View Full Version : Universal lens mount iris

24-Dec-2009, 07:20
Hi all,
I've seen several of these offered for sale both here and on ebay. I'm curious as to how they are used. I take it that they are used to mount a lens to a lensboard - not act as the lens's iris? Can someone explain what type of lens is used and how it is secured to the iris? A picture or link would be great. Thanks.

Ole Tjugen
24-Dec-2009, 07:28
Any lens can be used, and the iris is what secures it to the camera.

The iris has a lot of strong steel blades, which are closed around the lens barrel and then locked in place by tightening a knob. With most lenses this is more sufficient to keep them stable during exposure, although I do add an extra support when using my 840mm f:8 in this way - the barrel is too wide to be "clamped", so I can only mount it by the threaded end which puts all the weight in front of the camera...

24-Dec-2009, 08:32
Keep in mind, you need a pretty large lensboard, and a robust front standard to handle a steel iris and big lens.

erie patsellis
24-Dec-2009, 09:07
Given the silly prices lately, and regretting selling mine, I found an iris from a fresnel projector spotlight in the local theater's "parts" pile. Stouter blades than most mount irises I've seen, and with some washer shims, should be perfect, now to figure out an effective lock, as I really don't want to watch some of my good barrel lenses dropping off..

24-Dec-2009, 10:07
Thanks for the replies! So it seems like the iris blades clamp around the lens barrel or mounting threads and the two knobs on either side secure the blades from slipping. Looks kinda Rube Goldberg-ish but I can see that it would be handy if you had several barrel lenses or lenses w/out a mounting flange. My curiosity has been satisfied. I agree the prices seem out-landish but demand for no-longer-made things does that.

Ole Tjugen
24-Dec-2009, 12:36
Somewhere here there should be a picture of my Anniversary Speed Graphic 4x5" fitted with a small Universal Iris Mount. It's the only one I've seen that is small enoughfor a "normal" lens board, I found it by accident in a big box of "junk" I had bought for the nine good cable releases I knew was in there...