Filmstrip projection
- a series of still pictures on a 35 mm of film
- often accompanied by a sound cassette programmed to automatically change filmstrip using a 50 Hz. signal to activate advance
- almost all programs come with a dual recording; automatic (inaudible 50 Hz. pulse) on one side, manual (audible pulse) on the other.
Formats
- single frame; most common, held vertically for projection, ½ of full frame
- double frame; produced on regular 35 mm camera using full frame and held horizontally for projection
Handling filmstrips
- handle filmstrip by edges to avoid fingerprints
- filmstrip is inserted upside down and backwards (when you are behind the projector, facing the screen)
Storage
- best stored in original container
- cabinets available
- some projectors use a cartridge
Advantages
- easily and compactly stored
- always in proper sequence
- can project silent strips at own rate
- must always be shown in the same sequence
- easily damaged in handling
- most designed for single-frame filmstrip; but some can handle both and others adapt for slides
- sound filmstrip projectors use a cassette tape as sound source. Inaudible pulse is used to synchronize.
- a 50 Hz. pulse is usually used, but some have 1000 Hz. pulse
- viewer/projector models available
Operating procedure
1. remove front screen units from case and plug in
2. insert filmstrip upside down as you ace the lens (strip should curl toward screen)
3. hold film along edges and push into slot until it can go no further
4. turn ADVANCE knob until film comes out exit slot
5. turn on projector and turn on lamp (the Dukane has two separate switches, both must be on for advance reverse to work)
6. advance to focus/start frame and focus (frame if necessary)
7. raise or lower base as necessary
8. for sound projection advance filmstrip to frame saying “start the tape here”
9. insert tape, rewind to beginning and push play
10. at end, turn lamp to frame
11. remove filmstrip, rewind by hand
12. when cool turn off, unplug, return to case
Cleaning
Dust off condenser lens with camel’s hair brush. Clean front and back of projection lens with lens tissue. Glass pressure plates need to be cleaned or dirt may scratch the filmstrip.
Troubleshooting
Problem | Cause | Solution |
Black screen | Lamp burned out. Cord not plugged in. | Replace lamp. |
First image two half-frames | Filmstrip not framed | Turn framer knob. |
Filmstrip not feeding properly | Filmstrip not correctly threaded | Remove and rethread. |
Filmstrip not engaged | Filmstrip not pushed in far enough | Push into slot until filmstrip can go no further. |
Spots on screen | Dirty projection lens. Dirty condenser lens. | Remove lens and clean. Clean with camel’s hair brush. |
Permanent line on screen | Condenser lens cracked | Replace lens/take in for repair |
Fuzz or hairs at edge of image | Dirt in aperture and film gate | Open gate, clean |
Framing is important. Images must be framed to be viewed clearly.
Motion picture film
Definition
A series of still photographs or drawings on film projected by means of light to give allusion of continued movement.
- Film widths – 8mm, 15mm, 35 mm, 70 mm
- Film parts – sprocket holes, picture frame, soundtrack
- Film speed
o sound, 24 frames per second, 36 ft. per minute
o silent, 16 frames per second, 24 ft. per minute
History
- First successful photography of motion by Edward Muybridge, 1878 pictures of running horses
- First public showings in Paris, 1895.
- First major movie ‘Great Train Robbery’, 1903
- First major talkie, using phonograph timed to film, ‘The Jazz Singer’, 1927
- ‘Sound era’ dated 1929 when thousands of cinemas were equipped for sound
- Cinema Scope a wide-screen process first used in the 1953 film ‘The Robe’. Uses an ANAMORPHIC lens which squeezes a wide picture onto a standard 35 mm frame
- 3D films became popular in Hollywood in 1953. This system required Polaroid glasses. Dial M for Murder, Kiss Me Kate and House of Wax considered to be the best films produced using 3D.
- IMAX a large screen format developed in Canada and introduced in 1970 at the World’s Fair in Osaka, Japan. First commercial IMAX theatre opened 1987 in Winnipeg.
The motion picture film projector
16mm projectors
Types
- manual load
- automatic load
- slot load
The slot load is the easiest to load, and also rewinds easy.
- Film comes off a feed reel in a clockwise direction and goes onto a take-up reel.
- The film coming off the feed reel has an image that is upside down and backwards.
Prepare your room
Locate power source. Carefully position screen, projector and speaker. The speaker should be located close to the screen, 4’ – 5’ from the floor and directed towards the audience. Cords should be kept away from the aisles and secured at each end. Blackout must not impede ventilation. Test film and equipment prior to presentation.
Film check
- Title on leader should be same as that on the can
- Holding reel upright with film leading away from the top to the right, sprocket holes should be on nearest edge of film to you – otherwise rewind
- Look for any indication of film breakage
- In winter, if film has been subjected to the cold, expose at room temperature for at least 15 minutes prior to showing.
Equipment check
- Assemble, see all switches are down and plug in speaker and power cords
- Clean lenses with lens tissues and gate with brush
- Switch on light. Check lamp, raise and centre light beam on screen, focus edges. Switch off light. Wait for lamp to cool before switching off motor.
- Clean apertures again in back and pressure plates if necessary.
- Switch on amplifier and wait for a few seconds for exciter lamp to light up. Turn up volume to check connection from projector to speaker. Turn back volume control.
Thread film and check manually.
Presentation
Run the show correctly. Arrange to have someone switch off room lights at your signal. Switch on amplifier. Watch for figures 11, 10, 9 … 3 to pass aperture, switch on light, focus and turn up volume simultaneously. Adjust tone and volume as necessary.
At end of film partner should be ready to switch on room lights. Turn projector light off and sound volume right down. Wait until film has run through machine. Remove full take-up reel but leave motor running until lamp is cool. Exchange reels on feed (forward) and take-up arms and rewind.
Care of films and equipment
The projectionist has a great deal to do with prolonging the life of the film. Most damage that occurs to film is due to careless handling and improper threading.
Film damage can be avoided if the following practices are followed:
- Keep the projector clean in good repair.
- Thread the film through the projector carefully.
- Occasionally check film for damage as it goes on take-up reel.
- Avoid the use of bent reels.
- Inspect the film while rewinding.
- Store film in cool place when not in use. Note: Extreme heat and cold are injurious to film. Expose very cold films to room temperature for a time before showing. Do not place near a hot radiator or stove or carry films in the trunk of a car.
- Keep film off the floor.
- Never cinch film on reel.
- NEVER LEAVE THE PROJECTOR WHILE IT IS RUNNING.
Safety precautions:
- Disconnect the power cord when checking fuses or changing lamps.
- NEVER LEAVE THE PROJECTOR WHILE IT IS RUNNING.
- Do not use worn or frayed power cords.
- Secure projector and speaker so that there is no danger of them being knocked over.
- Keep the speaker and power cords out of aisles whenever possible.
- Do not clean projector gate or sprockets while machine is running.
- If a film breaks while running:
o switch off the lamp
o stop the machine - Do not use tape to join the broken ends. Re-thread the film leaving sufficient to wind around the take-up reel. Mark the position of the film break by inserting small piece of paper. Leave note showing in the film can that the film is damaged.
Troubleshooting a 16mm projector
Problem | Cause | Solution |
No sound | Exciter lamp burned out. Projector is on silent speed. Projector is set for magnetic sound. | Replace bulb. Turn to sound speed. Turn to optical sound. |
Inadequate volume | Lint or dust on sound track. | Have film cleaned. Replace lamp. Turn up volume control. |
Fluttery movement on film | Lost film loop | Stop projector; readjust lower and upper loops |
Sound fluttery | Improper film loops. Film not tight over sound drum. | Stop projector; readjust lower and upper loops. Stop projector and tighten film on drum |
Dim pictures | Room is too bright | Relocate screen; place against windows or in the corner of the room |
Parts of two pictures on screen | Improper framing | Adjust framing device on projector. |
Lamp is burned out. Lens cover is closed. Power cord not plugged in. | Replace bulb. Open lens cover. Plug in cord. |
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