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1-5. Synchronization

The camera has two synchronizing circuits; one with adjustable delay for Hash bulbs, and one without delay for electronic flash. A precontact switch for each circuit is interconnected with the shutter release. During a portion of the camera winding cycle the synchronizing contacts are closed, but the precontact switches are closed only when the shutter release knob is depressed, and premature firing is prevented. The synchronizing circuits, one side of which is grounded, terminate in synchro outlet plugs on the rear of the camera top plate. The flash bulb outlet is identified by a bulb symbol, and the electronic flash outlet by a lightning stroke symbol.

a. Flash Bulbs. Flash bulbs require a period of time between ignition and usable light output. To provide this delay the synchronizing circuit must be closed before the first shutter curtain has started to uncover the film aperture. The delay between closing of the circuit, and the entry of the first curtain into the film aperture, must be varied in accordance with the shutter speed selected.

PRE CONTACT S1


Figure 1-13. Flash Bulb Circuit, Contacts Open.

(1) Delay mechanism (fig. 1-13). A synchro cam, on the shaft of the speed cam, positions the synchro adjusting lever. The cam brings the lever closer to, or further from, the contact arm as the shutter speed dial is adjusted.


Figure 1-14. Flash Bulb Circuit, Contacts Closed.

(2) Bulb circuit. The contact arm cam (fig. 1-14) on the main shutter roller assembly, rotates when the shutter release knob is depressed. Rotation of the cam moves the spring-loaded contact arm toward the synchro adjusting lever and closes the circuit. When the first shutter curtain has traversed the film aperture, the high point of the contact arm cam is resting against the contact arm. This moves the arm away from the synchro adjusting lever and opens the circuit.



b. Electronic Flash. Electronic flash, is in effect, open flash. The first shutter curtain must clear the film aperture, and fire the flash, before the second curtain enters the aperture. The highest shutter speed at which the film aperture is completely uncovered is 1/50-second. This setting is indicated by a lightning stroke symbol on the shutter speed dial.

PRE CONTACT S3


MAIN CONTACT S4 Figure 1-15. Electronic Flash Circuit, Contacts Open.

(1) The synchronizing contacts are located near the bottom of the main shutter roller assembly. The contacts are open when the camera is wound (fig. 1-15), and closed when released. (fig. 1-16).


Figure 1-16. Electronic Flash Circuit, Contacts Closed.

(2) The first shutter curtain, after clearing the film aperture, operates the shutter brake. The lower actuating plate of the brake presses an insulated pin (fig. 1-15) against the long contact spring. The long spring moves against a short contact spring and closes the circuit (fig. 1-16). When winding, the shutter brake is released, and the lower actuating arm moves back opening the contacts.



1-6. Baseplate

(Fig. 22)

In addition to its obvious function of providing access to the camera interior, the baseplate secures the hinged back in closed position, provides a tripod bushing, guides the take up spool, aligned the film with the film advancing sprocket, and opens the metal film magazine.

a. Film Positioning Disc. The film positioning disc has cut-out sectors which engage the film loading prongs. The disc serves as a bearing for the prongs and aligns the film with the film transport mechanism.

b. Lock Assembly. The baseplate lock assembly secures the baseplate to the camera and opens the metal film magazine. An angled stop limits rotation of the lock assembly and releases the retaining spring of the metal magazine.

(1) The locking plate is slightly wedged shape. When the lock is turned from the open to closed position, the plate engages a locking bar on the cameras inner housing. The wedge shape of the plate pulls the baseplate tight to the camera body. Two projections on the locking plate strike the angled stop and prevent rotation of the lock beyond the open or closed position.

(2) When the baseplate is mounted on the camera, the curved edge of the angled stop pushes back the magazine retaining spring and unlocks the magazine. A groove in the locking plate engages the magazine inner shell knob. When the baseplate lock is turned to the closed position, the magazine inner shell is turned to its open position. Turning the lock to its open position closes the magazine. Removing the baseplate reengages the magazine retaining spring, and locks the magazine in the closed position.

1-7. Hinged Back

(Fig. 23)

The hinged back, in addition to opening for camera loading, also carries a pressure plate and studs for positioning the film.

a. Pressure Plate. When the hinged back is closed, a spring pushes the pressure plate against two outer film guides on the inner housing. The film rests between the outer guides and on the inner film tracks in the film plane. This provides a breathing space and assures smooth transport of the film.

b. Film Positioning Studs. When the hinged back is closed, the positioning studs rest against

the outer edges of the film. This holds the film perforations in engagement with the sprocket wheel teeth.




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