[simp1yamazn]

need help finding a source for hot mirrors. doesn't have to be big, like 5x5ish? been lookin around the web and haven't come up with much.

[pujs85]

what exactly hot mirror is?
is it another term of tempered glass or polycarbonate sheets?

[simp1yamazn]

nope. a hot mirror is a mirror that only reflects infrared light and UV light but allows visible light to pass through. if you use a hot mirror you don't need the polycarbonate sheet, tempered glass, and probably no cooling needed for the LCD or lenses. however, they are much more expensive than lexan and tempered glass

This post has been edited by simp1yamazn: 03 June 2007 - 02:58 AM

[pujs85]

simp1yamazn, on Jun 3 2007, 02:58 AM, said:

nope. a hot mirror is a mirror that only reflects infrared light and UV light but allows visible light to pass through. if you use a hot mirror you don't need the polycarbonate sheet, tempered glass, and probably no cooling needed for the LCD or lenses. however, they are much more expensive than lexan and tempered glass

cool, how much it would cost for hot mirror , say for 15 inchi panel?

[tgreenwood]

simp1yamazn, on Jun 2 2007, 09:03 PM, said:

need help finding a source for hot mirrors. doesn't have to be big, like 5x5ish? been lookin around the web and haven't come up with much.

The only decently priced source I have found is the B&H PhotoVideo website. They have a variety of sizes of hot mirrors, one close to the size you specified is $57.50 here.....Rosco Permacolor Glass Filter - Hot Mirror - 5-1/4" Round.
You can sometimes get lucky at surplusshed.com and find a hot mirror available there.
Another option is Rosco Thermashield. From the website : "Specially coated film reflects infrared energy to extend the life of color in super hot lighting fixtures. Thermashield is an optical grade polyester film, finished on one side with a proprietary vacuum-deposited multi-layer coating. Set in the beam of a lighting instrument, it will reflect back infra-red energy, effectively reducing the transmitted heat, while transmitting 80% of the visible light."
And a 12 x 12 sheet is $24.95 here.....Rosco Thermashield - 12x12"

Don't let the "80% transmittance" throw you, a lexan sheet that a lot of people use for a heatshield is only 90% transmittance, and the thermashield really blocks the heat.

Tgreenwood

[bknight]

i got a old lamp post light. in it was a glass that was painted black
was it just for reflecting light ???

[jasle]

tgreenwood, on Jun 2 2007, 10:07 PM, said:

The only decently priced source I have found is the B&H PhotoVideo website. They have a variety of sizes of hot mirrors, one close to the size you specified is $57.50 here.....Rosco Permacolor Glass Filter - Hot Mirror - 5-1/4" Round.
You can sometimes get lucky at surplusshed.com and find a hot mirror available there.
Another option is Rosco Thermashield. From the website : "Specially coated film reflects infrared energy to extend the life of color in super hot lighting fixtures. Thermashield is an optical grade polyester film, finished on one side with a proprietary vacuum-deposited multi-layer coating. Set in the beam of a lighting instrument, it will reflect back infra-red energy, effectively reducing the transmitted heat, while transmitting 80% of the visible light."
And a 12 x 12 sheet is $24.95 here.....Rosco Thermashield - 12x12"

Don't let the "80% transmittance" throw you, a lexan sheet that a lot of people use for a heatshield is only 90% transmittance, and the thermashield really blocks the heat.

Tgreenwood

Has anyone tried this "Thermashield?". Does it work well? How close can you put it to the bulb?

[Rion]

American science and surplus.

heat mirror.

www.sciplus.com

they're something like 10 bucks for a 6 inch square. if you're thinking of tossing it in front of the bulb, go for it... keep it a good three or four inches away, and hit it with a fan blast on the hot side if you can - all glass is an IR absorber, it's a specialized coating that gives you the IR reflectivity. The other thing to keep in mind with this stuff is that the light that hits the LCD is still light (always light, really...) but when it passes through the LCD, it excites the LCD material itself - glass, crystals, circuitry, etc... and generates heat as its absorbed.

heat mirror won't fix that. ;-)

yargh.

my question is this... anyone try to take a crapped-out LCD/DLP commercial unit and drop in a non @$$-spensive bulb into it?

BKNIGHT:: Your old lamppost was likely painted black on the top half of the light. Or to block out light on one side. During WWII (I have a 1939 buick) car headlights, street lights, and various other lighting fixtures that were visible along coasts (here in VA, etc.) were blacked out or half-blacked so that cities, bridges, and other infrastructure couldn't be targeted by German U-Boats.

Black paint will only absorb light - won't really reflect anything.

This post has been edited by Rion: 04 June 2007 - 11:45 PM

[sensibull]

Rion, on Jun 4 2007, 07:38 PM, said:

they're something like 10 bucks for a 6 inch square.

If you can find a true hot mirror, 6 inches square for $10 please share a link. Nothing like that at sciplus and I'm doubtful anywhere else for that matter. Unless you can find a seller on ebay who doesn't really know what they have, hot mirrors of that size will be considerably more expensive.

[Koala]

Rion, on Jun 4 2007, 11:38 PM, said:

my question is this... anyone try to take a crapped-out LCD/DLP commercial unit and drop in a non @$$-spensive bulb into it?

Hmm, never saw anyone in this forum, but in severall European forums there are a lot of posts about this.

The german DIY-community has a whole section on Kaufbeamer Modding (Questions concerning how to modify commercial projector) and results of such mods .
You can use Babelfish or Google to translate these pages.

To fit another lamp in a commercial projector you need to modify the electronic (shortwire the lamp sensors, otherwise no picture will be projected), if you don't use the internal ballast. This kind of modding is usually done with topspot bulb oder 50W Xenon bulbs. Especially for DLP projectors you need short-arc lamps. The original reflector is also required (only the bulb itself is replaced).

Greetings,
Matthias

This post has been edited by Koala: 05 June 2007 - 06:01 PM