okay before anyone says it i am well away that these lens are viewed as noting above a paperweight but i got it free and thought i'd see what it coud do.
its an oscillio raptar F1.9 the 65mm version rather than the 75mm most other people talk about.
I want to mount it on a 3x4 pacemaker lens board, first question how do i get the large black plastic ring off the back? i'm presuming these were standard, i'll post photos later.
secondly what diameter hole whole will i need in the lens board?
i know theres some problem with these shutters not having a retaining ring, i'll probably just glue it.
any advice you can give would be brilliant.