LED opticals

[Vermino]

Do I need optics on my LED's if the LED's are less than a 3/4 inch from the surface? It's only 6 gallons but even if it was thirty, sixty, two hundred and twenty billion gallons, aren't opticals for when your LED's are hanging and you dont want spotlight effect.

[shrimpNewbie]

No the optics focus the beam, meaning less spill you can get 90 degree optics if it makes you feel better and ime the led I tried had more shimmer when focused than when i took the optic off. Granted the led I'm talking about is probably 60x more powerful than what you would need on a 6g

[Hoppy]

I think the ideal LED light would have the cone of maximum intensity (about the middle half of the full cone of light) intersect the front and back glass more than half way down in the tank. So, it is the distance from the LEDs to the substrate that determine whether an optic is a good addition, and what cone angle optic is best. I get shimmer without using optics, but it is subtle. The light reflected off the water surface to the wall shows the most shimmer, but there is some at the substrate too. A single LED gives the most shimmer, with or without an optic installed. As you add more LEDs, they tend to wash out each others shimmer effect. (Shimmer is shadows from the ripple on the water surface, so additional LEDs shine light on each others shadows.)