just saw this pic...any ideas on how?

...how does one make a prism? also one that makes an arc insead of the straight "dark side of the moon" style? ....

Wel you start with a lot of concrete and steel bars. You make a big wall, Oh wait, that's a prison....
There are a ton of ways in which you could build your own. From grinding a single piece of glass to building a conplex multi pane system. I wish I knew more about Optics, but if you have the right tools this isn't as hard as it sounds / appears, just expensive.

And they said only God could make a rainbow ......
 
I'm not entirely certain that interview about the technology uses the right terminology? After thinking about it a while, I don't know that I believe a prism is used to make a curved rainbow on the projection screen... that would be an incredibly difficult thing to do... and the sort of thing you would send out to an outside optics company, not manufacture in your prop shop with the same tools you use to cut acrylic, or the like...

Maybe we're just talking about a custom color gobo, and he heard the lighting designer say it's 'like a prismatic gobo?' And then mis-spoke while bragging about the LD's work and called it a prism?

I'm just thinking that light bends IN a prism then travels in straight lines afterwards... if light curved... well... I'd be a lot more excited about lighting box sets. ;) Now, it probably is possible to take a long prism and bend it into a curve so what would be a straight row of prism projection gets projected as a curved line... but this would be incredibly difficult... again not the sort of thing you do by just heating up a bar of glass with your torch and grabbing it with the vice grips... To get that perfect of a curve, with the prismatic effect perfectly inline and not distorted by the curving process at any point.... We're talking nasa sort of optical manipulation there... and even they sometimes have to go up and fix their optical mistakes. ;)

I'm not saying it couldn't be done... but it seems like creating the rainbow you want with other means and then finding a bright way to project that color image makes far more sense than trying to design a really high quality curved prism and then figure out how to get enough light through it, to the right place, with no light leak.... I just think most theatrical designers would use one of the existing technology solutions that could do the same thing, probably better and with more certain results... but then.. the Met does NOT employ MOST theatrical designers....

Art Whaley
Art Whaley Design
 
while it is true that light travels in a straight line after exiting a prism, one must remember that the prism doesn't have to be straight.
Ever see the effect known as "halation" coming from an ERS ? the curved edge of a lens can, and does create a rainbow arc applying this observation with a highly motivated team of well paid technicians and engineers gets you a curved prism rainbow effect.
 
while it is true that light travels in a straight line after exiting a prism, one must remember that the prism doesn't have to be straight.
Ever see the effect known as "halation" coming from an ERS ? the curved edge of a lens can, and does create a rainbow arc applying this observation with a highly motivated team of well paid technicians and engineers gets you a curved prism rainbow effect.

If I am not mistaken, halation is the stray light that you get from an ERS unit outside of the field. Chromatic aberration is the colors that you see on the edge of the beam and is caused by the fact that not all wavelengths of light bend the same amount when they pass through a lens.
 
If I am not mistaken, halation is the stray light that you get from an ERS unit outside of the field. Chromatic aberration is the colors that you see on the edge of the beam and is caused by the fact that not all wavelengths of light bend the same amount when they pass through a lens.

I, of course, was refering to "Chromaticly Aberrant Halation" which is a combination of these effects.

See when you've been in the business as long as I have.......
:rolleyes:

Thank's Ice, for keeping me honest.
 
I certainly have seen chromatic aberration create a curved line with a rainbow effect to it, and I can imagine that a prism could be bent to cast a curved line of colored light.... but it would be a pretty serious task to get just the curvature you wanted... and the techs at the Met aren't optics manufacturers....

And in the end, a custom made curved prism, mounted in a custom light source that doesn't throw tons of spill light around the edges of the custom made curved prism, just gives you a way to generate a color image for front projection, and I can't come up with any reason to go through all of that trouble when you could design the exact curvature and color distribution you wanted in photoshop, and send it off to be made into a custom glass gobo for the brightest ERS you can get your hands on? Or dump the image into the video projection system that's already providing scenery and special effects in your show....

There may very well be a reason... or they may very well have done it just because they can... but I'm just not convinced that the article reports accurately about that technology, and so I'm not convinced that the mystery is entirely solved. :)

Art Whaley
Art Whaley Design
 
... and the techs at the Met aren't optics manufacturers....

.. but I'm just not convinced that the article reports accurately about that technology, and so I'm not convinced that the mystery is entirely solved. :)

Art Whaley
Art Whaley Design

Don't be so quick to poo-poo our brothers at the Met. 'Course they didn't invent the effect. Take a look at this article. NYTimes articlePDF
Ok it's long and mostly boring, but scroll down to the second to last paragraph, Wait scroll back up to the top of the article where they talk about the '88 production at the Met < which is what the article is about> is using the original scenic designs and SPFX from the original production in 18XX I forgot the date. Ok now scroll down to the bottom of the article, second to the last paragraph they describe a technician shing a light source through a stereopticon then a curved prism, then a slit in the back of a piece of scenery. Pretty niffty!

Just thought it was interesting. Them there Theatre lighting guys can be pretty smart at times.
 
My only thought is that unless someone invented the light knife, there should be a second rainbow at some point past the scrim.

Mike
 
My only thought is that unless someone invented the light knife, there should be a second rainbow at some point past the scrim.

Mike

When you have a budget like the Met's, you can afford to buy LumoSuck by the case.
 
When you have a budget like the Met's, you can afford to buy LumoSuck by the case.

Yeah, but not even the MET can change the laws of physics (I have done a couple of "unlimited" budget shows and the laws of physics can't be bought).

Mike
 
Yeah, but not even the MET can change the laws of physics .....Mike

Spock and Scotty did it by initiating a cold start-up of the anti-matter reactor on Star Trek, once.... If Scotty can do it, I'm sure the boys in Local #1 can.
:mrgreen:
 

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