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I have come across different techniques for diffusing colors. I found Fresnel Lens can be use for diffusing RGB led colors.Is it worth using it or not. I have tested transparent plastic and some lenses but they are not good. Only white paper I found is best.

If it is worth for using (Fresnel Lens)can you guys tell me about supplier for it as well.

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  • \$\begingroup\$ seems pretty OT \$\endgroup\$ – Scott Seidman Mar 5 '13 at 15:25
  • \$\begingroup\$ This is either a shopping question (off topic), or not a good fit because we can't answer whether it is worth it or not. \$\endgroup\$ – Olin Lathrop Mar 5 '13 at 16:20
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More data please.
Power, target, distance, size ... application ?

Fresnel lenses have the advantage of beam shaping with relatively minor optical losses - about 10% typically. The same applies to TIR lenses and reflectors - both of which MAY do what you want. White paper achieves its superior result with a very high optical loss. This may be unimportant or crucial depending on application.

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  • \$\begingroup\$ Hi there: I want diffuser for RGB led. At the moment I am using white paper for it. My colleague told me to use Fresnel lenses. I want to put diffuser on led. Is it possible with Fresnel lens. So I can see mix color from top of led. I tried to search on it but cannot find data regarding mixing RGB led colors. \$\endgroup\$ – MZF786 Mar 5 '13 at 15:00
  • \$\begingroup\$ That's what you told already, but Russel wants to know what your total setup is for. Are you presenting one nice little colored dot, or are you illuminating a theatre (to mention two extremes)? \$\endgroup\$ – Wouter van Ooijen Mar 5 '13 at 15:02
  • \$\begingroup\$ At the moment nice little colored dot. \$\endgroup\$ – MZF786 Mar 5 '13 at 15:03
  • \$\begingroup\$ I get your point. I need a lens or diffuser which diffuse light first. Then spread that light as well. I hope I have cleared your confusion. \$\endgroup\$ – MZF786 Mar 6 '13 at 11:25
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I very much doubt that a fresnel lens will work for you in the diffusion of the rgb diode as the diodes are discrete and slightly separated... a fresnel lens would have to be fairly far from the LED in order to not create a bunch of little rainbows.

but a white paper and a fresnel lens would work, or perhaps some sort of white paint on the back of a lens... you need something to break up the directionality and cohesiveness of the three light sources or else you will end up with the multi-color shadow effect: like this

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  • \$\begingroup\$ I have tried white paper with lens though it has some loss but still works best till now for me. \$\endgroup\$ – MZF786 Mar 5 '13 at 16:10
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Here are some suggestions:

  • LSD - no not that type - Light Shaping Diffuser - bought in sheets

  • Opal glass - has some patterns

  • ground glass - readily available

  • etched glass - readily available in a local glazier (glass shop)

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  • \$\begingroup\$ guys could you please vote my question. \$\endgroup\$ – MZF786 Mar 6 '13 at 11:23

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