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Re-creating Disney's sodium vapor process [video]

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Re: Re-creating Disney's sodium vapor process [video]

#3
Very interesting stuff.

I'm curious if this means anything in terms of good vs perfect technology or what tech wins out in practice. This process seems just plain better than green-screen, so why did it lose out? Is is just that green screen is good enough? Was it too hard to do this sodium vapor process with random cameras back in the day? Are sodium vapor lights bad enough in some way that practically it lost out?

Re: Re-creating Disney's sodium vapor process [video]

#4
post #3

Very interesting stuff. I'm curious if this means anything in terms of good vs perfect technology or what tech wins out in practice. This process seems just plain better than green-screen, so why did it lose out? Is is just that green screen is good enough? Was it too hard to do this sodium vapor process with random cameras back in the day? Are sodium vapor lights bad enough in some way that practically it lost out?

It lost because there were only 3 prisms made. It also required a lot more lot as running thru an optical splitter means at least half of your light was lost, it's not a big issue today. Modern cameras are insanely more sensitive than film was at the time. Alfred Hitchcock used this on "The Birds". In the YouTube video they got a great result even with a smaller studio than would have been used on Mary Poppins. The trick needed the screen as far back as you could get it to minimize the chance of spill, that used to be normal on blue screen before the software improved.

Re: Re-creating Disney's sodium vapor process [video]

#5
post #4
post #3

Very interesting stuff. I'm curious if this means anything in terms of good vs perfect technology or what tech wins out in practice. This process seems just plain better than green-screen, so why did it lose out? Is is just that green screen is good enough? Was it too hard to do this sodium vapor process with random cameras back in the day? Are sodium vapor lights bad enough in some way that practically it lost out?

It lost because there were only 3 prisms made. It also required a lot more lot as running thru an optical splitter means at least half of your light was lost, it's not a big issue today. Modern cameras are insanely more sensitive than film was at the time. Alfred Hitchcock used this on "The Birds". In the YouTube video they got a great result even with a smaller studio than would have been used on Mary Poppins. The t…

> It lost because there were only 3 prisms made.

But it seems so much better that that shouldn't have been a blocker. Like optics isn't magic, and knowing that someone did it before should be enough incentive? Not like movies are a small or poor industry.

Re: Re-creating Disney's sodium vapor process [video]

#6
post #3

Very interesting stuff. I'm curious if this means anything in terms of good vs perfect technology or what tech wins out in practice. This process seems just plain better than green-screen, so why did it lose out? Is is just that green screen is good enough? Was it too hard to do this sodium vapor process with random cameras back in the day? Are sodium vapor lights bad enough in some way that practically it lost out?

Practically, you could see it in the video: they had to have near-perfect lighting to avoid any 589nm spill on the subject, or they would end up with semi-transparent regions on the matte where they didn't want any. Chroma-keying is more tolerant to spill, only needs one camera with one film reel, and you don't need a special screen with special lamps and special cameras.

Re: Re-creating Disney's sodium vapor process [video]

#7
post #5
post #4

Earlier quoted context omitted.

It lost because there were only 3 prisms made. It also required a lot more lot as running thru an optical splitter means at least half of your light was lost, it's not a big issue today. Modern cameras are insanely more sensitive than film was at the time. Alfred Hitchcock used this on "The Birds". In the YouTube video they got a great result even with a smaller studio than would have been used on Mary Poppins. The t…

> It lost because there were only 3 prisms made. But it seems so much better that that shouldn't have been a blocker. Like optics isn't magic, and knowing that someone did it before should be enough incentive? Not like movies are a small or poor industry.

I wonder if it’s just more cost effective to use a well-established tool like green screen, and then contract out all the rotoscoping clean-up to other countries for less than minimum wage?

Re: Re-creating Disney's sodium vapor process [video]

#8
post #3

Very interesting stuff. I'm curious if this means anything in terms of good vs perfect technology or what tech wins out in practice. This process seems just plain better than green-screen, so why did it lose out? Is is just that green screen is good enough? Was it too hard to do this sodium vapor process with random cameras back in the day? Are sodium vapor lights bad enough in some way that practically it lost out?

Practically, you could see it in the video: they had to have near-perfect lighting to avoid any 589nm spill on the subject, or they would end up with semi-transparent regions on the matte where they didn't want any. Chroma-keying is more tolerant to spill, only needs one camera with one film reel, and you don't need a special screen with special lamps and special cameras.

> Chroma-keying is more tolerant to spill, only needs one camera with one film reel, and you don't need a special screen with special lamps and special cameras.

Fair on the number of films/cameras.

Is normal keying actually more tolerant to spill or is it just worse so you're going to have to manually deal with spill anyway so you just live with it? I don't even have good eyes and even I sometimes see spill in actual movies, or especially in TV. Edit: I guess that's _different_ spill though.

I mean you do famously need a special screen :) And you don't need _special_ lamps per se but you do have to light your greenscreen fairly well to have real success.

Re: Re-creating Disney's sodium vapor process [video]

#9
Very very cool, mindblowing actually, seems legitimately useful.

There have been a few art installations over the years that use these lights:

https://www.youtube.com/watch?v=hd077pa-5CI

For a second I thought that the video was from this channel, which also does experimental cinematography stuff:

https://www.youtube.com/watch?v=-4uzyhbDFas

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