AI-ing a Vivitar 135mm f2.3

[rbsinto]

I just bought a Vivitar 135 f2.3 lens and would like to AI it for use on manual focus film bodies other than my meterless F.
I've never done one before, but have read enough about it that it seems reasonably simple and straight forward enough to do (if one has the right tools).
My question is: has anyone here converted this particular lens, and could they give me some insight into any hidden snags or surprises I may encounter when I open this thing up.
Please and thanks,
Robert

 

[Dwig]

I haven't done that particular lens, at least I don't remember it specifically, but keep in mind that the vast majority of the tutorials out there apply to Nikkor lenses specifically. Nikkors are a bit different than most other lenses.

Nikkors have two attributes that aid in simple Ai conversions that other lenses don't have:

• The f/stop ring is thicker than most other brands.
• The f/stop ring extends back from the flange face by about 1mm whereas other brands generally are either flush with the face of the flange or expose a slight amount of the side of the flange.

These two differences mean that in most cases, you can't simply cut away part of the f/stop ring to leave an acceptable Ai tab. You have to add material to form the tab.

Back when I was doing custom conversions as a sideline I generally found that I needed to add an "L" shaped piece of brass to form a decent tab. I would drill and tap a hole in the f//stop ring to hold the tab.

 

[rbsinto]

I haven't done that particular lens, at least I don't remember it specifically, but keep in mind that the vast majority of the tutorials out there apply to Nikkor lenses specifically. Nikkors are a bit different than most other lenses.

Nikkors have two attributes that aid in simple Ai conversions that other lenses don't have:

• The f/stop ring is thicker than most other brands.
• The f/stop ring extends back from the flange face by about 1mm whereas other brands generally are either flush with the face of the flange or expose a slight amount of the side of the flange.

These two differences mean that in most cases, you can't simply cut away part of the f/stop ring to leave an acceptable Ai tab. You have to add material to form the tab.

Back when I was doing custom conversions as a sideline I generally found that I needed to add an "L" shaped piece of brass to form a decent tab. I would drill and tap a hole in the f//stop ring to hold the tab.

Thanks for the tip.
However, I've decided to let a pro camera repair person here in Toronto do it, as I don't want to mess up what is otherwise an excellent example of the lens