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Re:Metal Halide Lights



IDMiamiBob at aol_com wrote:

> Raymond writes:
> 
> > Acutally I'm sure if the MH lights over my tank will reach the bottom of my 
> >  tank, my main concern is does it matter if it's directly above my tank or 
> >  slightly tilted so the lights won't be in my eyes when i'm looking at my 
> >  tank... is that more clearler?
> 
> As long as the majority of your light is entering the tank, and it is getting 
> to the bottom, it really doesn't matter what angle they are at.
> 
> Bob

But remember that reflection of ligth at the water/air interface gets more 
important for shallower angles of incidence. If the ligth fixture relies 
mostly on specular reflection, small tilts from the vertical would not be
important, but larger tilts, say 45 degrees or more, will cut the ligth that
actually makes its way to the bottom by a large factor, 2 or even larger. If
the ligth fixture relise mostly on diffuse reflection, the tilt  becomes less 
important since most of the ligth is going to be wasted by reflection anyway.

- Ivo Busko
  Baltimore, MD