FRANGE(OPCSDEFS)	Optical Printer Control System	     FRANGE(OPCSDEFS)

    NAME
        frange - configure the open/close positions for fades/dissolves

    USAGE
        frange [close] [open]         #  values are in degrees

    EXAMPLES
        frange 0 170        # normal for a 170 degree shutter

        frange 90 130       # for special Hicon film stocks 
                            # (fades/dissolves go from 90 to 130
                            # degrees)
    DESCRIPTION
        FRANGE(OPCSDEFS) allows the user to specify the open and closed
	positions [in degrees] for the FADE/DISSOLVE commands.
	
    NOTES
     ***********************************************************************
     ** This command does NOT affect the OPN/CLS commands, which still go **
     ** full open/full closed.                                            **
     ***********************************************************************

        The fader must be in the correct start position for a fade/dissolve
        to occur without giving an error. If the FRANGE is set to 90/150,
        then the fader must be at 90 degrees before doing a FDI/DXI, and
        150 degrees before doing a FDO/DXO.
	
     ************************************************************************
     ** Use the 'shu' command to correctly position the fader before       **
     ** doing a fade/dissolve with a custom FRANGE configured.             **
     ************************************************************************

    EXAMPLE USE
        By wedging the fader positions, you can find at what points light
        becomes exposed on the film. You can then set the FRANGE parameters
        to the low and high values that you find from wedging. You can then
        make two small scripts that turn the special fade/dissolve setup
        on and off. Make the following two files:

            *********************
            ***  0-170.RUN    ***
            *********************
            @#  ENABLE NORMAL FADES AND DISSOLVES (0-170)
            @! echo frange 0 170 >  foo.defs ! ldefs foo.defs
            @! echo FADES/DISSOLVES  NOW RUN FROM 0 TO 170 DEGREES
    
            **********************
            ***  90-150.RUN    ***
            **********************
            @#  ENABLE SPECIAL FADES/DXS (90=closed, 150=open)
            @! echo frange 90 150 >  foo.defs ! ldefs  foo.defs
            @! echo FADES/DISSOLVES  NOW RUN FROM 90 TO 150 DEGREES
    
    You then need only to run the appropriate script before shooting:

        run 90-150.run        # setup new fader values
        shu 90                # (fader starts in new position)
        fdi 12 rep 12         # shoot 12 frame fadein using 90-150
        rep 200               # (fader is at 150 for rest of shoot)
        dxo 24 rep 12         # dissolve out from 150 to 90 degrees
        cls cam 120           # (closes fader to 0 for windoff)
        run 0-170.run         # Go back to normal fades/dissolves

    BUGS
        none reported.

    SEE ALSO
        OPCS Commands
        CAM(OPCS)            - shoot camera (fades/dissolves too)
        OPN(OPCS), CLS(OPCS) - open/close fader shutter
        SHU(OPCS)            - move fader to an absolute position in degrees
        DXI(OPCS), DXO(OPCS) - set up dissolve in/out
        FDI(OPCS), FDO(OPCS) - set up fade in/out

        OPCSDEFS Commands
        FLOG(OPCSDEFS)   - set Fader LOGarithmic curve for custom fades
        FRANGE(OPCSDEFS) - set fade/dx's degrees range (for Hicon film stocks)
        INTERP(OPCSDEFS) - set interpolation positions (fader, focus, etc)
        SLOP(OPCSDEFS)   - correct for slop in a motor (fader, focus, etc)

        General
        MATH(DOCS)       - math expressions (for use in frame specifications)
        SYNTAX(DOCS)     - online calculator and OPCS math expression syntax

    ORIGIN
       Gregory Ercolano, Los Feliz California 04-21-92