Reliability of Compound Shutters

[Kevin Crisp]

I've only recently started using two lenses mounted in the pneumatically timed compound shutter. Both shutters are very old, but both were also just CLA'd by someone well respected. Both lenses would be a major pain to remount in something else, and the compound shutters are much lighter and smaller than other options. The problem is that both of my shutters became erratic in a very short period of time, meaning I got maybe one trip out of each before the speeds are off enough in places to make several stops' difference. And not reliably off, either. Am I just having bad luck? Are others of you using these and having them work reliably? Thanks, as always.

[Steve Hamley]

Kevin,

I'm guessing the service is at fault since both started showing the same problem at the same time, and the nature of the problem (inconsistently off). S.K. Grimes seems to think highly of Compound shutters.

http://www.skgrimes.com/compound/index.htm

I prefer Compounds over Ilex shutters, and I have 4 of them, a #3, #4, and two #5s. The #3 was recently serviced by S. K. Grimes and the others have not been serviced recently. All of them have consistent shutter speeds and are reasonably accurate, but of course the #3 runs like a fine watch. The #4 's 1 second is about 1-1/2 seconds, but the shutter was most likely made in 1939 according to the lens data for the lens that came in it - not too bad for 65 year old shutter. I have Ilex's that were made in the 50s and 60's that are unusable at longer speeds until they get a CLA.

Thanks!

Steve

[Bob._3483]

One thought: some people recommend waiting 5 seconds or so after cocking the Compound before firing it to allow the mechanism to settle.

Cheers,

[David A. Goldfarb]

I recently acquired my first lens in a Compound shutter. It needs a CLA for sure, but I was surprised by low level of vibration, I presume due to the air piston mechanism.

[Ernest Purdum]

Bob's suggestion is important, particularly for the slower speeds. Aside from this, your experience is unusual. If Bob's advice doesn't help. I think you should talk to the man that did the CLA.

[Bill_1856]

I have two Compound shutters, and have to wait 30 seconds(!) after cocking before they are consistant. Love 'em.

[Jason Greenberg Motamedi]

I have three Compounds and find them very reliable, although they are very sensitive to dust. As is mentioned, you do need to wait a bit between long shots (I find five seconds more than enough, 30 seconds seems crazy). I have found that with the Compounds after about three or four weeks following a CLA the speeds tend to drag out a bit, and then stabilize. Like Ilex shutters, the time-scale on compounds can be set to between times. So, if you have a shutter timer, like the $100 one from Calumet, you can mark exactly where the speeds are.The speeds I marked two years ago on my most used Compound, an no. 5, are still perfectly accurate.

[Jim Galli]

The piston that restrains the spring load travels the same speed in either direction. If it's set on one second, it will take one second after cocking to get to the end of it's travel. Waiting extra time won't hurt anything. All of the ones I have only became reliable again after taking the piston off the top and meticulously cleaning the cylinder and piston to a dry polished state and re-assembling. There's also a cam action that needs a light grease on the side of the cocking lever. They're particluarly straight forward and easy to work on if you're inclined that way at all.

[David G. Gagnon]

The compound that I used to own needed a settling-down time, too. I seem to remember just a second or two wouldn't do it. It took ten or more, if I recall. Also, I had spoken to Steve Grimes several years back, and he reminded me that the air-retard cylinder and piston was to be completely dry, but the end caps needed grease applied to the threads and gaskets to make a good, airtight seal. Even then it did not have very consistent firing times. I never did send it to him for a CLA, but should have.

Good luck.

DG

[Al W]

My first experience with an erratic compound was at a camera show. It wouldn't fired the same speed twice. I got a great deal on the lens, with a bad shutter, and sat it on the project shelf. When I got to it in a more relaxed setting it worked fine; then didn't once I started exercising it. After a while I realized it was the wait after cocking that made the difference. The plunger in the bulb has to have time to completely reset before firing.

By the way, you can speed a shutter up by running a cotton swab along your nose to pick up oil then run it inside the cylinder. This lubricates a dry cylinder enough to make the plunger move faster. To slow a shutter down do the same with light oil. The oil film setting on the surface of the cylinder wall makes the plunger air tight and slow it down. If the wrong oil is used in service, the shutter will have problems with hot and cold conditions.

Even if the timing starts to drift on this shutter it will be very consistent from shot to shot. Since I have several older shutters I invested in a hand held speed tester and check the lens I'm using in the temperature setting I'll be using as part of my setup. It only takes an extra minute.