[LargeFormat] Compund Shutters

[Richard Knoppow]

----- Original Message ----- 
From: "Stuart Phillips" <stuart.phillips@rcn.com>
To: <largeformat@f32.net>; <cocam@blueyonder.co.uk>
Sent: Tuesday, May 20, 2003 9:33 AM
Subject: Re: [LargeFormat] Compund Shutters


> Clive, I am sure you know this page, from the late Steve
Grimes' site. If
> not, this might help you:
>
> http://www.skgrimes.com/compound/index.htm
>
> Best
> ----- Original Message -----
> From: "Clive Warren" <cocam@blueyonder.co.uk>
> To: <largeformat@f32.net>
> Sent: Tuesday, May 20, 2003 4:21 AM
> Subject: [LargeFormat] Compund Shutters
>
>
> > Has anyone been inside a compound shutter? Mechanical
shutters hold
> > no mystery for me (except the Compur 0.0) but there is a
compound
> > shutter sitting here that needs a little TLC. Any tips
appreciated.
> >
> > Cheers,
> >         Clive
> >
    Not made clear in the photos is an adjusting screw for
the tension of the main spring. This sets the speeds. When
clean a Compound is a very reliable shutter. I am not sure
all had fiber shutter blades.
    Steve's page shows a complete disassembly of the
mechanism. Usually Compounds do not run well because the
piston has become gummed up. cleaning it with some lighter
fluid will free it up. Despite the seemingly crude air
piston regulator Compounds are more repeatable than Ilex
shutters. Perhaps that is why they were made for some
seventy years.
  BTW, the Compound is not unique in not needing to be
cocked for T and B. The Compur shutters before the compur
rapid were all like this. The ability to open and close the
blades at will is useful in two ways. One, you can leave the
speed dial where you want it and open the shutter for
focusing by setting the lever to T or B. Secondly, you can
use the shutter to make successive exposures, for instance,
to make a time exposure where something would interfere with
the image, for instance, cars going by the front of a
building. Or for "painting with light" in an interior. It
requires very little force to actuate the blades so the
camera is not disturbed.
---
Richard Knoppow
Los Angeles, CA, USA
dickburk@ix.netcom.com