In article , Ian
Stirling writes
Tim Mitchell wrote:
In article , Ian
Stirling writes
Chris Hodges wrote:
The OP might be better off with an RGB array of LEDs (which is also more
efficient) as you can balance the colours, but that would be DIY(!)
and/or expensive.

I have R/G/B 38W fluorescant lights, that I still mean to make into a
variable colour lighting fixture.

You get orrible coloured shadows if you do this (with any discrete
sources of R G and B), unless you are a long way from the object being
lit. It is also pretty much impossible to get any decent sort of white.
(I've designed several colour mixing fixtures for people, both
fluorescent and LED, and all suffer from this problem).

There is no reason that they have to be.
It's just that the needed diffusing optics are bulky, and a bit annoying to
design.

As to being impossible to get a decent white, I suspect you may be right -
only three phosphors doesn't help, or the relative low power of the red tube.

The commercial fluorescent colour changers include a white tube (plus
RGB) to get round it. A lot of the LED fixtures are being changed to
include amber LEDs for the same reason.
--
Tim Mitchell