Shutter reliability in the cold

[Hening Bettermann]

Hi!

An employee of Calumet in Hamburg told me of a photographer who had experienced that his Compur shutters striked in very low temperatures (-30 degrees Celsius), wheras the Copals survived.

In less extreme cold temperatures, say -15 degrees, shutters could be thought to become inaccurate without downright striking. This might stay unnoticed by the photographer in the field.

Are there any experiences/data about this, in particular: can the difference between Compurs and Copals be confirmed?

Hope you all have it nice and warm - Hening.

[Steve Hamley]

Hening,

Not enough information really. Most Compurs of the Synchro type would probably be 30 years or more older, so when was the last CLA done on these shutters? It certainly doesn't take cold weather for old grease to cause problems in shutters; I've had many a shutter cleaned that did not work well at room temperature.

I haven't had my Synchro Compurs out in freezing Farenheit (0 C) temperatures for very long but I would think that a shutter recently serviced with modern lubricants would work well.

Steve

[John D Gerndt]

Kodak recommends removing all lubricants in a shutter that is destined for very cold weather work. I don't know if they still have their information available on extreme cold weather work but a Google search might turn something up.

[John Layton]

Of the four Copal shutters present for this test (go to http://www.laytoncamera.com/ewtest.html ) three of them did remarkably well - and one faltered a little but never froze completely. We're talking zero to twenty below zero F, for hours on end, before factoring in wind-chill!

[tor kviljo]

Having used a lot of different shutters, and have had to open & sometimes fix a few also, I will say that the modern Copals seems to be made to run dry, i.e. w/o lubrication, whereas the compurs were (at least earlier) lubricated. The sound of a Copal compared to a compur confirms this to a degree. That a shutter is supposed to run dry is nothing special, ILEX'es were also made that way, being slow & unreliable when lubricated. The low milage (# of shutter-activations) a ordinary LF shutter will se during its life-span makes this (running it w/o lubrication) sensible it it benefits accuracy. Lubrication will be an issue with high-volume-work studio-shutters as the sinar-copal & Horseman ISS though.

[octagon]

Greetings from Montana

I can attest to a cold weather test just experienced this morning. At 6:30 a.m. I was at Two Medicine Lake in Glacier National Park. My shutter is a Copal that has worked well for me. However, one must be very careful in cold weather. I took my camera from a warm camper to the very cold day. The resulting condensation rendered the shutter totally unreliable. Apparently the moisture was freezing. Had the camera been in ambient temperature overnight I am sure it would have performed well. The same thing happens to the scopes on hunting rifles all the time. It is very difficult to find a lubricant that is not adversely affected by extreme temperatures. Condensation is going to happen no matter what in extreme temperature changes. I found that going to the bulb setting was the only way the shutter would function. I just developed the film and got some good shots.
Jerry

[Hening Bettermann]

Thanks to all of you who respnded! - The bottom line, as I draw it for myself: If Kodak recommends de-lubing shutters when they are to work in the cold, and Copal shutters are designed to run dry in the first place, whereas Compurs are normally lubed, then it makes sense to believe that Copals will do better in the cold. - Good light! - Hening.

[Hening Bettermann]

I found this one, too:

www.largeformatphotography.info/lfforum/topic/497546.html

Kind regards -