The Compound shutter is a mechanical leaf shutter for photographic cameras introduced in the late 19th century, usually used between lens components. A typical Compound shutter may have settings for T (Time), B (Bulb), and times from 1 second down to 1/100th or less.
Unlike later mechanical shutters such as the Compur which use a clockwork mechanism, shutter timing is achieved by releasing air from a small cylinder typically mounted horizontally at the top of the shutter through a small aperture. A cam turned by the shutter speed dial positions a piston in the cylinder to provide the correct exposure. When the shutter release is pressed the shutter opens and air in the cylinder is gradually released, letting the piston move; it closes the shutter when it reaches the end of its travel. The piston travels for a very short distance at the higher speeds, making their accuracy very sensitive to the precise manufacturing of the cam; lower speeds are more reliably accurate.
Compound Shutters for Large Format Photographers
Famous quotes containing the words compound and/or shutter:
“He tries by a peculiar speech to speak
The peculiar potency of the general,
To compound the imagination’s Latin with
The lingua franca et jocundissima.”
—Wallace Stevens (1879–1955)
“And there is nothing in the eye,
Shut shutter of the mineral man
Who takes the fatherless dark to bed,
The acid sky to the brain-pan;
And calls the crows to peck his head.”
—Allen Tate (1899–1979)