In article ,
Andy Dingley wrote:
On 18 Feb 2005 23:00:17 -0500, (DoN. Nichols)
wrote:

O.K. A complete shutter assembly, missing only the screw-in
front and rear lens elements.

Iris, not shutter. It's adjustable to control the aperture, not open &
shut to control exposure. An iris like this can't be fully closed,
for one thing.

I said "complete shutter *assembly*". That is shutter blades,
timing mechanism *and* iris diaphragm.

The iris is only part of it. Did you bother to look at his
latest set of images of that one item from many views? It has the
provisions for setting several (quite slow) shutter speeds.

The shutter happens to be open, so what was initially
photographed and presented in the puzzle was only the iris diaphragm,
but he has the whole shutter assembly there -- except for the lens
elements which screw in behind and in front of the iris and shutter.

Enjoy,
DoN.
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