View Full Version : Using Compund Shutters

Frank Petronio
6-Feb-2004, 11:48
Hi, I am the hopefully winning bidder on an older 250 Imagon mounted in a compound shutter. Never having used a compound shutter, what are the procedures and cautions compared to modern Copals? Thanks

Arne Croell
6-Feb-2004, 12:01
The main rule is: NEVER use (force) the cocking lever when using B or T. You have essentially four controls (looking at the front of the shutter): A small lever with three positions below the lens: the positions are T (right), B (center), and M for moment (left). The release lever is the one sticking out on the left side of the shutter. If the shutter is set to B or T you just use the release lever (or the cable release) to open or close the shutter. If you use instantaneous time (the M setting), you set the time with the dial at the top of the lens (next to the air brake cylinder), cock the shutter with the lever sticking out on the right, and release it with the release lever or the cable release. Note that when using longer times like 1s you need to give the shutter a little time before releasing, to move the air brake piston to its starting position. Not really a point when taking pictures, but something to keep in mind when checking it with a shutter tester, for instance.

Michael S. Briggs
6-Feb-2004, 12:06
Arne gave the answer. Not following the directions re not cocking the shutter in B or T modes can damage the shutter. S.K Grimes has a webpage with this info and some photos of a Compound shutter, including the innards of one: http://www.skgrimes.com/compound/.

Tito Sobrinho.
6-Feb-2004, 15:00
.... and never lubricate the air piston.

Walt Muller
6-Feb-2004, 16:13
I bought an older 250mm Imagon in a Compound shutter just like you did. But the one-second time was way off. I had to send the lens to Grimes (just before he died!). It came back in really fine shape. But I was told (not by Grimes, but by a respected person here in Phoenix) that the timing of the shutter was controlled by the lubricity of the oil in the piston! Anyhow, it is a great lens.

6-Feb-2004, 16:23
On the positive side, with my Compound at least, you need quite a lot of force to try and cock the shutter on T or B so it is not something you would do easily by mistake unless you were totally ham-fisted (no, I didn't take it to the limit - not even in the interests of science ;-) )

As implied by Arne's description, you need to set the shutter on T (or B with a locking cable release) to focus, and then switch to M for a timed exposure. - there is no separate focus lever.


Tito Sobrinho.
6-Feb-2004, 21:04
"... timing of the shutter was controlled by the lubricity of the oil in the piston!"

Fourteen years ago, I sent my Compound #3 to Ken Ruth (Photography at Bald Mountain) for a CLA. What follows is what he told me, #1 Never apply oil to the piston. Wannabe "technicians" like to do it. #2 Facing the shutter: the timing is controlled by gently rotating the little screw positioned at 1 o'clock.

I bought an used 5x7 Eastman View Camera #1 and with it, came an 120/2.7 Tessar mounted on the above shutter as well as a Protar Series VII mounted on a dial set Compur. I sent both shutters to him. The latter, I use on my 5x7 (4x5) Deardorff and the former, occasionally on my Wista 45.

Paul Moshay
7-Feb-2004, 01:25
<<#2 Facing the shutter: the timing is controlled by gently rotating the little screw positioned at 1 o'clock.>>

Tito, You are teriffic, I had sent my Compound to Steve Grimes, and with all the seperation, ala Sally Mann, and the decrepit condition of the shutter, he said it was a junker. So with nothing to lose, I took the shutter apart and fixed it ( I am a journeyman machinist so machines don't scare me) and now it looks and works just fine. The only item I missed was the regulating screw you just mentioned. The one second was a bit fast and your suggestion to adjust the little screw worked perfectly. Now one second is just that, within small variations of course. Thanks, Paul

Tito Sobrinho.
7-Feb-2004, 06:56
Paul, Ken Ruth also told me that a Compound shutter is well made and very reliable after a CLA.

I am glad I was able to help you resurrect the Compound, and keep it from becoming a paper weight.