Diffusing LEDs

I am currently building an LED matrix, and would ideally like to diffuse the light from the LED into maybe a square or rectangle shape(using some sort of border). What would be the best way to do this? I've tried using tracing paper, normal paper, fabric etc. to try and spread out the light, but it always seems to create the 'circle' which comes from the top point of the LED rather than spreading it out.
Any help would be gratefully appreciated.
Thanks :).

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bertus52x116 years ago
Ok, it's not rectangular, but why not use PingPong balls? They look very cool!
I have used it in my I'ble: https://www.instructables.com/id/after-Dinner-reaction-Time-Tester
Kiteman7 years ago
Hey, look, there's an Instructable for diffusing LEDs!

How about that...
willww (author)  Kiteman7 years ago
Sorry, I forgot to mention, I've seen a lot of tutorials regarding this, but I intend to place the top cover quite close to the LED (about 5mm away) and wondering if it'll still create that 'circle', plus I'm doing it with about 500 LEDs so need a better solution than sanding each individual one. The hot glue method seems a good start, but wondering if those 'diffuse sheets' are any good or if somebody has a better method.
Kiteman willww7 years ago
Not knowing your exact plans, how about pointing your LEDs the "wrong" way? 

Diffuse them by sanding (mass-produce them by clamping a sander in a vice and hold the LEDs against it, one at a time), then arrange them pointing at a matt white surface, such as paper, with the "wiring end" pointing at the surface you want to illuminate.

That should further diffuse the LEDs, so that the circles over-lap.

willww (author)  Kiteman7 years ago
Thanks for your reply. Unfortunately the LEDs have already been soldered (which took a very looooong time) :( I've included a picture to show my project. The LEDs are all placed facing upwards, and are currently bare with no housing. I plan to have a 'box' for each LED to light up a space such as a square or a rectangle and currently finding the best way to do this. I've soldered the LEDs already because I thought the dispersion of light wouldn't be a problem and intended to just keep the 'circle' view of the LED as it is, but open to experimenting on the best look.
The best way I've found so far is to make a cardboard box for each LED and fill the end in with white/clear glue.
Kiteman willww7 years ago

My last idea, then, is to fill the compartment around each LED with something like crushed glass (maybe shards of acetate?) to reflect the light around as much as possible.
willww (author)  Kiteman7 years ago
Never thought about filling the compartment, I might give that a go. If anybody else has any ideas, would be a great help.
zascecs Kiteman7 years ago