Synchronizing Contact

DEFINITION:

An electrical contact which operates by interlocking with the opening and closing of the shutter so that the light from a. flash is applied over the entire picture area.

DESCRIPTION:

M-contact: This contact is for class M flash bulbs. With a lens shutter, this contact operates so that current flows 13 to 19 ms. before the shutter blade opens 80%. With a focal-plane shutter, current flows 7 to 15 ms. before the slit center crosses the center of a picture.

FP-contact: This contact is for class FP flash bulbs. This contact operates so that current flows 15 to 20 ms. before the film is exposed during travel of the 1st shutter curtain.

X-contact: This contact is for an electronic flash and class ME flash -bulbs, when the delay time is set to almost zero. The X-contact of a lens-shutter camera is so constructed that the switch is turned on simultaneously when the shutter blade opens fully. The X-contact of a focal-plane shutter camera is so constructed that the switch turns on when the 1st shutter curtain clears the film area completely.

Hot-shoe: An accessory shoe with the electrode directly connected to the trigger contact of an electronic flash. With an electronic flash directly connected to the hot-shoe, flash-synchronized photography is possible.

In addition to the synchronizing contacts which synchronize shutter operations with the associated flash, some recent electronic cameras are equipped with other contacts such as one which automatically sets the shutter speed in response to the aperture value suited to flashphotography, and one which displays charge completion of the electronic flash capacitor.