Why were the early movies in black and white, what was so difficult with colours? And what are the dots on old movies?


Why were the early movies in black and white, what was so difficult with colours? And what are the dots on old movies?

In: Technology

Movies are film. Film is a thin layer of light sensitive silver crystals. When light falls on the film, through the lens, the silver changes it’s crystal structure. When the film is “developed” the changed silver is washed away. These crystals are very, very tiny leaving collections and clumps of very tiny black pigments.

The reason it’s B/W is that the crystals react the same regardless of the color of light that contacts them.

Making color film involved making three layers (OK, it started with two but I’m describing Technicolor) of filters and three layers of film which were exposed at the same time; developed separately; and used to transfer colored dye to the film strip that was projected in the theater. It was an astonishing effect when audiences first saw color in the theater.

The earliest film cameras were black and white. They used a light sensitive substance (which is called photographic emulsion.) Basically, you open a lens to focus light onto a piece of film. The film reacts to the light. Areas that were very bright will end up white, areas that were very dark will end up black. It preserves brightness, but not colour.

The earliest video cameras worked on the same principle – they just had a moving reel so you were capturing 20-30 images per second, and then you could project those images by shining light through them.

The problem with capturing colour is that you need to filter the light somehow. All your film does is react to light. So the early colour video cameras actually used multiple lenses with filters on them – Technicolor originally used two film strips, one with a red filter and one with a green filter. The red one would capture the intensity of red lights, the green one would capture the intensity of green lights. When you projected it, you’d have to project the two film strips at the same time, and you’d have to project them through filters, and line them up so that the images overlap and play simultaneously. In short, it was a lot of work and required special equipment, so that’s why it didn’t really catch on.

After that process was invented, another process was invented where they would film on three different strips with three different cameras, and they could print the three strips together onto one strip with special coloured film, so that it could be projected with ordinary light and didn’t require a special projector. That’s called three-strip Technicolor, and it was the dominant way to film and project movies in colour for about 40 years.

A movie is in essence a long series of photographs. A photograph is simply a piece of parchment that is stained by the activity of light. The parchment reacts with light, and the light causes the parchment to develop a colour: Lots of light creates a light colour on the parchment, not very much light creates a dark colour. old-timey photography can’t capture the wavelength of light (which is what determines colour), it can only record whether or not light was present, and how much of it there was.

Colour photographs required the invention of light-sensitive chemicals that were sensitive only to a specific band of colour, rather than to all visible light. The early days of colour photography did this using three different chemicals, which were held on three different pieces of parchment, effectively meaning that you have to take the same photograph three times. Obviously, this is quite inconvenient when you need to make a movie. Colour film was technically possible long before colour movies started to be made, but it wasn’t until Kodak managed to put all three colour-sensitive chemicals onto a single parchment at the same time that you could really make these movies worth your time, and it took another 10 years after that before the technology got good enough for people to properly bother making colour films.

The dots you asked about are dust or scratches on the film. Dust would show black on the screen, deep scratches would show white.

The circle near the upper-right-hand corner about halfway through the film was a cue for the person showing the film to start the projector with the next reel so the film could be enjoyed as a seamless whole instead of having to take time to stop the projector, load the next reel, and then resume the film.