Handbook of High Speed Photography - IET Labs, Inc.

-1 vw T0TIP"
TO f
I+C "3
TRIGGER 1
CONTACTS [ | TO BODY (GROUND)^
-vw-
TO RING,
3-WIRE TELEPHONE PLUG- J BODY—-
PLUGS INTO INPUT JACK OF \ (GROUND)
FLASH DELAY
RING-
(
I TIP-
Ri = 33 kilohms, H-watt carbonresistor
R? = 33kilohms, J^-watt carbon resistor
Ra = 33 kilohms, }4-watt carbonresistor
C = 5 MF(50 v, dc) electrolytic capa
citor (note proper polarity)
Figure 5-9. Contact-delay circuit, for triggering the Flash Delay
by acontact closure with full range of time delay available.
tion settings are listed in Table 5-2,) Since the Strobotac delivers its
peak light intensity immediately upon triggering, the built-in camera
delay at "F" and WM" flash settings causes the Strobotron lamp to fire
before the shutter is fully opened. Consequently, the trigger signal
that will cause the Strobotac to flash must be delayed appropriately if
a camera equipped only with these synchronization settings is to be
used. Adelay of approximately 4 milliseconds, for example, should be
used with most inexpensive universal-focus cameras, as these cameras
are usually equipped for wF"-type synchronization.
Shutter
Synchronization
Setting
"X"; XS
"M"
TABLE 5-2.
Time Delay Required in Trigger Circuit
for Various Shutter Synchronization Settings
Approximate Time Delay Between
Contact Closure And Full Shutter Opening
0+1 millisecond
3 milliseconds, nominal;
5 and 2 milliseconds maximum and minimum
15 ±2 milliseconds
Fully adjustable synchronized shutters provide both a zero delay
and an adjustable delay range from 5 to 19 milliseconds.
The appropriate delay time for the shutter being used should be
roughly set into the Flash Delay by means of the DELAY control.
Then, while visually checking the shutter-flash synchronization, as
outlined in Section 4-7, make a fine adjustment. Again, consistent
synchronization should be observed before film is loaded into the
camera.
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