How to evenly diffuse light?

[jpb]

I am wanting to build a small "glowing" star, maybe 6" high that will sit on top of a 6' tree. I was planning to build it out of corro and light it internaly with some RGB LEDs.

My question is, how do I build the front face so that the light diffuses evenly and the star appears to glow? I have tried using corro but it is a bit dim and the internal ribs show up. I split the corro and shaved off the ribs but there were still lines showing up where the ribs were.

Years ago I made the front face of my tune to sign from using clear perspex with a mist coating of spray paint as a diffuser, is still the way to do it?

TIA, Jon

[dirknerkle]

You could also take a piece of Lexan or other plastic sheet designed as window replacements, cut out your star and sandpaper one side...

[LabRat]

I just picked up a "shelf liner" at a local store. It's a pre-cut designed to sit atop of the "open pantry shelves". It's a thin sheet of rigid plastic (so it rolls up.. but when unrolled layed flat). It comes "frosted".. but perhaps not frosted enough. My plan was to try and use it as part of my son's halloween costume. If the LED's are too close, you see spots. At about 2" away, it was a nice even glow. I'm considering double (or triple) thickness, to try and get the diffused "glow" effect required.

Edit: Oh yeah.. $2.00 for 2 liners... 13"x17" if I recall correctly.
ps. Pretty sure you can get "spray on" frosting, as well as peel and stick frosting, for covering up bathroom windows.

[kayjay]

The reason why the "ribs" are showing up is because your lights are too close to the coroplast. You need brighter leds and mount them approximately 2 1/2 inches from the white coroplast surface. Build up the sides of your star using strips of coroplast. Take a look at the holidaycoro.com site as a reference.

[jpb]

Thanks for the replies. I will try with my LEDs further back but I don't think they will be bright enough.
I think the peel and stick frosting on some perspex is the way I will end up. Funny thing, as soon as I read LabRat's post I had a 'doh" moment. Of course that is the solution and I have some here somewhere from when I did the bathroom window.

Jon

[mschell]

As FYI, I have built several stars out of coro with 5 of the 3 LED modules. They look quite bright and from any distance beyond 5 ft, the ribs don't really show.

Now, if your tree is made up of mini's, the star won't be as bright....

The front of the coro is about 2-3 inches above the back side. and there are coro sides as well.

I'm not sure that unless you have totally clear, but translucent plastic on the front that it will be any brighter than with white coro...

[jpb]

Thankyou to all. Once I had a proper try with the corro I have built an awesome looking 6" star.

When I showed my wife her initial comment was "that's pretty, where did you buy that?" You can't get higher praise than that can you.

Jon

[LabRat]

Pictures????

[jpb]

Here are some pictures of the finished star. It is about 6" tall and sits on top of a 6' spiral rope light tree. I have removed the rope lights and replaced them with RGB pixels.
The star has 9 RGB non pixel LEDs and is being controlled by a DC SSR at the base of the tree as there was no room inside the star to mount an SSR. With the star being only 6" I could not get the nose of the glue gun into all the corners but I think it is robust enough. This is actually my second attempt as while the first one looked great at night it was a bit dodgy in the daylight. With the Mk2 version I was able to avoid all the mistakes I made in the first one.

The first two photos are of obviously of the panel that holds the LEDs, the holes for the LEDs were cut with a wad punch. To assemble the star I glued the top and side sides to the front panel leaving the bottom panel off. I then inserted the panel holding the LEDS and tacked it in place with the glue gun. I then carefully slid the bottom panel up over the mounting pole, ran a bead of glue on the edge and stuck it to the front. Then glue the back on and fired it up.

11605116061160711604

Jon

[dirknerkle]

Well done! Good craftsmanship, use of materials, and a really nice effect! You might write up a step-by-step how-to with photos and add it to the Wiki in the display construction section. Maybe include some dimensions, perhaps a template for the star and the pieces needed, etc. The concept could likely be easily adapted to other shapes as well, but you made a very clean-looking topper!

[dmoore]

Here is one we produced:


http://vimeo.com/29922631

[fasteddy]

Part of the issue why your brightness might not be as high as you would hope is the use of the correct light. The lights you are using have a very wide beam so not all the light is directed to the face of the coro. The best lights to use with coro for background lighting is either the 5050 RGB modules or the 5050 strip, these LEDs only direct the light 1 way and thus give a higher level of light on the surface of the star

[DennyMo]

I'd be very interested in seeing video of your tree in action, do you have any posted on your linked youtube page?

[MacabreRob]

Wow! Nice. Those are some big a** LEDs...

[dmoore]

I'd be very interested in seeing video of your tree in action, do you have any posted on your linked youtube page?

The star above is shown on the tree in this video on the bottom left:


http://vimeo.com/18220911

[jpb]

Hi, I have put three short clips on my You Tube page http://au.youtube.com/user/JabiruLights of the tree and star. Sorry about the focus (or lack of).

Jon

[DennyMo]

Hi, I have put three short clips on my You Tube page http://au.youtube.com/user/JabiruLights of the tree and star. Sorry about the focus (or lack of).

Jon
Thanks for these. In the videos, it looks like the colors on the "slow fade" are rather pastel, while the "random" are more vibrant. Is that the case, or is that just a camera "artifact"?

Also, which LED nodes did you use for your trees?

[Livermore-Dad]

The star above is shown on the tree in this video on the bottom left:


http://vimeo.com/18220911

Dmoore talk to me about your pillars, are they all 5050 strips or? Amazing how clean the lines are and how bright. Makes it look like the pillars themselves are the lights

Thanks
Tory

[jpb]

Thanks for these. In the videos, it looks like the colors on the "slow fade" are rather pastel, while the "random" are more vibrant. Is that the case, or is that just a camera "artifact"?

Also, which LED nodes did you use for your trees?

In the slow fade I was trying to get a slow transition between the colours and yes it has ended fairly pastel. The song that is behind it is Silent Night so the pastels kind of suit but if I get time I will possibly redo that bit and go for more solid colours. There is plenty of brightness in them when doing the solid colours.

The pixels are WS2801 from Ray Wu http://www.aliexpress.com/fm-store/701799/209889132-320389559/12mm-8mm-led-pixel-RGB-led-channel-lettet-waterproof-WS2801IC-256-level-gray-scale-DC5V-input.html
That is one universe being driven by one of RPM's USB-DMX interfaces into a Pixel driver also from Ray Wu http://www.aliexpress.com/fm-store/701799/209915969-440556828/Mini-protocol-Decoder-DMX-to-WS2801-512-dmx-address-decoded.html. They are being powered by an ATX power supply

Jon

[dmoore]

Dmoore talk to me about your pillars, are they all 5050 strips or? Amazing how clean the lines are and how bright. Makes it look like the pillars themselves are the lights

Thanks
Tory

Tory

They are 6803 pixel strip inside a coro diffuser. Here is a video that shows it in detail:


http://vimeo.com/16366467

It shows the value of a diffuser to "expand" and distribute the light from a limited number of (expensive) pixels.

[griffixdc]

wow the work money and engineering to do this is amazing wish i could be involved with this :) awesome video and explanation

[WireWrap]

wow the work money and engineering to do this is amazing wish i could be involved with this :) awesome video and explanation

I regret to inform you that you have contracted CLAP (Christmas Light Addiction Problem) and you are already involved. :mrgreen:

Please take the time to advise your family that you will henceforth be unavailable for any coherent conversation for extreme periods of time, and that your children's college funds and inheritances have been re-allocated to Blinky-Flashy. ;-) :roll:




:D

[dmoore]

wow the work money and engineering to do this is amazing wish i could be involved with this :) awesome video and explanation

Here is a behind the scenes video:

http://vimeo.com/18221711

Of course be sure to watch our RGB Video Basics Course:

http://www.holidaycoro.com/kb_results.asp?ID=15