take a look at this video around the 58 second mark and beyond: http://www.youtube.com/watch?v=T_3_je4gfh4 ...how do they make the writing disappear and appear within the metal?
It's not metal. Probably see-through, painted-on, plastic. The leds within, appear through the lightly painted plastic while the construction ensures that the light will come through only the letters and not the rest of the ring. Very easy actually (especially if you are a prop maker).
In the video it sounded like there was some clicking going on when the ring "illuminated." Another possibility is the use of UV activated fluorescent paint and a UV flashlight or other light source.
The video appears to be a CGI creation, but the comments thus far are good explanations of how it could be done. If I were to describe a way of doing it I'd 3D print the ring in something like Shapeways' Frosted Detail and have it hollow. For the main body of the ring I'd have something like a 4 mm wall thickness and for the lettering I'd have a 0.5 mm thickness. I'd install an array of yellow and orange LEDs for the lighting. I'd polish the outer surface and have it vacuum metalized in 24k gold. The coating of gold would only be a few atoms thick so that light would go right through and it would work exactly like how a two way mirror works.
pretty sure it's real based on: http://www.iloveswords.com/LOTR_SauronRing.html and: http://www.ebay.ca/itm/Master-Replicas-LOTR-THE-ONE-RING-OF- SAURON-PROP-REPLICA-/330935207846?pt=LH_DefaultDomain_0& hash=item4d0d4687a6 ...but thanks for the info. Pretty cool tech. Someone here should do it!
Well then that guy needs to be sent to YouTube jail for being the worst cameraman EVERRRRR! HAHAHA! :laughing: