Halide shimmer effect ?

ahayes13 · May 27, 2009

One of my uv glass shields on my 250 de's burst yesterday. so i was without a light on the left side of my tank. and cant make it back to my lfs til next week.

So i put up a temp. light for the week and put up a spider reflector with a 150 se 20k ushio on a pfo ballast.

my right side is my usual which is a lumex max elite reflector with a 250 de 14k phoenix on a pfo ballast also.

i noticed the temp light, left side tank, has a LOT more shimmer effect. So im wondering what aspect of the temp light is causing so much more shimmer. The bulb or the reflector? whats your thoughts?

Ldogg · May 27, 2009

probably the reflector.

ficklefins · May 27, 2009

I'll play along. What about the fact that one side is a SE with no UV glass, versus the other side which has the UV shield. It may lose some of the shimmer as it passes through the glass.

roshi719 · May 27, 2009

I would guess that it is from the reflector. Shimmer lines come from point sources of light. The whole point of a reflector like a lumen max is to disperse the light and give as even coverage as possible. JMO

roshi719 · May 27, 2009

DE with UV glass is the same as SE though. The outer glass of the SE bulb is the UV shield. Or at least that is my understanding of it.

Viva'sReef · May 27, 2009

roshi719 said:
DE with UV glass is the same as SE though. The outer glass of the SE bulb is the UV shield. Or at least that is my understanding of it.

this is correct!

cloakerpoked · May 27, 2009

I'm guessing it has to be the reflector. May also have to do with the size of the bulb, but that's just stating the most obvious difference between the two bulbs themselves

roshi719 · May 27, 2009

Anyone who has tried to take top down pics under a lumen max or the like can tell you there are multiple bulb reflections on the surface vs one or two from a parabolic type reflector. Multiple bulb reflections equals multiple point sources of light. I'm thinking all the shimmer lines from all the different point sources are effectively cancelling each other out.

EliteReefs · May 27, 2009

roshi719 said:
DE with UV glass is the same as SE though. The outer glass of the SE bulb is the UV shield. Or at least that is my understanding of it.

this is true however for most the glass used for a DE is much thicker then what surrounds a SE. i would think it this case it is just the reflector. one is spreading out the light a bit more and the other has it a bit more concentrated