Chandeliers with prismatic glass are another problem area for LED lighting. My home has two such fixtures, previously populated with nine 40-Watt incandescent lamps each.
That's a lot of power dissipation (360 Watts), particularly since one of the fixtures was on up to 12 hours per day (4KW-h almost daily for that).
So I replaced all nine bulbs with TCP LDCT3WH30KCC 3-Watt (15 W incandescent luminance equivalent) 3000-K 80-CRI bulbs. 27 Watts, down from 360.
Excellent energy savings, excellent dimmability (better than the incandescents), but all those beautiful violet, green, blue, gold and other various facets of color from the prismatic glass were just gone -- collapsed down to a cold white; as if the glass weren't prismatic anymore.
I do not understand why I don't see at least some narrow-band stripes of some few individual colors.
So I put back just two 40-watt incandescent bulbs. That was enough to bring back a nice refractive color spread from the prismatic glass. The dissipation is up to 91 Watts from 27 Watts, but it's beautiful again.
Energy problem resolved satisfaction (75% reduction), while keeping the aesthetics alive too.
That's pretty interesting. I bet it has something to do with the polarization of light. If so a bulb like the Cree (with its glass casing) might help, although it might look goofy in that particular fixture.
I doubt it's the polarization. More likely it's that the incandescents are point, or line sources (non-frosted bulbs), but the LED's are much wider - so you are still getting colors, but since you have multiple color in multiple spots they overlap, mix, and are back to being white again.
Try to get LEDs that have no diffuser lens in front, since the LED itself is a point source.
That's a lot of power dissipation (360 Watts), particularly since one of the fixtures was on up to 12 hours per day (4KW-h almost daily for that).
So I replaced all nine bulbs with TCP LDCT3WH30KCC 3-Watt (15 W incandescent luminance equivalent) 3000-K 80-CRI bulbs. 27 Watts, down from 360.
Excellent energy savings, excellent dimmability (better than the incandescents), but all those beautiful violet, green, blue, gold and other various facets of color from the prismatic glass were just gone -- collapsed down to a cold white; as if the glass weren't prismatic anymore.
I do not understand why I don't see at least some narrow-band stripes of some few individual colors.
So I put back just two 40-watt incandescent bulbs. That was enough to bring back a nice refractive color spread from the prismatic glass. The dissipation is up to 91 Watts from 27 Watts, but it's beautiful again.
Energy problem resolved satisfaction (75% reduction), while keeping the aesthetics alive too.