CMV1515 working with OHP (lots of pics)

[dracul]

This low e glass, when you bought it did you ask them what its normally used for? I am not in the us and need to try to track it down that way.

Also you have the fresnels before the lcd but are you only splitting them. I mean do you have a little distance between the fresnels? IF so how come?

[harmsd]

LOOie,

I have just finished my own OHP + 15" lcd screen setup and it is working great, i will post the results in a seperate thread shortly.

I am currently having the same problem you did by which about 1" of the lcd is cut of on each side because it is wider then the fresnel of the OHP, after doing your fresnel split and making a frame for all three did you get the FULL lcd projected onto the wall, it appears as you did i just wanted to be clear on it.

[dracul]

But this is not an issue for letterboxed movies correct?

[Guy Grotke]

Low emissivity glass lets all the visible light through, but blocks most of the long wavelength IR. But it doesn't block the near-IR. It is used in house windows to prevent the emission of heat (long wave) out the windows during the winter. So sunlight can come in with all the visible light and near IR, get absorbed by walls, floors, etc. Then the longwave IR those objects emit will be reflected back into the house. You can use it in a projector to block longwave IR emitted by hot surfaces around the lamp. It won't help at all to block the heat coming diretly from the lamp. You need a hot mirror for that. Or maybe some V-Cool film.

Plexiglas is a registered trademark for acrylic, like Lexan is for polycarbonate. Both of these absorb UV very well, but that process eventually degrades the material so it turns yellow and foggy. Lexan XL has a special UV blocking coating on one side to prevent the UV from getting to the polycarbonate layer. So it should work better for longer. (Make sure you get the UV coating facing the lamp!) I find Lexan much easier to cut than Plexiglas: I use a fine toothed metal-cutting blade on a jigsaw. Cuts beautifully!

[HiLLBiLLY]

For those that don't have the luxury of power tools ie. jigsaw, dremel or a router to cut the plexi you can use a fine tooth metal blade from a hacksaw to get the job done too :-)

[LOOie]

wow.. people still read this thread? sorry, i havent been on here for almost a year and email hasnt been working for most of that

letterboxed movies have never been an issue for me but i guess everyone's OHP setup is a little different. i'm missing about an half icon's width (about less than 0.5") on both sides, its annoying but i can live with it. brainchild's setup is still the best setup for this sort of thing if you're willing to put in the effort, IMHO.

[BELGOFAC]

Hi Looie,

Great job you did. As you noticed more and more people are jumping on the Home built projector bandwagon because of the high costs of the commercial bulbs. I am one of them. I live in Melbourne, and I got inetersted by spending a lot of time on the Australian Media centre website.

A have a few question though.

Are you using the original light setup of your ohp?
How hard was it to replace the original lenses of the ohp?

Regards,

Belgo

[LOOie]

yep, original light setup, it gets a bit warm though with the halogen.

re: lens, I just unscrewed the fresnel from the bottom and removed it altogther. The top mirror/lens assembly is unchanged.

hmm.. its been almost 2 years since I started this thing. commerical projectors have got a lot cheaper and people's diy techniques have gotten a lot better. the OHP is good and easy for a quick first project but if you're serious about results, check out brainchild's lumenlab site, theres a few few aussies there. or for a free site, check out the results from aussies @ OCAU site here and here.