Self-capping

Glossary Terms

A shutter is self-capping if it excludes light during the process of cocking it. The term may be applied to either leaf or roller-blind shutters, and there are examples of either type that are not self-capping. If the shutter is not self-capping, then the film or plate must be protected by some other means while the shutter is tensioned; a lens-cap or the dark-slide of the plate-holder.

There is also an unrelated term capping, which is a fault that may occur in roller-blind shutters, such that the second blind catches up with the first during exposure.