This guide lists out formulas to achieve common effects using a JK Optical Printer as well as detailed descriptions of what each key does. For each sequence, input the keys in the order that they appear. If there is a process that is not present and you're curious about what sequence to put in, email firstname.lastname@example.org.
PGM/PROG: program. Initiates the sequence and tells the computer that you're now inputting instructions as to what you want it to do.
NOTE: You will press this at the beginning and end of each command. A light will indicate if program mode is active or not.
CAM INDIV: moves the camera a single frame in either direction depending on switch setting.
PROJ INDIV: moves the projector a single frame in either direction depending on switch setting.
CAP SHTR: moves camera shutter to open or closed (advances camera one frame when cycled twice). A light will come on when the shutter is open to indicate its position.
PROJ TOTAL: displays how many frames projector has moved total. Adds to total when moving forward, subtracts when in reverse.
CAM TOTAL: displays how many frames the camera has moved total. Adds to total when moving forward, subtracts when in reverse.
VERIFY: press prior to any function key to check its value (i.e. VERIFY –> ALT COUNT to determine what value ALT COUNT is set to).
RUN: executes whatever has been programmed (i.e. runs camera and projector).
PAUSE: pauses whatever program is currently running. Press again to resume.
STOP: stops the program entirely.
Number Keys: use to enter values for each function.
CLR: clears value from last input (can be used to correct mistakes or double presses).
DECIMAL POINT: only used with exposure and delay time.
ENTER: completes entry of values for each function (i.e. set the value of a specific function and press ENTER to tell the computer you're finished entering said value).
PROJ PRESET COUNT: sets the total number of frames that the projector will move in the sequence.
CAM PRESET COUNT: sets the total number of frames that the camera will move in the sequence.
NOTE: the printer will not run if no preset value is entered. If only one preset value is entered, the sequence will end after that value is reached (i.e. if you only select CAM PRESET COUNT when you're entering your sequence, the sequence will stop when the camera cycles however many frames you've entered and vice versa).
PROJ ALTERNATE COUNT: number of frames the projector will move between camera cycles.
CAM ALTERNATE COUNT: number of frames the camera will move between projector cycles,
PROJ CYCLE/STEP COUNT: sets how many frames the camera and projector will alternate in a "STEP" sequence before the projector stops and the camera photographs a single frame.
CAM CYCLE/STEP COUNT: number of times the camera will photograph the single frame in a "STEP" sequence.
CAMERA SKIP COUNT: the number of times the camera and projector will alternate in a "SKIP" sequence before the camera stops and allows the projector to move independently.
PROJ SKIP COUNT: the number of times the projector will run independently of the camera in a "SKIP" sequence.
EXP TIME: changes the exposure time of the camera (measured in seconds). Use the DECIMAL POINT key to enter more precise values.
Basic Formulas to Get You Started
Please see the above section on terminology for a rundown of what each specific key does.
Freeze frames are perhaps the most basic function for an Optical Printer. The camera will essentially photograph an individual frame on the projector for however many frames it is told to. To achieve a freeze frame effect, locate your desired frame on the projector, then input the following sequence:
PGM -> CAM PRESET COUNT -> [however many frames you would like the camera to run] -> ENTER CAM ALT COUNT -> [however many frames you would like the camera to run] -> ENTER -> PROJ ALT COUNT -> 1 (one) -> ENTER -> PGM -> RUN
The camera will run continuously until the preset value is reached.
1:1 Direct Rephotographing
This sequence will allow the camera to rephotograph whatever is on the projector at the same frame rate in order to made an exact copy of the footage. Input the following:
PGM -> PROJ PRESET COUNT -> [number of frames that you would like to rephotograph] -> ENTER -> CAM ALT COUNT -> 1 (one) -> ENTER -> PROJ ALT COUNT -> 1 (one) -> ENTER -> PGM -> RUN
Fades can be done by running a 1:1 sequence and slightly closing the aperture down each frame. This can be done either manually or automatically using a frame count that corresponds with the desired length of the fade.
To reverse the projector, flip the corresponding switch to the down position and run for your desired frame count.
PGM -> PROJ PRESET COUNT -> [however many frames you'd like the projector to run] -> ENTER -> RUN
Return switch to the up position when finished.
Close eyepiece and shutter prior to starting! Flip the corresponding switch to the down position and run the camera for however many frames you'd like using a freeze frame sequence. Be sure to switch it back to forward when finished.
Slow Motion (Step Printing)
The process of slowing down your footage is dependent on the ratio of camera cycles to projector cycles. A basic 1:1 alternation will result in an exact duplicate of the original footage, however setting the camera alternate count to 2 and the project alternate count to 1 (a 2:1 ratio) will slow down the footage to 50%.
PGM -> PROJ PRESET COUNT -> [number of frames in the scene] -> ENTER -> PROJ ALT COUNT -> 1 (one) -> ENTER -> CAM ALT COUNT -> [number of frames based on ratio you're going for] -> ENTER -> PGM -> RUN
Transposing 18fps to 24fps (Cycle Print)
This sequence can convert super or regular 8mm, originally photographed at 18 frames per second, to 24 frames per second on 16mm film. To achieve this, input the following commands:
PGM -> PROJ PRESET COUNT -> 18 (eighteen) -> ENTER -> PROJ CYCLE COUNT -> 3 (three) -> ENTER -> CAM STEP COUNT -> 2 (two) -> ENTER -> PGM -> RUN
Fast Motion (Skip Printing)
The original footage runs through the projector at a ratio that corresponds with the number of frames the camera will move to the number of frames the projector will move, therefore omitting frames and speeding up the footage upon recapturing. To achieve this effect, input the following sequence:
PGM -> PROJ PRESET COUNT -> [total number of frames in the scene you're printing] -> ENTER -> PROJ ALT COUNT -> [number of frames that you'd the projector to skip] -> ENTER -> CAM ALT COUNT -> 1 (one) -> ENTER -> PGM -> RUN
For more advanced workflows like bi-packing or creating traveling mattes, email email@example.com.