DXI(OPCS), DXO(OPCS) Optical Printer Control System DXI(OPCS), DXO(OPCS)
NAME
dxi/dxo - set up dissolve in/out
USAGE
dxi [-x] frames
dxo [-x] frames
EXAMPLES
dxi 12 # set up a 12 frame 'dissolve in'
dxi -x 12 # 12x fade, regardless of current fader position
OPTIONS
-x This allows dissolves to be setup even if the fader is not
fully open or fully closed. (Errors are disabled)
DESCRIPTION
Sets up a dissolve in or out, so that any commands involving exposing
camera film (cam, rep, etc), the fader will automatically move
to the proper positions for each frame.
1) Setup and shoot a 12x "dissolve in" on a held projector image:
dxi 12 cam 12
| |
| Shoot 12x dissolve in on frozen projector frame.
|
Set up 12x dx in
2) Setup and shoot 12x "dissolve in" as a straight print:
rat 1 1 dxi 12 rep 12
| | |
| | Shoot 12x dissolve in on moving projector image
| |
| Set up 12x dissolve in
|
Set up a straight print for the 'rep' command
3) Setup and shoot a 24x 'lap dissolve' between two moving projector
images. (Assumes 'rat 1 1' in effect for straight print):
dxo 24 rep 24 seek >5500 -24 dxi 24 rep 24
| | | | |
| | | | Shoot 24x dissove in
| | | | as straight print
| | | |
| | | Setup 24x dissolve in
| | |
| | Backwind camera -24x, projector seeks x5500
| |
| Shoot 24x dissolve out (straight print)
|
Set up 24x dissolve out
Commands can be 'all on one line' as shown above, or separate:
dxo 24 # Setup 24x dx out
rep 24 # Shoot 24x dx out as straight print
seek >5500 -24 # Backwind cam -24x, pro goes to frame #5500
dxi 24 # Setup 24x dx in
rep 24 # Shoot 24x dx in as straight print
Note: seek >5500 -24 is effectively the same as cam -24 pro >5500
though the latter may be slower to execute.
4) Set up and shoot (12) 4 frame lap dissolves between every 8th
projector image:
do 12 dxo 4 cam 4 seek -4 pro 8 dxi 4 cam 4
^These commands repeat 12 times from left to right.
..having the effect of 'weaving' still frames from an otherwise
slow-motion moving projector image.
NOTES
opn, cls, shu, dxi 0, dxo 0 will cancel any pending dissolves.
A status message near the fader's counter shows the remaining frames
left for an in-progress dissolve.
If the -x flag is NOT supplied, the fader:
o Must be fully OPEN before executing DXO (dissolve-out).
o Must be fully CLOSED before executing DXI (dissolve-in).
..otherwise an error will be printed. Below are common errors:
dxi 12 cam 11 dxo 12 cam 12
^bombs here: only 11x into a 12x DXI.
opn dxi 12 cam 12
^bombs here: fader is already open
It's hard to see such errors in large '.run' scripts, so it's
advised to test scripts with 'motors off' to find such problems
quickly, without wasting film or waiting for motor positioning.
DISSOLVE-SPECIFIC INSTALLATION NOTES
When setting up a new system, shoot extensive cross-dissolve tests
to make sure the INTERP(OPCSDEFS) values for your fader are correct.
If interp values aren't accurate, or there's mechanical slop in the
shutter (see SLOP(OPCSDEFS)), you will see bumps in exposure. Test
with different length lap-dissolves, and project on a large screen.
Fine tuning SLOP and INTERP are essential for accurate dissolves.
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 11/29/89