When I did the Q&A interview with lighting designer David Hersey for the December issue of Live Design, upon his return to Broadway with the recent revival of Equus (starring Daniel Radcliffe aka Harry Potter), I asked him abut the use of LEDs on stage, and he admitted "they seem to be here to stay." In addition to using LEDs to help accent the set, Hersey also pointed out: “The horses' heads each have two 1W, 4.5V white LEDs — on separate channels on a wireless dimmer — used in the blinding sequence.”
I was curious about these LED eyes and asked programmer Rob Halliday what they were exactly, and this is what Rob reported:
“The summary is that there are six horse heads, each of which has two white LED sources, one for each eye. The sources are controlled by RC4 wireless dimmer modules; these are remarkable products offering two individual dimmers inside a tiny package which Jim Smith at RC4 Wireless Dimming supplied at very short notice when everyone decided that new blocking meant the eyes had to be wireless for New York (in London there was a cable running to each horse and they detached the cable before leaving the stable).
“Matthew Burstein at Acolyteled was employed to create new eyes for New York (as we'd run out of spares of the London sources and the fitting we used from London had been discontinued). Each eyeball is a Lumiled K1 5500k white LED with Fraeon 8-degree optics. These and the RC4 dimmers are run from custom battery backs made for us by Burstein, our production electrician Steve Cochrane, and show electrician Jeff Turner. Each RC4 pack can individually control two loads—so we now have separate control of each eyeball in each head, which we didn't have before.
“In London, the eyeballs were removed for scenes where they weren't required; for New York we leave them in the heads. This decision was partially made on practical grounds— it's harder to remove them because we now have the radio receiver etc —but everyone also quite likes the appearance of the front of the light sources in the horse's eye sockets.”