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Unread 03/12/2009, 09:45 AM   #261
lynxvs
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Join Date: Sep 2008
Location: MA
Posts: 189
Quote:
Originally posted by CJerome21
I am interested in hearing more about the distance the LEDs are mounted from the water surface in relation to using or not using optics.
Soundwave what is the distance from your LEDs to the water surface and the same for Lynxvs?

I am planing builds for my two nanos and right now my PC light is about 2.25 inches off the surface.

As you probably know optics will concentrate the output of the light source into a narrow beam so the light intensity is greater farther away but with a narrower beam. Of course this reduces the "spread" of the light to what soundwave calls the "spotlight effect"

There is something else going on when light strikes the surface of the water called "Snells Law" what this means is light will be refracted or bends when it hits the surface of the water so it works sort of like a lens but not as good.

This is only true when the light source is very close to the water. The ideal distance could be calculated I assume.

If you use optics you can raise the light and depending on the width of the beam have the same or greater light intensity with the same light spread. Remember even though you have a narrow beam the light will spread the higher you raise it.

I have tried hanging the light at 6" , 10" with optics and 2" without optics.


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