Harryhausen and Sodium lamps

[George Ebersole]

So, I'm listening to the commentary on various Harryhausen blurays in my library, and he and others keep mentioning that the studios in the UK used sodium (Na?) based lamps for effects work. And that this somehow gave a better composite image or reduced the matte lines or something. It wasn't really clear how the sodium lamps helped.

 

Does someone know? Is there something about the way light uses Na to cut a closer matte line or something?

[Samuel Berger]

Are sodium lamps cooler than the alternatives of the time? Because the one thing that comes to mind is how miniature sets would be affected by the heat of the lighting required for 1950s filmstocks....

[David Mullen ASC]

They aren't referring to sodium lighting used for sets or people but for chroma key screens using the sodium matte system created by Petro Vlahos:

 

https://en.wikipedia.org/wiki/Petro_Vlahos

 

The Wikipedia article is wrong though -- "Ben-Hur" used blue screens and the new color difference matting system, not sodium screens. See:

 

https://en.wikipedia.org/wiki/Sodium_vapor_process

http://nzpetesmatteshot.blogspot.com/2010/07/mary-poppins-supercalifragulous-visual.html

 

The system involved using a converted 3-strip Technicolor camera to simultaneously record the beauty pass and the matte pass at the same time. Since the color negative stock used for the foreground element was not very sensitive to sodium light, there was little problem with spill on the actors from the screen lit by sodium light.

 

There was only one camera ever made to do this process and it was almost exclusively used by Disney. Resurrected by Harrison Ellenshaw on "Dick Tracy" for a shot in an opera house that was lit blue by Storaro, so a blue screen couldn't be used.

[George Ebersole]

The system involved using a converted 3-strip Technicolor camera to simultaneously record the beauty pass and the matte pass at the same time. Since the color negative stock used for the foreground element was not very sensitive to sodium light, there was little problem with spill on the actors from the screen lit by sodium light.

Very cool response. Growing up watching those films I was always impressed the way the images were composited together, and how they seemed to avoid matte lines and that white splatter when the composite was a bit off.

 

Amazing. Thanks very much for the reply, and I didn't check Wiki first because there's always some error in the articles somewhere.

 

Many thanks, again.

[Tim Smyth]

They aren't referring to sodium lighting used for sets or people but for chroma key screens using the sodium matte system created by Petro Vlahos:

 

 

There was only one camera ever made to do this process and it was almost exclusively used by Disney. Resurrected by Harrison Ellenshaw on "Dick Tracy" for a shot in an opera house that was lit blue by Storaro, so a blue screen couldn't be used.

Thanks David,

Always a lot of confusion with these processes. And yes, Ben Hur used blue screen process, I think developed by the same guy you mentioned, since maybe they were shooting widescreen, and the other cameras could not handle that.

 

There must have been two cameras made, since one was in England, and did the traveling mattes for several Harryhausen pictures. I think the prisms were different though, the Disney one cheaped out a bit. The Disney camera was also used for at least one shot in The Black Hole, where the characters are running across a bridge, when a miniature asteroid is rolling towards them.

 

It is a bit regretful that all these processes are now extinct due to the advancement of the computer. Of course a bit of irony there, since we are all communicating to each other using computers.

[Darrell Ayer]

I learned about Sodium process from it's use in Mary Poppins. It's a brilliant solution to Matting and Disney should have used it more since they kept it to themselves.

 

I love the inventiveness of optical techniques.

[Jay Young]

 

There must have been two cameras made, since one was in England, and did the traveling mattes for several Harryhausen pictures. I think the prisms were different though, the Disney one cheaped out a bit. The Disney camera was also used for at least one shot in The Black Hole, where the characters are running across a bridge, when a miniature asteroid is rolling towards them.

 

 

I have always wanted to know how that was done!

[Christopher Vaughan]

If you are interested in the development of the sodium vapor process and its evolution into green screen. it's covered very well here https://www.fxphd.com/details/402/

[Mark Dunn]

If you are interested in the development of the sodium vapor process and its evolution into green screen. it's covered very well here https://www.fxphd.com/details/402/

You're aware this is a subscription site, don't you? It doesn't tell you anything unless you pay.

Edited November 28, 2018 by Mark Dunn

[Christopher Vaughan]

You're aware this is a subscription site, don't you? It doesn't tell you anything unless you pay.

 

I am. The VES Handbook is also about $100 if you would like a cheaper option.

 

https://www.amazon.com/VES-Handbook-Visual-Effects-Procedures/dp/B01FKS8W56/ref=mt_paperback?_encoding=UTF8&me=&qid=

Edited November 28, 2018 by Christopher Vaughan