MP Research: Sodium Screen Vapor Process

Animation mixed with Live Action 

As part of my research, I will be looking into films that use 2D animation that mixes with live action and then continue to look at how that has developed into modern day movies with 3D animation and live action. In this post, I will be focusing on Sodium Screen Vapor Process.

Bedknobs and Broomsticks & Mary Poppins

This film was produced by Walt Disney Productions in 1971. It is filled with special effects particularly a technique that is known as 'Sodium Screen Vapor Process'. This technique can occasionally also be referred to as 'Yellow Screening'

http://www.fanpop.com/clubs/bedknobs-and-broomsticks/images/32846157/title/bedknobs-broomsticks-photo

http://www.fanpop.com/clubs/bedknobs-and-broomsticks/images/32846157/title/bedknobs-broomsticks-photo

This technique was used to combine actors, in real life enviroments, to background footage. In this case, it was in a fantasy, cartoon world like in the image below:

http://moviemezzanine.com/bedknobs-and-broomsticks-blu-ray-review/

Sodium Screen Vapour Procress

Filmmaker IQ quote 

'The Sodium vapor process used actors, who were lit normally, standing in front of a white screen which was lit by powerful sodium vapor lights'

 This particular process was done a lot in Hollywood in the 60s and 70s by Disney. Mary Poppins is another example. The process is done using an old three strip technicolor camera and a special prism.

http://filmmakeriq.com/lessons/hollywoods-history-of-faking-it-the-evolution-of-greenscreen-compositing/

Whilst shooting on a yellow screen, a wavelength of sodium vapor (yellow) would split off and make the background white whilst the other wavelengths split off and took the image of the lit actor. This left a black silhouette on the white background, known as a black and white matte. This then left the lit actor without a background so that filmmakers could add to it.

Yellow screening was just a step away from developing into modern day technology, green screening.