"Bob Urz" wrote in message
...


Bob Urz wrote:



Arfa Daily wrote:


Here's a really interesting site

http://www.oksolar.com/led/led_color_chart.htm

Follow the various page links to the chromaticity chart, and " More
information on LEDs" at the bottom. I didn't realise that they were
already in use in street lighting. There is mention of higher colour
temperatures improving human night vision. There is also an interesting
LED colour chart, which shows one at 4500K called "incandescent". A
couple of years back, I was in Disney when they put on a show in front
of the Magic Castle. There was a stage spot set up on the top of a pole,
projecting a brilliant white beam of considerable strength. I didn't
take much notice of it, until it suddenly changed colour. During the
show, it produced a whole range of colours, but I couldn't see that the
enclosure was anything like big enough to accommodate a coloured gel
wheel. I remember wondering at the time, if this had been implemented
using very high power RGB LEDs. I suppose that it is also possible that
it could have been a plasma lamp with dichroic mirrors and LCD panels.
Are any LEDs actually powerful enough to make stage lighting from ? Can
they be mounted in any way that allows light collection and direction
through beam forming optics ?

Arfa

LED's are being used for stage lighting, but not in the high power movers
or Ellipsoid's (YET). WHat you probably saw was a martin MAC2000
or such at disney. They have full color mixing onboard VIA DMX


It didn't look quite like that and didn't have remote move capabilities, but
was remotely controlled in as much as the colour changing and intensity, so
I guess it was on a DMX bus. It was on the top of a pole, so clearly made to
work in outdoor conditions, and small and squat, which was made me think
that it used technology that I hadn't seen in that application before. I
also seem to recall that I was particularly struck by the range and
intensity of the colours it produced. Guess I'll never know for sure. The
links contained some interesting stuff on high power LED lighting. Seems to
me that the LEDs themselves have pretty much evolved to the point of
usefulness, and that it now needs more developments in the optical part of
the equation, and colour temperature rendition. BTW, did you get the partial
schematic for the 'HT70 that I sent you, as requested in your post of a few
days ago ?

Arfa