Suggestions Wanted on Diffusing an LED bulb

Paint the surface of the bulb with a gold Highlighter. That should work. I have done that with bulbs inside our RV trailer and it worked to both spread the light, and dim it a little.

Jeff

@G3750 posted:

I have an application where I am placing an LED under a painted translucent surface inside a 4" wide diameter canister.  When I turn on the current, I tend to get one bright point of light.  Any suggestions as to how to diffuse the light, spread it around?

I had a similar problem when I replaced the incandescent E-10 base bulbs in my passenger cars with what turned out to be 'spotlight' LED screw-base bulbs, especially in the dome car. My solution was just to superglue a small square of paper to the tip of the bulb -- it both diffused the light coming out of the tip, and reflected more of the light out toward the sides and downward. I suspect it reduces the total light somewhat, but it solved my spot-of-light issue and the cars look more evenly lighted.

Lot's of options on the big A site.

https://www.amazon.com/light-d...=light+diffuser+film

Overkill for a small project. I would try some clear paint like Tamiya.

I find that normal white printer paper does an excellent job.

@gunrunnerjohn posted:

I find that normal white printer paper does an excellent job.

Yep, that's what I used for the superglued paper fix I suggested above.

@Steve Tyler posted:

Yep, that's what I used for the superglued paper fix I suggested above.

Guess it's a good idea.

I also have used white paper with success.

Translucent plastic usually is the answer. Is there a chance your LED doesn't have a wide enough beam angle? Not sure if "beam angle" is the right word but I mean the angle the light shines.

@gunrunnerjohn posted:

Guess it's a good idea.

Well, I guess you *could* say that that proves great minds can be on the same page? [Sorry/not sorry! ]

Apologies -- wasn't trying to step on your post, just attempting to rectify my omission in not mentioning the type of paper that worked for me . . .

I use the plastic from milk bottles. That works well and the price is right (except for the milk ).

@BillYo414 posted:

I also have used white paper with success.

Translucent plastic usually is the answer. Is there a chance your LED doesn't have a wide enough beam angle? Not sure if "beam angle" is the right word but I mean the angle the light shines.

In my case (which sounded similar to the OP's situation), the bulb was deliberately shaped to focus a beam of light in line with the bulb -- it's designed for use as a flashlight bulb replacement, and thus puts most of the light out in a tight beam. For a relatively omnidirectional LED, I agree that a translucent shield should do just fine, but I needed something dense enough to blunt the obvious 'spotlight' effect. A small square of regular printer paper did the trick for me . . .

I use the white paper with my flickering firebox boards to diffuse the pinpoint look from the group of LED's.

@Steve Tyler posted:

Apologies -- wasn't trying to step on your post, just attempting to rectify my omission in not mentioning the type of paper that worked for me . . .

Steve, absolutely no apology necessary, I was just having fun with you.

LED's are directional in nature as they are a FLAT Element that is inside the case.

LED's that have spread beams usually have multiple elements placed on angles but the size requirement for that would not work well for our applications.

I had a similar situation as the OP. I pointed the LED in the opposite direction towards a piece of reflective foil. It may require you to shape the foil into the exact beam you want but with a little trial and error, it worked out perfectly.

A tip I saw from Evans design, if you're using 3 or 5mm leds with the rounded top is to lightly sand the top to a flat.  This helps somewhat from my experience

@Kenjr posted:

A tip I saw from Evans design, if you're using 3 or 5mm leds with the rounded top is to lightly sand the top to a flat.  This helps somewhat from my experience

For my flickering firebox PCB with the round top flickering LED's I knock the whole curved top off on the grinder.