CAM(OPCS)		Optical Printer Control System		CAM(OPCS)

    NAME
        cam - shoot frames on the camera

    USAGE
	cam [value]          # run camera so many frames fwd or reverse

    EXAMPLES
	cam 12               # run camera 12 frames forward
	cam -12              # run camera 12 frames in reverse
	cam 54'11            # run camera 54 feet 11 frames
	cam >-32             # run camera TO counter frame -32
	cam >34'8            # run camera TO counter 34 ft 8 frms
	cam >(108/(10+2))    # run camera 9 frames (See MATH(OPCS))

    DESCRIPTION
	This command will shoot frames on the camera at the current shutter
	speed set by SPD(OPCS). 
	
	The value indicates the relative number of frames to shoot. 
	Negative numbers shoot in reverse.

	Values can also be specified in foot/frames or as a mathematical
	expression (as shown above).

	If the value is directly preceded by '>', this tells the camera 
	to 'go to' that absolute position on the camera counters.

	To do fast windoffs that don't involve exposing film, use SEEK(OPCS)
	which uses the camera's slewing speed.

    FADE/DX
	If there are any pending fades or dissolves, the fader will FIRST
	move to its next position before the camera exposes a frame.

    AUTOFILT/FEED
	If AUTOFILT(OPCS) is enabled, the camera will first expose the filter
	in the gate before moving the filter wheel. (As with the projector,
	when the system is idle, the frame in the gate is /about/ to be shot)

	If FEED(OPCS) is enabled, the motors will /first/ move to position
	before the camera exposes a frame. (Similar to fade/dx)

    ALLSTOP
	Hitting the ALLSTOP button, usually the (`) key, will halt the
	motors at the nearest frame. ALLSTOP is safe during shooting; 
	it does not affect exposure, and always leaves the shutter closed
	after stopping. The allstop key can be redefined by ALLSTOP(OPCSDEFS).

    BUCKLE/VIEWER
	The camera WILL NOT RUN if the buckle is tripped. When exposing film,
	it also won't run if the viewer is open. If either condition occurs
	while the camera is shooting, the motors will stop with an error at 
	the nearest frame, similar to ALLSTOP.

	If 'hardware no' is in effect, the buckle/viewer state is ignored,
	so that the OPCS software can run on remote computers that are not
	pysically connected to an optical printer.

    TENSION MOTORS
	Before the camera or projector move, the appropriate tension motors
	are enabled, to ensure take-ups are in correct modes for film motion.

    COUNTERS
        The default 'big' frame counters (See BIGCOUNTERS(OPCSDEFS)) are
	limited to 6 digits. If a counter clocks above 999,999, or below
	-99,999, the display recycles to zero. This is only true of the 
	display..the software still keeps track of the real position.

	This is NOT the case if 'BIGCOUNTERS' is disabled; numbers in the 
	'small counter' display will not be clipped. Disable BIGCOUNTERS
	in the opcsdefs.opc if you need frame counts above 999,999.

    SEE ALSO
        -- Operator Commands (OPCS) --
	PRO / CAM  - run frames on the projector / camera
	RAT, REP   - tandem shooting (interlock)
	RES        - reset computer's pro/cam counters to new values
	CHK        - check if the pro/cam/shu counters are at certain values
	SEEK       - run the camera/projector at slewing speeds
	FEED       - feed motion control moves to motors every camera frame
	VELREP     - special purpose velocities for tandem shoots (eg. YCM)
	AUTOFILT   - enable/disable the auto-wedging filter wheel

	SHU        - send the fader shutter to absolute position in degrees
	OPN, CLS   - open/close the fader shutter
	DXI, DXO   - set up an dissolve
	FDI, FDO   - set up an fade

	MATH       - math expressions (for use in frame specifications)
	MOTORS     - enable/disable the motor hardware for debugging scripts

        -- Setup/Definitions (OPCSDEFS) --
	SPDINTERP      - configure exposure speed interpolations
	SPD            - configure camera's default exposure and slewing speeds
	RAMP           - configure camera's maximum acclerations and velocities
        MRP            - configure 'maximum ramp pulses' for shutter motors
        PPR            - configure 'pulses per revolution' for a motor

	BIGCOUNTERS    - enable/disable the large counter display
	FPF            - configure the 'frames-per-foot' (16mm, 35mm, Vista..)
	BUCKLE, VIEWER - configure buckle/viewer sensor's ports and bitmasks
	TENSION        - configure tension motors
	ALLSTOP        - define the ALLSTOP key
	HARDWARE       - enable/disable using printer hardware

    ORIGIN
	Gregory Ercolano, Los Feliz California 12/18/89