"D Yuniskis" wrote in message
...
Hi Arfa,
snip

- which phased out incandescent bulbs with a pearl diffuse envelope. 60
watters were to be the first to go, followed by 100s. Clear envelopes
however, were to remain available, at least for the time being. So all

What was the rationale behind phasing out the 60's before the 100's?
Frosted before clear?

AS far as I have been able to ascertain, the reasoning behind earlier
phase-out of 60s, was that it was felt that CFLs had reached the point where
they could substitute for them in terms of equivalence of light output,
whereas they still had some way to go to be able to make that claim for
100s. As to why pearl before clear, I have not been able to find a
definitive answer to that one. I have seen it suggested that the pearl
envelope is more inefficient than the clear one, in that it blocks more of
the light output of the filament, causing it to be lost as heat. I'm not at
all sure that I believe that as a valid reason, and subjectively, I've
always thought that a pearl bulb in fact *appears* brighter than a clear
one. Certainly, the fact that the light is diffuse, seems to make it less
prone to generating sharp shadows, and from a purely aesthetic point of
view, pearl bulbs look much more attractive in fittings where they are
visible. Clear bulbs always seem to conjour up that 'seedy' feel that you
get from old thirties gangster and private eye movies.

Arfa