User`s guide

ARRICAM Accessories Quick Guide 01/2004, Page 9 of 24
Synchronisation of the camera to external sources
With the SPEED CONTROL switch set to SYNC, the SCB can synchronize the frame rate to an external source,
e.g. video signal, pulse generator or monitor. No sync function is possible when using a cable longer than 15
m/50 ft to connect the camera and SCB.
There are three different input signals that the SCB can accept.
1. A video signal can be fed into the VIDEO IN (BNC) connector.
2. The ARRI Pick-up Unit can be connected with the Cable KC 66-S (10m/33ft) to the SYNC IN (4 pin Fischer)
connector. The Pick-up Unit will sense the frequency of a CRT monitor when placed on or around it.
3. Any signal from 3 to 30 V with a frequency of 3 to 240 Hz can be input to the SYNC IN (4 pin Fischer)
connector. Pin 3 is SIGNAL, pin 4 SIGNAL GND.
Note:
If a signal is present on the VIDEO IN and on the SYNC IN connector, the VIDEO IN connector has priority.
Note:
In SYNC mode, the Speed Control Box will override the fps function of the Manual Control Box.
RATIO selector
The RATIO selector sets different ratios between input frequency and output fps. Use the table of examples
below to help choose the correct ratio for any given shot. Input frequencies can be from 3 - 240 Hz, keeping
in mind the top speed of the Studio (60fps) & Lite (40fps). For two seconds after the input frequency or RATIO
is changed, the FPS and SHUTTER displays show the input frequency and ratio respectively. If the input
frequency is present and valid, the FPS display will then show the output fps (indicated by an arrow). Other-
wise it will show “Syn”.
Setting Ratio Example Input Frequency (Hz) Resulting Output fps Notes
0, 5 - 9 1:1 24 24 (e.g. projector)
1 2:1 48 24
50 25
59.94 29.97 (NTSC video signal)
60 30
70 35
2 3:1 72 24 (e.g. computer monitor)
75 25
3 4:1 100 25
4 5:2 59.94 23.976 (NTSC video signal)
Note:
The shutter angle should be adjusted to 180° for all settings, except for the 5:2 ratio which should be 144°.
Other settings
Usually, set the VIDEO IN 75 switch to ON when feeding a video sync signal into the VIDEO IN connector.
In case the video signal is forwarded (T connector) to a monitor, try ON or OFF to see which works better.
• If you feed a PILOT tone to the audio recorder, check with the sound department if they need 50 or 60 Hz.
The PHASE setting determines the start of the exposure for each film frame in relation to when the image is
drawn on the video monitor. The result is the angled horizontal bar visible on the monitor seen through the
camera’s viewfinder. To prevent exposing the bar on film, the bar should not be visible through the view-
finder of the running camera. Try first the FIXED position of the PHASE (FIXED/MANUAL) selector; FIXED is
a phase value that works in most cases. If the horizontal bar is still visible, switch to MANUAL and use the
SYNC PHASE button to move the bar to where it is least visible. The camera remembers this phase setting
(the position of the bar) until the SYNC PHASE button is pressed again.
Note:
The exception to this rule is when shooting with the RATIO selector in setting 0 or 5 - 9 (1:1). In this case the
worse the image in the viewfinder, the better it will be on film.
Speed Control Box - External Sync