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How do led infinity tunnels work?
BobA:
I am trying to build one of those light boxes where you look in and the leds (or bulbs) stretch on to infinity. My original idea is that the back is a mirror and the leds are in front of that. The leds will be connected to a sequencer for patterns and spaced around the outside edge inside the box. In front of the leds is a smoked half silvered mirror facing inward. Half silvered mirror or 1 way glass are just terms I thought might apply. I am not sure what it is sold as or where to actually buy it.
Does anyone know if my idea is correct before I go out and start buying pieces? I have never actually had one that I could take apart so I am guessing.
Any input would be appreciated.
Thanks
BobA
planetjay:
Front is a 2 way mirror. Some light reflects back in, some comes out. Back is a regular mirror. I have never seen one use LEDs. The reason would be that light bulbs cast light in all directions. LEDs only send light in a narrow cone.
However if you mounted the LEDs IN the back mirror it might work. Also note that mirror angles are very hard to get right.
BobA:
--- Quote from: planetjay on May 26, 2003, 08:05:37 pm ---Front is a 2 way mirror. Some light reflects back in, some comes out. Back is a regular mirror. I have never seen one use LEDs. The reason would be that light bulbs cast light in all directions. LEDs only send light in a narrow cone.
However if you mounted the LEDs IN the back mirror it might work. Also note that mirror angles are very hard to get right.
--- End quote ---
Thanks I forgot about the LEDs being directional. Maybe a christmas light string may not be a bad idea. I am looking to put one on a jukebox.
BobA
RandyT:
Just remember that whatever you use, the brighter it is, the better it will work.
A half silvered mirror (beamsplitter) that has a 50/50 coating on it (without accounting for absorption and using a theoretical "perfect" mirror) is going to let:
50% through on the first "ring"
25% on the second
12.5% on the third
6.25% on the fourth
3.125% on the fifth
and so on.......
In reality, it will be less. How much less depends on the quality of coatings used.
I'm thinking that PJ's idea of mounting superbright (10,000mcd) white LEDs through from the back of the mirror would be an interesting thing to try. When you look at those things straight on, you see green spots for about 15 minutes afterward :)
Oh, and you'll want to use a first-surface mirror and make sure the reflective coating on the beam-splitter is facing inside.
RandyT
planetjay:
I'm not say that drilling a mirror would be easy either. But I woul dlike to see it.