Video

Around 1936.

sound on film is achieved by sacrificing a little portion on the side of the film frame to fit a sound track (this is also probably where the term "soundtrack" came from) early 35mm films use an optical sound method. on the projector's sound reading area, there's a light bulb (usually called the exciter bulb) that shines light into a little slit. that slit only lets a small ribbon of light to pass through into a photoreceptor/light detecting cell. the sound track is basically going to let a specific amount of light to hit the light detecting cell by blocking the ribbon of light with dark areas. the size of dark areas vary with the volume and frequency of the sound intended to be reproduced, lower volumes have more dark areas and louder volumes have less dark areas. the dark areas also vary much more minutely to produce the specific frequency intended to be reproduced. higher frequencies have the areas vary more frequently and lower frequencies are less frequent. the light that's received by the light sensitive cell is converted into electrical currents, then these currents are greatly amplified and the amplified signal is then fed into the speaker, which reproduces the sound.

You know anybody that teaches people to run 35mm?

Well said, I would like to represent this feeling as you look to a paper or vinyl artificial flower rather than a real garden one with all its swings, feels and aroma. Although i understand that a person grown up in digital age will hardly appreciate the old school 35 mm motion picture handling in Cinemas due to mindset difference "Analog vs Digital"

Actually, films run at 24 fps, while youtube videos run at an average of 30-60 fps.

The takeup reel is powered and the feed reel is unpowered, with a little bit of drag to keep mild tension on the film. Usually the upper or front spindle holds the feed reel and the lower or rear spindle holds the takeup reel. If you have a projector with both spindle arms on top, and you are facing the right side of the projector where the controls and threading path are, the left reel will be the takeup reel when going forward. If your projector can play in reverse, the feed and takeup reels will reverse roles. When you have played the whole reel of film and let the tail run out the back of the projector (or better, stopped it before the tail leader and unthreaded the projector) you take the end of the film flapping loose on the left (rear) takeup reel, and thread it counter-clockwise around the hub on the right feed reel, putting an inch or so of the film in the notch in the hub for that purpose. Then hold your fingers _lightly_ on the rim of the full reel to provide a little braking, and put the projector into rewind. Keep you hand on or near the reel until the whole reel is rewound. If the film starts getting loose between the reels, apply a little pressure to the rear reel to tighten up the film a bit. If you don't do this and let the film rewind by itself, about half way through the reel the film will get loose, then usually drop off one reel or the other, tangle in the spindle supports, and stretch and break the film. Then you will have to cut a couple of feed of damaged film out of the middle of the show and splice the ends together.