My current work-in-progress – a novel set in Hollywood in the 1920s and 1930s – regularly sends me down all kinds of research rabbit-holes. Much as I’m writing fiction, I want to get as many of the facts straight as possible.
My latest quest was driven by a simple question: in a small studio screening room of the period, what material would the projection screen have been made from? Easy enough to find the answer, you might think. Just ask Google, right?
Wrong. As so often happens, a basic internet search yielded nothing of any use. So I swiftly turned my attention to a more specific online resource – one I’ve used many times before. It’s the Media History Digital Library, a free repository “featuring millions of pages of books and magazine from the histories of film, broadcasting and recorded sound.” If you have any interest in the history of cinema, you won’t find a shinier treasure trove than this.
Past experience of using the site steered me immediately to the annals of the New York-based Society of Motion Picture Engineers. Founded in 1916, The Society brought together technical experts from the fields of research and engineering, plus motion picture manufacturing and production executives. Every year it held two conventions, each lasting around four days, where a wide range of papers was presented and discussed, and new equipment demonstrated.
Luckily for curious folk like me, full records of these conventions are available as searchable documents at the Media History Digital Library, under the title Transactions of the Society of Motion Picture Engineers. Here’s what I discovered.
At the meeting of October 8-9, 1917, R. P. Burrows gave an address entitled Light Intensities for Motion Picture Projection, presented in the journal by J. T. Cardwell. Burrows identified two classes of projection screen then in common usage: diffuse reflecting screens and spread reflecting screens:
Of the first class, white cloth screens and plaster screens are typical. A white cloth screen when clean can be made to reflect as high as 70 to 75% of the light which strikes it; and a plaster screen 80 to 88% … Such screens are well adapted to theatres in which the position of the seats with respect to the screen is such that the picture must be viewed at relatively large angles.
Aluminized screens and ground-mirror screens are examples of the spread reflecting class. A clean aluminized screen can be designed to reflect about 60 to 65% of the light striking it and will confine the reflect light within an angle of approximately 30°. Ground-mirror screens when clean can be made to reflect approximately 80 to 90% of the light … Such screens are well adapted to theatres in which the seats are so arranged that the picture does not have to be viewed at large angles.
This extract alone told me pretty much everything I needed to know – in the early days of cinema, your basic projection screen was probably just a smooth plaster wall or a hanging piece of stretched muslin. However, 1916 was a little early for my requirements and, anyway, you know what rabbit holes are like – just ask Alice.
Fast-forwarding ten years to 1926, I found this report from the Society’s Progress Committee rounding up some of the latest advances in screen technology, culled from such publications as Photographische Weekly and Kinematographic Weekly:
An unusual motion picture screen described in a German publication consists of a surface composed of colored strips continuously moved by two cylinders. Pictures projected on to this screen are said to be more intense in daylight than pictures projected on an ordinary screen in a darkened room. An artificial cloud or mist produced by a spray has been used as a projection screen for the projection of motion pictures in a Berlin park. Another screen developed by an English inventor is made of mottled opal glass. It is built in sections which fit together, leaving the cracks invisible to the observer. The screen is permanent and washable.
All very interesting, but far too experimental for my tastes. Setting the report aside, I delved into the individual conference presentations from October 1926 and came up with this note about another report, this time from Moving Picture World magazine:
If a surface of magnesium carbonate prepared in the laboratory is taken as one hundred per cent white, then the reflecting power of plaster, cloth and beaded surfaces are about 80, 60 and 78 per cent, respectively. The specially prepared specular screens which concentrate the reflected light along the axis may show a value of perhaps four hundred per cent when viewed normally.
So there you go. A decade on from 1916 and you’re still looking at two basic choices for your projection screen: good old cloth or plaster or, if you really wanted to push the boat out, you could indulge in a fancy specular affair of the type that spawned the phrase “silver screen.” I judged that, for the purposes of the scene I was working on – which takes place in an informal screening room and not a public theatre – a plain white wall would do just fine. Decision made, I drew a line under this particular foray into the roots of cinema, and returned from fact to fiction.
Just before ending my session at the Media History Digital Library, I downloaded the table shown below. It formed part of an address given in 1926 by Loyd A. Jones and Clifton Tuttle, entitled Reflection Characteristics of Projection Screens:
Tuttle worked at Eastman Kodak’s research laboratory, and the presentation brought together data he’d gathered with his colleague Milton F. Fillius, based on tests conducted on forty different projection screens from various manufacturers. I won’t go into the results here – they’re extensive and highly technical – but if nothing else the dizzying extent of their list proves one thing: there sure were one heck of a lot of companies competing to convince theatre owners that their particular product – whatever it was made from – was the best darn projection screen in Hollywood.