How to make a panel of LEDs appear to be a single source infinitely far away

Question

I have a square panel of 100 LEDs (a series of LED strips). I would like to use some sort of optics setup to make this panel emit light that looks like it's from a single source at infinity.

Is this possible with a diffuser / fresnel lens type setup?

The difficulty with achieving the look of a highly distant light source is a key proof for the fact that the moon landings were not faked in a studio — Jonathan R Swift, Feb 09 '20 at 19:11
Really, Jonathan ? And of course the "Zapruder film " is real too, right ? ;-) — William Hird, Feb 11 '20 at 04:20

score 1 · Answer 1 · answered Feb 09 '20 at 22:55

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Any image or object placef at the focal point of a convex lens will by projected out to infinity on a cylindrical beam of light.

Using an objective convex lens to focus the LED lights on the focal point of the projection lens will do that. the smaller this objective image the closer the outgoing beam of light to light coming from a single source far away.

answered Feb 09 '20 at 22:55

kamran

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So would I need a convex lens per LED? – Amit Deshwar Feb 11 '20 at 18:38
No you need two convex lenses. One to focus all the LEDs on the focal point of the other which will then project the beam. I have seen equipment which was like a 24inch square box with 3 color LED screen inside with lenses, and it would project images and movies on a big wall. – kamran Feb 11 '20 at 19:27

score 0 · Answer 2 · answered Feb 15 '20 at 20:42

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You need a proper Fresnel lens, and then diffusion. This video explains it very well (but it does build on a tv display panel, rather than a build from scratch): https://www.youtube.com/watch?v=8JrqH2oOTK4

answered Feb 15 '20 at 20:42

KlaymenDK

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How to make a panel of LEDs appear to be a single source infinitely far away

2 Answers2