View Full Version : Copal Bulb ?

27-Dec-2011, 00:32
I've looked it up with Google, and came up with some discussions on this forum, but the answers weren't clear to me:

What does "Copal Bulb" exactly mean ? I know what Copal is (I have several lenses with Copal shutters) and I know what the Bulb-setting means (all my Copal shutters have that setting), but why is this "B" specifically mentioned with several lenses on the KEH site ?

It gives me the impression that those shutters have ONLY a B-setting, but I can hardly see the use of that ...

Thanks for any enlightment,


27-Dec-2011, 01:01
I am almost sure that its a shutter with a B setting but not a T setting, but someone better informed will probably come along and set you more straight.

27-Dec-2011, 06:02
If you are looking at the KEH web site, it will not usually just be "Copal Bulb", but rather "Copal Bulb, Time". This, of course, means it has B and T speed settings, but in KEH-speak it means that it is a conventional Copal large-format shutter. If it says "Press", it is the self-cocking Copal shutter intended for press camera applications. I do not know if the Copal Press lens has a press-focus control--a different definition of "press"--that allows you to open the lens for viewing on the ground glass.

Some shutters only have the B setting, and not the T setting, including the Compur 00. That may also be true of the Copal Press shutters--I don't know. And there may be variations I've not seen--but I've never seen a conventional Copal view-camera shutter without a T setting and a press-focus control.

Rick "noting that KEH's descriptions seem not to have been created by large-format photographers" Denney

MIke Sherck
27-Dec-2011, 06:43
It gives me the impression that those shutters have ONLY a B-setting, but I can hardly see the use of that ...

Nevertheless... I don't know whether any Copal shutters have only a B setting and not a T, but other shutters certainly do. The ones I've had have all been older shutters and usually didn't have a way of keeping the lens open for focusing. You had to use a locking shutter release with the shutter on the Bulb setting. Eh, it worked.


27-Dec-2011, 07:39
There are shutters that have only a Bulb setting in addition to the timed settings. If you need a long exposure you use a locking cable release.

Copal may have made such products. I've never seen one, but I've certainly not seen all variants of the Copal shutters.

Inclusion of the Time function requires additional components inside the shutter, thus raising the price (or reducing profit margin) with little added value to potential purchasers.

- Leigh