UV filter in Toronto? Home Depot???

[tetutigre]

Hi,

I know halogen are less efficient than MH, but I don't have $200 for a HQI set, and MH are a lot bigger than halogen. And I've seen some projector use this, so I thought I'd give it a try. Besides, I don't want to fry this 2.5'' lcd with a MH,,, with anything after all !! I wanna have the lcd for years to come (if possible), and I know that UV and Ir are real problems that MUST be avoided... so do you think with the lexan and the cold mirror I'll be good to go? would a heat glass/mirror work for this mini setup??

Thanks for your help. You da man !!!

And thank you too ancorp ! I wish I knew as much as you did at your age... cheers !

[ancorp]

Tetutigre, thanks for the kind words, lol

I too em planning to use lexan and a cold mirror with a 2.5 (or 2.6?) inch lcd, and I will use a 500 watt halogen work light (8.99 CAD at canadian tire, 3.99 CAD for 2 replacement bulbs!)

Damn its hot!!!
Im going to use one or two computer fams along with the lexan and cold mirror (if I get one that is)

Good luck!

[tetutigre]

Yeah, you WILL need those fans with that light.... I was doing some testing with a cracked LCD and a 50w dichroic, and I started getting a black spot on the LCD within a minute or less... later I put a fan on top of the LCD blowing air towards it and it held on longer...

Now imagine 500w !!! Yikes!

Good luck to you !!! Keep me posted !!

And BTW, I've been using my lenticular screen more, and am starting to really love it !!

[Guy Grotke]

I think 500 Watts is a bit too much. If a 50 Watt halogen bulb overheated an LCD, then a 500 Watt halogen bulb with a 90% efficient cold mirror would also overheat the LCD. Halogen bulbs really do put out a lot of heat. A lot of it is long wave-length IR that you could stop with a piece of low-E glass. Maybe with that and some careful attention to the air flow you can keep enough heat away from the LCD. Make sure the air flow travels from the LCD compartment toward the lamp compartment, so you are not sending forced-air heat to your LCD!

By all means, get a cold mirror. I have one from surplusshed.com ($5 US) and it works great in all my tests.

[ancorp]

hmm... great another glass...

where can I get a low-e glass in Toronto? Home depot too...?
I hope...

[Guy Grotke]

Home depot certainly sells complete windows with low Emissivity glass. I don't know if they sell individual glass panes made from low E glass. You could ask them. The windows consist of glass with a special long wave IR blocking filter, with an argon-filled space between double or triple glazing. They keep the heat in your house during the winter, so I am sure they would have them in Canada.

If Home Depot doesn't sell it by the piece, then you should call a few glass shops. They should be able to cut any size you want and grind the edges for you so it is easy to handle. Glass is very cheap. But maybe you should just try using a cold mirror to see if that is enough. Maybe you won't need any more heat control filtering.

[ancorp]

Great, thanks a lot Guy Grotke!!!

[projectile]

hmmm is hqi so costly??? i got phillips (mhn-td) (uv block)150 w for eqivalent of around 30 usd replacement is around 10 usd ....strange!!!
this thing with a 60 mm dia and 60mm fl condenser along with a spherical gives out so much light that it fades out my psone screen set to least brightness...and heat is very very less i am using two comp fans...the white coloured light is a very good thing search around a bit and and definatly go for it if it fits your budget ....or i will send it to ya bud

btw guy grotke is lexan mr10 as eff cause the guy who sell it has zero knowledge about the specs and since it is cut to pieces its really hard to make out anything written on the stickers too.

[tetutigre]

Do you have the specs for that bulb? what about the ballast and stuff?

[Guy Grotke]

I don't know. I looked at some papers at:

http://www.geplastics.com/resins/tec...chnifacts.html

but I did not see anything showing the absorbtion of UV for different varieties of Lexan. I did read one paper about UV surface degradation of lexan, which suggests that it does absorb a lot of the UV (otherwise it would not just occur at the surface). The Lexan XL has a special surface coating on one side that will make it more resistant to this UV degradation. I think without this coating it will still absorb as much UV, but it may become yellow over time. So you could just inspect it evry month or so to see if you need to replace it.

By the way, I tried cutting some of the 0.093" Lexan sheet using glass cutting technique: It was too flexible. Then I tried a fine metal cutting blade in a jigsaw. That worked perfectly. I got a very smooth edge with no cracks.