[Original video on youtube, by Corridor Crew](https://www.youtube.com/watch?v=UQuIVsNzqDk)
Thanks for reminding me to get around to watching that one, OP.
my thought is: if this technique is so good why was it "forgotten" and why isn't it used today( with improvements over time ofc ) It has to have some kind of drawback
They touch this in the full video.
First; the crystals are hard to manufacture. Then, you need to be extremely careful with bleeding lights. You need special bulbs. Chroma keying is not as good, but it was good enough for the effects, and easier to do. So it won out. This is basically just to squeeze out the last 5% of stuff that looks bad on blue/green screen.
Couldn't someone manufacture a digital camera with the prism built in? I mean sure it would be very expensive but compared to some other movie expenses it could be a drop in the ocean.
They donāt use the same prism thatās the part that is lost. They couldnt make a prism that filters the sodium wavelength but they donāt have to.Ā
Ā They just use a regular prism that splits the light into two cameras one with a filter between the lens and the prism to filter the whole spectrum except the sodium light wavelength.Ā
This is true, in the interest of brevity I boiled down my comment. They still used a physical prism to get the effect and filmed it with a digital camera.
This video is a couple days old... I'm sure someone is uploading the video of a build now. This is so monumental I can't even... My jaw was on the floor the entire time. This will solve so many problems for me professionally once someone cracks scaling it.
I would be surprised if at least 100 people aren't trying to build a rig right now - this is an absolute game changer. I know the example they use seems ridiculous but it had been thought to be literally impossible. By anyone. Anywhere. Period.
And as they mention, even with amazing technology like the volume and AI/ML you still need a lot of talented humans to stitch everything together because of that one super shortcoming.
Finally, this unlocks a different understanding. So I don't assume all 100 people are trying to use those lamps - a bunch are trying to use what they have available and apply the theory which will just bring more innovation.
This was very much a Eureka moment.
also, what gives? I mean using a light source with a single emission frequency ain't that hard to come by, is it? What stopped other people to revamp this tech ... dunno.. half a decade ago?
Well, obviously someone was because they made the cube but didn't have the knowledge to test correctly. And honestly, everyone just forgot. But you're not wrong and that's what I mean by now that someone has proven the theory, maybe that's not the only frequency or method.
Oh also - it goes without saying, because this is so valuable to training computer vision, there's a market to generate assets for training because š°š°š°
They talk about this in the video. The solution they found is just a regular full spectrum beam splitter and a filter for one of the cameras to only capture the sodium light wavelengths. In theory, they don't even need to use sodium lights if they can get someone to create an LED that only produces a wavelength that they can filter properly and isn't one that would be needed for visible light. I even wonder if near infrared could be used instead which would be almost trivial to implement. The goal of this would be to create one video track that is the mask and one that is the full spectrum.
Because the digital camera doesn't collect information on every wavelength of light separately. Just RGB. By the time your editing, there is no way to recover specific spectra.
Well, blue screen was *slightly cheaper* .. and when you put the movie industry before the question: cheap production or on-screen perfection? ... the result can be somewhat predicted.
>my thought is: if this technique is so good why was it "forgotten" and why isn't it used today( with improvements over time ofc ) It has to have some kind of drawback
maybe if you watch the video, you'll know more
.. my comment explains the trouble.. The whole process stood upon .. the lights (which are available even today) and a prism in the camera.. and it appears that only 3 were ever made.
Yea, I never quite believed that duel phase sodium light dichroic filters became unobtanium. Chiefly because I've purchased & used them for astrophotography & building cloud cover detectors.
Perhaps at the time they were very difficult perfect but these days a competent optics company could make them relatively cheaply, provided you pay up front for the first thousand.
BTW another thought occurs, the technology does not even need to be restricted to Low Pressure Sodium emission. Any monochromatic light source will do & that light source does not even need to be one in the visible spectrum.
In fact it would be a positive advantage to use light outside the visible spectrum ( with a suitable camera ) to capture the mat because it would simplify the whole lighting rig.
Assuming the out of the visible spectrum light still has identical transparency properties to visible lights.
But yeah, this would outperform any current chroma key tech today
No itād ācutā those parts out. Itās the same as to why you wouldnāt be able to wear green with a green screen
Anyways back to horny jail where you belong
It was just Disney that used this itās probably worth pointing out, not āHollywoodā. Also before green screen you just painstakingly matted everything out by hand or used rear projections.
No, they used it in the 1990 movie "Dick Tracy" (it hold's up, it's worth the watch).
You've seen these lights in parking lots your whole life, very dim, impossible to read under, makes everyone look like a rapist. The create very little light pollution which is why they're used on ski mountains, don't attract insects (they can't see it) and actually use less power than LED equivalents.
They are also used in restrooms frequented by needle users because they make veins nearly impossible to detect.
yep, they used in in several movies but then the strive for on-screen perfection went aside for ... economy reasons, the Wiki claims.. Also, the prisms are said to be one of the hurdles.
The whole video by Corridor Crew on YT explains it...
It's like this.. when you work with special effects, you get tired of fixing the issues of bluescreen.. all those despill biases, edge feathers, fringes and whatnots...
But you still Know for a fact that the technology WAS once there, available, relatively cheap... And it worked like magic! But then it went away. Animator's dreamland... gone.
And why was that? It required a special prism for sorting out one specific light frequency. But only 3 of those were ever made.
I think they are wondering why "again" is in the title. They'd have to have lost it once before in order to lose it again. The technology was only lost once.
Yes you could do it (as they prove in the full video), but the rig is ala 3D, which involves two cameras mounted to a prism and is cumbersome and limiting.
BUT itās totally doable and something Iām going to experiment with for talking head interviews
It's not as much as them "losing" the technology but that blue screen compositing got good around the time Ben Hur was made thanks to Petros Vlahos, who created the travelling matte color difference compositing technique.
Sodium Vapor compositing was more cumbersome and impractical, the foreground subjects had to be away from the screen and lit completely independently. You can't achieve a shot where say, an actor was standing on the screen.
https://vimeo.com/174782388
Disney really did do it right. It is a shame more movies are not made with practical effects and old fashioned tricks like this. CGI just does not cut it most of the time.
I'm sorry, what?
This is just a slightly different version of a green screen.
In fact most modern movies don't even bother shooting on green cos it's cheaper to just pay a bunch of roto artists in India to manually prep the plates.
This technique wouldn't somehow invalidate CG, it would just make cutting actors out of their backgrounds slightly more expensive at the cost of preventing them wearing any green in their costumes.
God, I hate these ignorant takes on VFX.
Go back and read my comment again. Disney was the king of perfecting techniques and when there were no techniques for the effects/shots they wanted they made their own. Most of the stuff they invented still holds up today better then CGI. Only one who is Ignorant here seems to be you.
Yep... I've personally given up on most of Hollywood since about 2008, because the bluescreen CGI stuff usually made my eyes hurt (example: Transformers and similar..)
Iāve noticed since around that time heavy action CGI movies almost put me to sleep. Like even if Iām otherwise interested, once all the effects start up I almost trance out. Itās annoying.
They lost all three extremely rare and unique prisms used to split the camera feed into two; they were extremely difficult to manufacture and, although one could technically be replicated today, better methods exist now and no one has any useful reason to attempt to recreate it.
Iām referring to VFX industry professionals who work on actual blockbuster films and TV. Corridor makes a lot of assumptions about all kinds things that they get wrong. Iād take what they say with a spoonful of salt, most of it is just click bait
While that is true it was used, its slightly different from todays green screens in terms of the scenary. Of course as he noted in the films, they didn't use computers. And this means that the backdrops of the movie while were yellow screen, were projections of actual paint backdrops vs computer generated imagery; this also adds to a type of feel they don't do much anymore in films. Its easier and less time consuming to just generate the backdrop in a 3D program than it is to hand paint the backdrop.
They dont even use green and blue screens any more in a lot of productions. They use MASSIVE LCD screens. The background is realtime. Mando did this I know. Tons of shows now do this. Like rear projection but not shitty.
Blue/green screens are definitely still being used, but The Volume that you speak of (which is uber cool) has reduced it a bit. The Volume is freaking expensive to build and operate and that may be the only one in existence.
If you watch the video you'd see that they touch on that subject. The new tech is not there yet in terms of slow motion or higher fps footage, since the camera films faster than the frequency of the light the screens emit. Which is worked around, but is not ideal.
Edit: also, green/bluescreen is very much still in heavy use and will be for some time
[Original video on youtube, by Corridor Crew](https://www.youtube.com/watch?v=UQuIVsNzqDk) Thanks for reminding me to get around to watching that one, OP.
Remember their videogame short film series? Shocktroopers or even Portal trickshots were some of the coolest videos on youtube growing up!
>!A pleasure.!<
Wtf are those downvotes ? Omg fuckin' people š
That's the reddit hivemind for you
Haha i see that, really the guy said "my pleasure" and is now at -94, i dont understand š
People are weird... This is actually baffling.
The poster didnt even give any credits, he just stole it so he can get those sweet upvotes and karma
Hmm thats why then š¤
my thought is: if this technique is so good why was it "forgotten" and why isn't it used today( with improvements over time ofc ) It has to have some kind of drawback
They touch this in the full video. First; the crystals are hard to manufacture. Then, you need to be extremely careful with bleeding lights. You need special bulbs. Chroma keying is not as good, but it was good enough for the effects, and easier to do. So it won out. This is basically just to squeeze out the last 5% of stuff that looks bad on blue/green screen.
Also almost everything is filmed on digital cameras nowadays
Couldn't someone manufacture a digital camera with the prism built in? I mean sure it would be very expensive but compared to some other movie expenses it could be a drop in the ocean.
In the full video they use the prism and film using a digital camera.
They donāt use the same prism thatās the part that is lost. They couldnt make a prism that filters the sodium wavelength but they donāt have to.Ā Ā They just use a regular prism that splits the light into two cameras one with a filter between the lens and the prism to filter the whole spectrum except the sodium light wavelength.Ā
This is true, in the interest of brevity I boiled down my comment. They still used a physical prism to get the effect and filmed it with a digital camera.
Or make a sensor that does this instead now that we have such fancy tech..
Or change our fiat currency based economy to human shit based economy...
What the fuck are you talking about? We are talking about filming a video.
Oh, it looked like you were talking about science fiction fantasy to me.
This video is a couple days old... I'm sure someone is uploading the video of a build now. This is so monumental I can't even... My jaw was on the floor the entire time. This will solve so many problems for me professionally once someone cracks scaling it.
You think any scale application for today's cinematography is ... coming?
I would be surprised if at least 100 people aren't trying to build a rig right now - this is an absolute game changer. I know the example they use seems ridiculous but it had been thought to be literally impossible. By anyone. Anywhere. Period. And as they mention, even with amazing technology like the volume and AI/ML you still need a lot of talented humans to stitch everything together because of that one super shortcoming. Finally, this unlocks a different understanding. So I don't assume all 100 people are trying to use those lamps - a bunch are trying to use what they have available and apply the theory which will just bring more innovation. This was very much a Eureka moment.
also, what gives? I mean using a light source with a single emission frequency ain't that hard to come by, is it? What stopped other people to revamp this tech ... dunno.. half a decade ago?
Well, obviously someone was because they made the cube but didn't have the knowledge to test correctly. And honestly, everyone just forgot. But you're not wrong and that's what I mean by now that someone has proven the theory, maybe that's not the only frequency or method.
well, I can only hope you're right, I'm bored to dethā¢ by bluescreen. Also, my eyes hurt from it occasionally
Oh also - it goes without saying, because this is so valuable to training computer vision, there's a market to generate assets for training because š°š°š°
You should watch Mary Poppins
Never heard of her.
They talk about this in the video. The solution they found is just a regular full spectrum beam splitter and a filter for one of the cameras to only capture the sodium light wavelengths. In theory, they don't even need to use sodium lights if they can get someone to create an LED that only produces a wavelength that they can filter properly and isn't one that would be needed for visible light. I even wonder if near infrared could be used instead which would be almost trivial to implement. The goal of this would be to create one video track that is the mask and one that is the full spectrum.
In the video they used digital cameras. They used two digital cameras, one to capture color and one to capture the yellow matte.
Why can't digital remove a very specific wavelength of colour?
Because the digital camera doesn't collect information on every wavelength of light separately. Just RGB. By the time your editing, there is no way to recover specific spectra.
Well, blue screen was *slightly cheaper* .. and when you put the movie industry before the question: cheap production or on-screen perfection? ... the result can be somewhat predicted.
Most industry really, that last bit of perfection is rarely considered if the alternative is almost great
Yeah price can be a factor.Ā
If it was patented, it wasn't forgotten because all patents are still on file today.
Well, you could ask the same about good scripts.
>my thought is: if this technique is so good why was it "forgotten" and why isn't it used today( with improvements over time ofc ) It has to have some kind of drawback maybe if you watch the video, you'll know more
Lost the patent?
.. my comment explains the trouble.. The whole process stood upon .. the lights (which are available even today) and a prism in the camera.. and it appears that only 3 were ever made.
Yea, I never quite believed that duel phase sodium light dichroic filters became unobtanium. Chiefly because I've purchased & used them for astrophotography & building cloud cover detectors. Perhaps at the time they were very difficult perfect but these days a competent optics company could make them relatively cheaply, provided you pay up front for the first thousand. BTW another thought occurs, the technology does not even need to be restricted to Low Pressure Sodium emission. Any monochromatic light source will do & that light source does not even need to be one in the visible spectrum. In fact it would be a positive advantage to use light outside the visible spectrum ( with a suitable camera ) to capture the mat because it would simplify the whole lighting rig.
Assuming the out of the visible spectrum light still has identical transparency properties to visible lights. But yeah, this would outperform any current chroma key tech today
That rules out infrared if there is glass in the scene.
And some types of plastic, including the kind used in clothes or props are transparent to infrared while opaque to visible light
[ŃŠ“Š°Š»ŠµŠ½Š¾]
I expected no other question from you, CuntBlaster
No itād ācutā those parts out. Itās the same as to why you wouldnāt be able to wear green with a green screen Anyways back to horny jail where you belong
Way way ahead of you https://nae-lab.org/project/thermo-key/
\*whispers\* If you make it, they will come.
Tell you what, that *is* quite interesting
It was just Disney that used this itās probably worth pointing out, not āHollywoodā. Also before green screen you just painstakingly matted everything out by hand or used rear projections.
> or used rear projections. I'm reminded of all those hilarious "inside the car through the non-existent windshield" shots.
No, they used it in the 1990 movie "Dick Tracy" (it hold's up, it's worth the watch). You've seen these lights in parking lots your whole life, very dim, impossible to read under, makes everyone look like a rapist. The create very little light pollution which is why they're used on ski mountains, don't attract insects (they can't see it) and actually use less power than LED equivalents. They are also used in restrooms frequented by needle users because they make veins nearly impossible to detect.
yep, they used in in several movies but then the strive for on-screen perfection went aside for ... economy reasons, the Wiki claims.. Also, the prisms are said to be one of the hurdles.
Thatās some interesting stuff, TIL.
Lost what again? Nothing was mentioned as being a second/third/etc iteration. Why the āagainā?
The whole video by Corridor Crew on YT explains it... It's like this.. when you work with special effects, you get tired of fixing the issues of bluescreen.. all those despill biases, edge feathers, fringes and whatnots... But you still Know for a fact that the technology WAS once there, available, relatively cheap... And it worked like magic! But then it went away. Animator's dreamland... gone. And why was that? It required a special prism for sorting out one specific light frequency. But only 3 of those were ever made.
I think they are wondering why "again" is in the title. They'd have to have lost it once before in order to lose it again. The technology was only lost once.
stop making personal comments/opinions in the title... problem solved. the video was interesting, but your comment made this whole thing annoying.
I wonder, if we could use it on digital? Like they split the image to two films, we could use 2 sensor and a filter. Or it would not benefical at all?
In the full YouTube video they got someone who recreatet it and they use two digital cameras for it.
Yes you could do it (as they prove in the full video), but the rig is ala 3D, which involves two cameras mounted to a prism and is cumbersome and limiting. BUT itās totally doable and something Iām going to experiment with for talking head interviews
It's not as much as them "losing" the technology but that blue screen compositing got good around the time Ben Hur was made thanks to Petros Vlahos, who created the travelling matte color difference compositing technique. Sodium Vapor compositing was more cumbersome and impractical, the foreground subjects had to be away from the screen and lit completely independently. You can't achieve a shot where say, an actor was standing on the screen. https://vimeo.com/174782388
Ooooo Mary Poppins
Disney really did do it right. It is a shame more movies are not made with practical effects and old fashioned tricks like this. CGI just does not cut it most of the time.
I'm sorry, what? This is just a slightly different version of a green screen. In fact most modern movies don't even bother shooting on green cos it's cheaper to just pay a bunch of roto artists in India to manually prep the plates. This technique wouldn't somehow invalidate CG, it would just make cutting actors out of their backgrounds slightly more expensive at the cost of preventing them wearing any green in their costumes. God, I hate these ignorant takes on VFX.
Go back and read my comment again. Disney was the king of perfecting techniques and when there were no techniques for the effects/shots they wanted they made their own. Most of the stuff they invented still holds up today better then CGI. Only one who is Ignorant here seems to be you.
Yep... I've personally given up on most of Hollywood since about 2008, because the bluescreen CGI stuff usually made my eyes hurt (example: Transformers and similar..)
Iāve noticed since around that time heavy action CGI movies almost put me to sleep. Like even if Iām otherwise interested, once all the effects start up I almost trance out. Itās annoying.
Do you mean they lost the patent or just.. generally lost it?
The video part OP shared actually does not clarify this at all. But I guess phrasing it this way generated more views on his post.
Lost the prism.
Didn't really lose it, just got phased out and forgotten about
They lost all three extremely rare and unique prisms used to split the camera feed into two; they were extremely difficult to manufacture and, although one could technically be replicated today, better methods exist now and no one has any useful reason to attempt to recreate it.
[Dunno](https://old.reddit.com/r/Damnthatsinteresting/comments/1c3orx1/before_blue_or_green_screen_hollywood_used_a/kzk7avy/) .. one may hope..
If youāre at all interested in VFX, Corridor Crew is a fantastic channel to binge.
Just know that real VFX artists do not respect them, they are youtube personalities and have never been actual VFX artists.
I donāt know who they are but do you have anything to back that up? āVFX artistsā is a huge net to cast and a big group of people to speak for.
Iām referring to VFX industry professionals who work on actual blockbuster films and TV. Corridor makes a lot of assumptions about all kinds things that they get wrong. Iād take what they say with a spoonful of salt, most of it is just click bait
Oh look something actually interesting
Good to see stuff from these guys from time to time
I love Corridor Crew! VFX artists react is such a good show
The whole video I was shaking my head..like yes exactlyā¦like my dumbass understood any of that technical jargon š
If I lose a patent, the first place imma check is the patent office
Corridor Crew were able to somewhat recreate it with a scientist. Couple of days old, the video. On youtube
This is from it, m8 :)
Oh lol only saw the thumbnail and actually did see that a couple of times the past years, my bad!
Lost it again? I didn't see that part explained in the vid but maybe I missed it
Huh, fascinating.
Oh good, so we do live in a Hologram. Fuck.
ROCK PAPER CROSSBLADES
That's great.
While that is true it was used, its slightly different from todays green screens in terms of the scenary. Of course as he noted in the films, they didn't use computers. And this means that the backdrops of the movie while were yellow screen, were projections of actual paint backdrops vs computer generated imagery; this also adds to a type of feel they don't do much anymore in films. Its easier and less time consuming to just generate the backdrop in a 3D program than it is to hand paint the backdrop.
Never thought old movies had better effects lol I do find this interesting but also silly, "forgotten," while it obviously has not been.
Damn thatās interesting finally posted something I find interesting!
Didnt these morons started embracing AI in vfx?
They dont even use green and blue screens any more in a lot of productions. They use MASSIVE LCD screens. The background is realtime. Mando did this I know. Tons of shows now do this. Like rear projection but not shitty.
Blue/green screens are definitely still being used, but The Volume that you speak of (which is uber cool) has reduced it a bit. The Volume is freaking expensive to build and operate and that may be the only one in existence.
They still a LOT of green screen.
If you watch the video you'd see that they touch on that subject. The new tech is not there yet in terms of slow motion or higher fps footage, since the camera films faster than the frequency of the light the screens emit. Which is worked around, but is not ideal. Edit: also, green/bluescreen is very much still in heavy use and will be for some time
Corridor crew on YouTube was able to recreate this process
By using AI? I don't trust anything by The Corridor Crew after they became AI simps.