AUTOFILT(OPCS)		Optical Printer Control System		AUTOFILT(OPCS)

    NAME
	autofilt - enable/disable the auto-wedging filter wheel

    USAGE
	autofilt [-nohome] [on|off]

    EXAMPLES
	autofilt on          # Enables auto-filter wheel movement,
	                     # sends the filter wheel to home position.

	autofilt off         # Disables auto filter wheel.
	                     # sends filter wheel to home position.

	autofilt             # Prints if autofilt mode is ON or OFF

	autofilt -nohome on  # Enables auto-filter wheel movement,
	                     # does NOT home or reset counter to zero.

    DESCRIPTION
	Sets up the filter wheel to move automatically each time the camera
	finishes shooting a frame. The filter wheel begins moving immediately
	after each exposure, while the shutter is closing.

	To shoot a 20x wedge:

	    autofilt on  cam 20  autofilt off

	'autofilt on' and 'autofilt off' automatically send the filter wheel
	to its home position (invoking 'home autofilt') and zeroes the 
	channel's counter. This can be disabled with the -nohome option.

    OPERATION
        'autofilt on' will do the following:

	    > Executes 'home autofilt' (unless -nohome is specified)
	      to home the wheel to a position that has NO FILTER.

	    > Zeroes the filter wheel channel's counter (unless -nohome
	      is specified)

	    > Like fades/dissolves, commands that involve exposing the camera 
	      (CAM, REP, etc) will first expose the filter in the gate BEFORE
	      advancing the filter wheel. The filter will NOT move during 
	      SEEK(OPCS) or GO(OPCS).

    SETUP NOTES
	It is assumed the filter wheel speeds have been configured to move to
	the next filter position quickly enough so that it stops before the 
	camera begins exposing the next frame.  See FILTER(OPCSDEFS) for a 
	full technical description.
	
    SEE ALSO
        FILTER(OPCSDEFS) - define channel to control a filter wheel

    BUGS
        The autofilter stuff was broken for a long time until OPCS 2.34b.
	Before that, any kind of wedge wheel stuff had to be done
	with GO(OPCS) commands mixed into shooting.

	Also, autofilt did not affect the filter channel's counters during
	shooting until OPCS 2.34c, where it now keeps count in steps.

    ORIGIN
	Version K1.12e+ Gregory Ercolano, Venice California  04/10/98