Chapter 5 of "Instruction Manual for RB Super Graflex &c"
The Super D GRAFLEX Cameras have provision for built-in synchro nization of flash lamps, through the use of a battery case, reflector and connecting cord, referred to as a flashing unit. The mounting plate for the battery case is generally attached to the right front corner of the cam era body above the focusing knob. Slide the battery case in position and attach the connecting cord from the shutter outlet on the camera to a series outlet in the battery case, In the older GRAFLEX battery case, this is underneath the red push button switch which can be unscrewed, With the newer Graflite equipment, set the circuit controller at No. 1 and attach the connecting cord in the SHUTTER Outlet.
The GRAFLEX Camera provides a drop curtain setting providing a speed of approximately 1/5 second (see page 12). At this setting (curtain at "0" and tension at "H") a flash lamp will be fired while the shutter curtain is open. Determine the correct diaphragm opening for the flash lamp and the distance to the subject on the basis of a "Time" or "Open Flash' ' exposure from the table supplied by the lamp manufacturer, and set the diaphragm control of the lens accordingly. The length of exposure will depend primarily on the duration of the flash and in the case of SM or SF lamps (gas-filled), this will be in the neighborhood of 1/200 of a second. High Speed Electronic Flash Units can also be used with the Open Flash setting with those Super D Models having the simplified local plane shutter with speeds shown in Figure 6B.
Exposure will depend primarily on the duration of the flash and in the case of SM or SF lamps (gas-filled), this will be in the neighborhood of 1/200 of a second. High Speed Electronic Flash Units can also be used with the Open Flash - LOW tension setting with those Super D Models having the simplified local plane shutter with speeds shown in Figure 6B.
In the event that other lamps such as a No.5 Press 40, No.2, etc. lamps are used, the flash duration will be longer and low tension must be used to compensate for the ignition lag of the lamp. Low tension should also be used with relay operated high speed units, although high tension can be used with the zero delay high speed units. Do not use No.6 or FP-26 lamps.
Those 3-1/4 x 4-1/4 Revolving Back Super D GRAFLEX Cameras with a synchronizer socket on the shutter plate at the right side have the neces sary special curtain and mechanism to allow the firing of the large, long peak flash lamps such as the No.31 and 2-A lamps, in synchronization with the camera settings indicated below. Do not attempt to use the No.6 or FP-26 or other lamps, than those specified.
1/1000 (D-High) back in horizontal or vertical position.
1/400 (C-High) back in horizontal or vertical position.
1/200 (B-High) back in horizontal or vertical position.
The B, C and D curtain apertures are marked in black as a reminder that they may be used for synchronization. Do not attempt to synchronize with LOW tension with the B, C or D apertures, or with the A aperture at either HIGH or LOW tension. This aperture is marked in red as a reminder. To prevent accidental firing of the flasli lamp, be sure to dis connect the cord or remove the lamp before dropping the shutter cur tain from one aperture to the next larger (viz; from D to C) . The lamp will not be fired as the curtain is wound from B to D. Note: The earlier 3¼ x4¼ Super D Models with the synchronizer socket in the side of the camera do not have the necessary special shutter or mechanism to assure synchronization at any instantaneous speeds.
In view of the larger area of the film across which the opening in the shutter curtain must travel and the larger mass of shutter curtain as well as the length of useful peak of the lamps, it is presently impractical to attempt to guarantee synchronization with a wide range d instantaneous speeds even when the long peak flash lamps are used. Because of the length of time reguired for the curtain opening to pass across the film and the length of useful peak of flash provided by the G-E No.31 and Wabash No. 2A lamps, it is necessary to control carefully the location of the curtain aperture, so as to insure even exposure of all of the film. The shutter curtain of any camera will pack when wound tightly on the roller. The packing of the curtain controls the location of the curtain aperture with respect to the film at the moment the circuit to the lamp is closed and it thus has a marked bearing upon synchronization with the useful peak of the flash during the time that the curtain aperture passes across the film, Consequently in order to allow a slight margin of safety to compensate for slight variations and tolerance in camera shutters and the flash lamps themselves, synchronization can be guaran teed only at the 1/1000 setting, (D, H) with the back of the camera horizontal and the shutter curtain packed. To accomplish this packing the tension should be set at H, the shutter should he wound to the " 'D" position, and allowed to drop one position (to C) by operation of the shutter release lever at the right side of the camera. NOTE: Disconnect the connecting cord to prevent pre-firing of the flash lamp as the cur lain is packed. The curtain should be wound from C to D and released at least three times, following which the connecting cord may be plugged in and the exposure may be made with the expectation that the shutter will be properly packed, so as to assure synchronization.
SUGGESTED EXPOSURE TABLE
ASA Film Speed Range
Because of the many variables involved, Graflex does not supply any accessory device for synchronizing Graflex focal-plane shutters. Various attachments for this purpose are on the market, and their manufacturers should be consulted for all information regarding them.