/1.2 is a beautiful lens. The results I've gotten from it have been astonishing.
But I simply can not mount it on my next camera. Can not and will not. I do not want to go through this again.
I've thought about getting it AI-converted. That would solve all my problems, today, and in the future.
But it destroys the original lens, and I'm afraid that it would also destroy compatibility with my F2 Photomic. I do not want either of those things.
What am I to do?