It is very possible to do your own quick optical duplication of your Super 8mm films by using a synchronous refilming method. What is required is an ELMO GS-1200 Super 8mm projector which has the necessary synchronizing circuitry builtin, an accurate and sharp lensed Super 8mm movie camera (with the PC flash terminal and helpfully the macro lens feature), and a small synchronizing unit to connect the two together. Cresta Electronics in England make a small unit called a "GS - Interface" which is ideal for this purpose and other related sound synchronizing and post recording purposes. However....if you don't have one or are unable to get one...you can build my simple Synch Unit design yourself.

The actual duplication method can be as simple or as advanced as you'd like it to be. Using a front surface mirror and projecting the image on to thick ground glass or frosted glass or frosted plexiglass surface...to about 4 x 5 inches maximum, you will set up the camera and focus in tightly on this image. The camera will drive the Elmo GS-1200 projector via the Synch Unit and it will run frame per frame with the camera. If using a sound camera, you can also patch in the audio via the camera's AUX input socket, or using a low impedance patch cord into the MIC socket. Make sure you carefully line things up, and that you do a test to determine what exposure to use. Also.....remember to remove the builtin Daylight conversion filter if using color reversal film.

Once you have determined which exposure setting to use...it is best to lock the exposure manually. This will give you what is called a "one-lite print." If you need to correct density for some scenes.......determine ahead of time what exposure setting they should be refilmed at, and make detailed timing notes to yourself (with the projector's frame/footage counter as a helpful reference guide), and then just manually adjust the exposure to those required settings when you get to those scenes. To prevent incorrect exposure overlap......just stop the camera when you get to those scenes. Reverse the projector if necessary to bring it about 4 seconds before that scene begins, set up the camera's aperture for the correct exposure and begin the duplication. The 4 seconds ahead is wasted but is required to allow camera and projector to synchronize and stabilize in their synchronous lock. You will have to splice out these short bits later, however, using this stop and go method...you'll have exact scene density timing.

With using color correction filters over the camera lens for scenes requiring color correction....you can thus have accurate scene density and color timing as required. It will require you to make detailed notes, and run a film thru first to help you determine what you will or want to do. I also highly recommend a test film which will give you a good idea of how much correction you may actually need. When making your test film......combine light and dark scenes, and scenes with good color and poor color. This way, the test will become a master reference for you.

Synch Unit for the Elmo GS-1200 Super 8 Projector

The entire unit can be built on a small circuit board and installed into a small experimenter's project box. A hole drilled on both ends will allow a PC cable to exit on one end and an ELMO 5 pin DIN plug on a cord on the opposite end. All parts are available from Radio Shack or other similar electronics parts houses (Maplin etc). The LED indicator is optional, but I feel that it is worth having one to remind you when the unit is on, and or that there is sufficient power for a clear signal. The Synch Unit puts out a special pulse wave which is read by the Elmo built-in synch buffer and thus will slave the projector to the incoming signal.

PARTS LIST:

• PC cord with PC contact
• ELMO 5 pin DIN plug*
• Electrical cord for the Elmo 5 pin DIN plug
• 50 volt 1 amp Diode Rectifier
• .22uF 50 volt capacitor
• [R-1] 68k 1/4 watt Resister
• [R-2] 1.2k 1/2 watt Resister {for LED}
• Toggle Switch
• LED 9 volt or if 12 volt use Item #7 above to lower voltage
• 9 volt battery contact plug with wire harness
• small circuit board
• Small project box

ASSEMBLY INSTRUCTIONS:

• The two lower left pins on the Elmo plug as it faces away from you, are the only ones used. The far left pin is the Positive and the next one to it is the Negative, wire it accordingly.
• The Positive wire will run to the positive end of the 50v 1A Diode Rectifier, and continue on to the PC Plug Casing.
• The Negative wire will run to the .22uF 50 volt Capacitor at which same junction will be the negative end of the [R-1] 68k 1/4 watt Resistor. Solder this junction, then also solder the opposite ends of the diode with the opposite end of the resistor.
• Continuing on in the circuit from the end of the above resistor [R-1], wire it to the Negative wire terminal of the 9 Volt battery plug. At this same junction wire the negative side of the LED and to the other end of the LED wire in the [R-2] 1.2k 1/2 watt resistor.
• The end of the R-2 Resistor will be wired to the PC Plug Center Pin wire. To this same junction connect the Toggle Switch open end.
• To the other end of the Toggle Switch connect the Positive side of the 9 volt battery Plug harness.
• Drill out on a small project box, with a 1/8th inch hole on either end. On the project box Lid drill out a 1/4inch hole for the LED(or as required), and a hole as required for the toggle switch. If you need a mounting hole for the circuit board...drill a hole for that also.
• Assemble components into the project box in such a way as to allow a 9 volt battery to fit. You might want to glue a small piece(s) of foam to help allow the battery to keep from moving about.

TO USE THE SYNCH UNIT:
Hook the PC plug into your camera's PC terminal and the ELMO 5 pin DIN plug into the ELMO GS-1200 Projector's rear synch socket. Set the projector Synch Switch to the ESS position, set the same projection speed as your camera (e.g. 18fps or 24fps) will be running at, center the fine speed control knob, and also the Synch Control knob.
Now, assuming that you have already loaded up your film to be duped into the projector and set up either your mirror and ground glass setup or small screen to refilm from or other similar methods, you are ready to proceed. If you are transferring the sound from Track One (main track) to your duplicate, then use a patch cord from the projector's output to either AUX or MIC inputs on your Super 8mm 'sound' movie camera (using sound film of course for this procedure). HINT: Make a sound level test before actually filming, and adjust the camera's level control (or use ALC on either HI or LOW bias settings as required) to your own discretion.
Opearte your projector (assuming that the room is darkened to minimize any stray light or reflections, and all necessary tests and adjustments have already been made), and the projector should click on and stay in the Standby mode. Now, operate your camera (either manually or via a remote control {preferred method} or set the lock-run switch to continous run).......and the projector should immediately slave itself to the camera and run in synch. CHECK the Synch Meter Needle on the ELMO GS-1200 for centering and adjust it as necessary. [Make sure your camera has fresh batteries and that it is in good operating condition. Should it run too slow; you won't be able to maintain synchronous operation]. The projector usually rides synch within a few frames to get up to speed and then stays in synch throughout the duplication quite well. Even so....keep your attention to the operation of both camera and projector and observe the Synch Meter Needle and adjust synch as necessary.

NOTE: If you have any problems, check your synch unit power supply, your camera's batteries, check all connections, check also for a jammed cartridge etc. Provided you have constructed the unit properly, then the system should work fine. This unit can be used for various exciting techniques:

• Synchronized rear screen projection
• Duplicating your own films (with or without sound on Track one)
• Titles over a moving background [use clear acetate title sheets with transfer lettering...positioned over the image on the ground glass screen]
• Refilming a scope format film to flat format, and other effects
• Use your imagination for whatever other special effects you would like.

Happy Super 8mm Filmmaking!

Best wishes,
Martin
See Martin's WWW site at: Plattsburgh Photographic Services

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