"R.H." wrote:

276 looks like a shutter (to an old camera? film equipment? I dont know)

It's not a shutter, but it is part of a camera.

The shutter is behind the iris. The iris is first opened to the
calculated/selected F-stop, then the shutter opens briefly.

What we're looking at here is the iris.
--
Patrick Hamlyn posting from Perth, Western Australia
Windsurfing capital of the Southern Hemisphere
Moderator: polyforms group )