"David Nebenzahl" <nobody@[EMAIL PROTECTED]
> wrote in message
news:4781e61b$0$16276$822641b3@[EMAIL PROTECTED]
> Just got finished rebuilding my old Rochester Optical
> shutter; seems to be working about as well as it was when
> new. But I have a few questions about it, directed to
> those who know a lot more about these old units than I.
>
> First of all, let me ID the shutter: it's a pneumatic
> shutter that says "R. O. & C. Co/Rochester, N.Y." on the
> top. On the bottom, on the aperture scale is "VICTOR".
> Speeds are 1-2-5-25-100 plus T & B. The lens says
> "SYMMETRICAL 5x7" on the side of the front element. Marked
> apertures are 8-16-32-64-256 (!!).
>
> My questions:
>
> 1. As I said, I think I got this working about as well as
> it ever did. The "slow" speeds (those below 1/25) seem
> extremely dependant on the condition of the (right-hand)
> pneumatic cylinder. With the cylinder (& piston) clean and
> dry, the speeds are noticeably much too fast. When I
> applied a little bit of oil, they slowed down appreciably.
> Seems as this is simply a fact of life for these types of
> shutters; sticky oil, dirt, or cold weather is likely to
> have major effects on shutter speeds. Was the photographer
> expected to keep his or her shutter "in tune"?
>
Air brake controlled shutters were very common until
the invention (by Ilex) of the clockwork escapment regulated
shutter.
The air cylinder should not need oil. I suspect the air
leak is too large. I've forgotten exactly how the Victor
shutter is layed out and can't find a drawing but most air
brakes have a small leak at one end. Its possible the end
cap is loose or that the gasket has shrunk up. Some
air-brake regulated shutters, like the Compound, are quite
accurate and quite reliable.
> 2. Speaking of pneumatic cylinders, the shutter has two,
> one on each side. But the one on the left does absolutely
> nothing! There's even a hole at the bottom of the
> cylinder. Were there other models that actually used both
> cylinders? If so, perhaps they wanted to keep the
> appearance the same, so they kept the left cylinder even
> though it is non-functional. Can't think of any other
> reason to have it there.
>
The second cylinder is for an air release. The end of
the hose pushes over the nipple in the end and its operated
by an air bulb at the other. Many old shutters were made
this way even when they had fittings for a wire release. Air
releases are more flexible and can be longer.
> 3. The operation of the shutter--that is, how the operator
> uses it--leaves much to be desired. There's no provision
> for a cable release. The same lever is used for cocking
> (push up) and shutter releasing (push down). So the only
> way one would get good results with long exposures would
> be if one had a very steady hand (or a massive tripod, or
> both).
>
> The thing that doesn't seem right is that the shutter
> doesn't work correctly unless one keeps the lever held
> down until the shutter closes. If you release the shutter
> but then let go of the lever before the exposure ends, the
> shutter will stay open until you press the lever again. Is
> this the way these were supposed to work? (I guess I've
> been spoiled by modern shutters.)
I think there is something out of order, perhaps a lever
is in the wrong place. The shutter should trip with a push
and not close until the air brake finishes its travel. I am
sure I had some sort of information about this shutter but
will have to search for it. The shutter should certainly
latch on the T setting.
The Rochester Optical Company was eventually bought out
by Eastman Kodak and became the Rochester Optical Division
of Kodak for a time.
--
---
Richard Knoppow
Los Angeles, CA, USA
dickburk@[EMAIL PROTECTED]
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