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able to see red,green,blue lights on my proj. TV

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#1 of 6 OFFLINE   shaneT



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Posted November 14 2003 - 10:32 AM

I have a 60" phillips projection HDTV. It is approximately 2.5 years old
When I stand close to the TV, and look down at it, I am able to clearly see glow of the red, green and blue lamps through the screen
(or maybe red green yellow, cant remember, sorry). Is this I went to the Best Buy and didn't notice this happen on any of their display TV's.

Also, and seperately, contrasting colors, such as white credits on black background, or bright reds have very very noticable amounts of glow around them. So much that a bright white box in the top quarter will lighten the black of the entire rest of the screen. I set up my TV with the original copy of video essentials.

Are these problems just a sign of a cheap tv or is there soemthing I can do to change this. The visibility of the lamps doesn't bother me as much as the color bleeding does.

hit my car, everyone else does

#2 of 6 OFFLINE   ChrisWiggles



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Posted November 14 2003 - 02:02 PM

Sounds like you could do for some lense tweaking (striping, perhaps lining), and some interior lining of the RPTV to suck up the bleed from the projector lenses, etc.

I'm rushing out the door, do some searches here, and also read up over at keohi hdtv, tons of good RPTV info written up there.

#3 of 6 OFFLINE   Allan Jayne

Allan Jayne


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Posted November 19 2003 - 12:20 AM

The red, green, and blue "lamps" should not be visible from a normal viewing position.

A common shortcoming of rear projection TV sets is that the interior of the "box" is a bit shiny causing dark areas of the screen to light up when there is bright subject matter. Purists have often opened up the TV and lined the interior with black velvet, or (less expensive) Duvetyne® fabric. While you are at it, you should also cover other shiny objects inside but be careful not to obstruct openings needed for ventilation and heat dissipation.

Don't be disappointed if your efforts are not perfect. Even in a movie theater, the dark areas of the screen will lighten up a bit during bright scenes from light reflecting about the room.

Video hints:

#4 of 6 OFFLINE   shaneT



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Posted November 19 2003 - 02:23 AM

Allan and Chris,
Thank you for your links and advice. They were exactly what I was looking for. The velvet seems like a good tip. Have you tried it?
hit my car, everyone else does

#5 of 6 OFFLINE   ChrisWiggles



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Posted November 19 2003 - 05:51 AM

There is also the issue of lense flare, which can be reduced by using liquid-couple projectors. obviously this isn't something you can do to your TV without buying a new one. No i haven't lined my TV with black fabric, because i don't have an RPTV (front-projection). IT's not set up yet either, but i guess you could say that i will, if you consider the interior of the entire room as similar to the inside of the TV, and I will have dark walls, especially near the screen, for similar reasons.

#6 of 6 OFFLINE   Greg_R



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Posted November 19 2003 - 08:58 AM

Avoid the velvet (very $$$) and go with Duvetyne cloth and tape (available at theater supply houses). Here are a few easy upgrades that will make major improvements in your picture (total cost <$100):

- Disable SVM. This usually involves removing a plug inside the PJ... read the keohi HDTV page for more info.
- Building a duvetyne covered shadow box over the lenses (do not block the lense->mirror path). This will eliminate the problem you are having when you stare down at the guns.
- Line the interior with duvetyne cloth. This will greatly reduce reflections inside the RPTV cabinet.
- Remove the protective plastic screen over the fresnel lense. This is fine if you don't have kids. If you think someone may scratch the screen, keep the protective cover on!
- Clean the CRT lenses if they are dirty (be careful not to scratch them!)
- Build custom masks for each aspect ratio out of black construction paper. You'll notice that the borders on letterboxed material is grey rather than black. By creating a custom mask (that hangs over the front of the TV) you will give your eye a better reference to absolute black. This results in higher perceived contrast ratio (and thus better picture).
- Keep in mind that you'll need to touch up your setup (with VE) and convergence every once in awhile.