Help me understand my shutters...

**Hovmod** · 5-Sep-2010, 01:42

Another newb question:
On my Sinar P setup, the front standard has a Copal shutter mechanism, which seems to work fine.
When I attach the Symmar 210mm, I have to use this shutter, which I noticed activates the aperture blades in the lens itself. So far so good. Works.

It's when I attach the Scheider 90mm Super Angulon I get confused...
It has a shutter/aperture itself.
So I guess I'm asking what's the preferred method to use? Do you use the lense's shutter or the Copal one? Is there a way to trigger the Lens shutter with the big main cable release?

I've been using the Lense's shutter/aperture, keeping the Copal open. The reason I ask is that I screwed up on my last images, and forgot that the Copal closes automatically if I keep the cable that runs from the film holder bits to the front one attached. Blank sheets.

Am I thinking wrong?

**Wade D** · 6-Sep-2010, 23:23

Keep the one in the front standard open and use the one on the lens. Or you could put the one on the lens to T and use the front standard shutter. Both methods will work fine. Just don't forget which shutter is in use. Also when using the front standard shutter for the 90mm you will have to make sure the f stop is at the correct setting.

**jackpie** · 7-Sep-2010, 02:05

The Copal shutter on your front standard is the Sinar Copal Shutter. Designed to work only with Sinar cameras, and has many advantages over regular "on lens" shutters, eg consistant shutter speeds with all lenses used, and some automation and ease of operation.

The ideal lenses to use with your Sinar Copal shutter are lenses mounted on Sinar DB or DBM lens boards. Your Symmar 210 seems to be one of these. These lenses do not have their own shutters and are designed to work with the Sinar Copal shutter.

Many regular lenses mounted in shutters can be still be used with the Sinar Copal Shutter by locking them open with their B or T setting, and setting their desired aperture on their shutters. Be aware that some regular lenses may project back too far and mechanically foul the Sinar Copal shutter preventing their use.

Alternatively the Sinar Copal Shutter can be locked open and the regular "on lens" shutter used. But as you have experienced the automated features of the Sinar Copal Shutter can work against you. The insertion of the film holder and automatic closing of the Sinar Copal Shutter have spoilt your shot using the regular "on lens" shutter. The solution is to remove the cable between the the back and the Sinar Copal shutter, or to remove the Sinar Copal shutter completely from the standard to use this kind of lens.