DIY Possibly useful source of pre-made irises

Folks, I was back stage at the Whitaker Center in Harrisburg, PA last night, (my child's in a ballet this weekend) and saw a huge file cabinet of gels for fixing light colors and on the desk nearby a 3--4" diameter manual Iris (18 thin steel blades) for adjusting the stream of light coming out of a stage light. Looking at it got me to thinking of those of you who think of making your own lenses from loose elements and/or want to put an iris on larger projection lenses. I've built a couple sets of waterhouse stops from cardboard and sheets of plastic etc. because I, while I'm reasonably patient, I just couldn't see to making an iris and calibrating it. I asked one of the stage hands about this iris and they said that they thought they weren't too expensive 50-100$. I believe the key words are "source 4 iris." Hope this is helpful.

I've been using one for a variable burning tool in the darkroom for years. They're about $100. I work in the film industry and got mine for about $100 less than that from a damaged fixture that was being thrown away.

The largest lens I use is a Gundlach Radar f:4.5. The lens elements are set in a Betax No. 5 Shutter. It accepts a lens barrel that is 73mm in diameter, and the iris opens from 4mm to 55mm. I believe the Betax shutters are also available in smaller sizes. Just a thought.

When I saw the pictures on the web I immediately thought !Universal lens mounting clamp!