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Light diffusion

Started by dustyfro, Aug 30, 2009, 03:38 am

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dustyfro

Aug 30, 2009, 03:38 am Last Edit: Mar 24, 2010, 09:15 am by Scarfwearer
I put a fluorescent light bulb inside the lamp that I made out of a peanut butter jar, and was BLINDED!  It's in my living room, so I was hoping that it would turn out a little softer, but with nothing to difuse it, it's really harsh on the eyes.

So what I'm looking for now is something to put on the inside of the jar to diffuse the light a bit, but it has to be a little heat resistant.  Would etching stuff work?  Any other suggestions?
x Hannah

the_temporal_mechanic

Sep 01, 2009, 02:36 am #1 Last Edit: Jan 21, 2010, 10:32 am by scarfwearer
Parchment is only good to about 400 degrees, and browns over time as it "dries" out.  I like the idea you had for etching stuff.

dustyfro

I bought some etching cream at a craft store to etch glasses and I'm going to see if it will work on the inside of my jar once I figure out how long it's supposed to stay on.
x Hannah

deck5

Aug 30, 2009, 04:16 am #3 Last Edit: Mar 24, 2010, 09:12 am by scarfwearer
Have you considered a way smaller light bulb?

Teletran

Aug 30, 2009, 08:49 am #4 Last Edit: Mar 24, 2010, 09:13 am by scarfwearer
If using a compact fluorescent bulb the brightness is roughly equivalent to surface area, they usually have a diagram detailing their equivalence to incandescent bulbs i.e. brightness. Fluorescent bulbs put out less heat than incandescents but you'll need to get one rated for an enclosed housing. A low output bulb shouldn't put out much waste heat so if you have say a 2.5" (65mm) spiral in a 4" (100mm) enclosure I wouldn't predict any problems even if you line the glass with printer paper to cut down the light. If on the other hand you have a bit of a tight fit you might run into some problems. I'd recommend a tubular coil bulb which would A. output less light. B. generate less heat and C. is smaller and less likely to contact the sides of the enclosure and/or the diffusion material. Or you could go down the LED trail because they're smaller produce practically no heat and will last the lifetime of your box. I think that's what timegirl did so you might want to ask her about the practical aspects. If it's just diffusion you want I'd recommend a white or frosted plastic a few millimetres thick so it doesn't melt or maybe the printer paper thing in the short term just keep it away from the bulb.
(http://img194.imageshack.us/img194/1360/omni02g.jpg)

Teletran

Aug 30, 2009, 08:50 am #5 Last Edit: Mar 24, 2010, 09:13 am by scarfwearer
Sorry I didn't mean to write you an essay.
(http://img194.imageshack.us/img194/1360/omni02g.jpg)

dustyfro

Aug 31, 2009, 04:32 am #6 Last Edit: Mar 24, 2010, 09:13 am by scarfwearer
The bulb is a coil, 13w equivilant for a 60w incandescent.  The fixture makes the bulb stick up unusually high, otherwise I'd probably just swap out the lamp I made for a newnew/old series fesnel, which is currently too short.  I'll maybe leave the light on for a while and see how hot it gets.
x Hannah

dematerialiser

Aug 31, 2009, 07:40 am #7 Last Edit: Mar 24, 2010, 09:14 am by scarfwearer
You could do some searches for 'scrim' - material used to diffuse and lessen light for stage and tv, most of them are heat resistant as they're designed to be fixed to the front of lights while they're on. That should do the trick - and I bet you can request a free sample/offcut which is big enough for your light.

cheers
Chris

deck5

Aug 31, 2009, 03:36 pm #8 Last Edit: Mar 24, 2010, 09:14 am by scarfwearer
Quote from: dematerialiser on Aug 31, 2009, 07:40 amYou could do some searches for 'scrim' - material used to diffuse and lessen light for stage and tv, most of them are heat resistant as they're designed to be fixed to the front of lights while they're on. That should do the trick - and I bet you can request a free sample/offcut which is big enough for your light.


True.  Scrim is fine wire mesh.  You might be able to find something suitable at the hardware store; being metal, it should be fine with heat.

dustyfro

Sep 01, 2009, 01:01 am #9 Last Edit: Mar 24, 2010, 09:14 am by scarfwearer
Oh, what about parchment like you can put in the oven?  That should stand up to the heat, yeah?
x Hannah