[Miles]

I saw one posting with reference to a "Halo" and wondering if this is something I'm experiencing. I have 100" 4:3 Draper. There is about a 2" black border around the matte white surface of the screen. I'm using a HTPC to play DVD/satellite material. When I set the LT-150 on my coffee table and center the 4:3 image in the matte-white area and watch a movie, there still seems to be a large grey area around the the screen which lights up the light-coloured wall behind the screen. Is this normal or am I somehow not using the entire 1024x768 DLP panel. I am using a 1024x768 desktop resolution and connecting via the supplied VGA cable. One note. I have noticed a pin on one end which has been bent so that it won't make contact.


I really would like to know if this is normal...


Thanks for any help,


Miles

 

[derazmus]

I don't think that's what people mean by "halo". With respect to the LT150, it is the ring of leaked (non-image) light that appears some distance from the bottom (or top in the case of table mounting) of the image. In my case, with the LT150 mounted on the ceiling projecting an 80"x60" image, I see the halo about two feet below the screen and it curves around and up a bit to the left side. Should be able to get rid of it with some black construction paper near the lens.


The lighter gray border around the image is normal. It's about 4 inches wide all around in my setup. When I buy a screen, I'll just have to make sure the masking border around the screen is at least that wide, or else add more material myself.


There is one other use of "halo" that I'm aware of and it has to do with image sharpening filters (I think). Do a search. There was a recent article on it around here somewhere.



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Dave E.

 

[Frode]

Watchformore has the right of it. Halo is the grayish area around the projected image. It's because the real chip resolution is something like 1100x800 and so only part of the chip is used (1024x768). You can tell by standing real close to the screen and looking at the halo. You'll notice grayish pixels and a screendoor. Light spill on the other hand is when you have light areas around that again, but these are somewhat diffuse and is not halo.


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/frode

 

[benjdm]

So why isn't the whole panel used ?

 

[watchformore]

I always assumed that the light border area around the display area was what people were referring to as the 'halo'.


I also get the arc of light further above the display area with my table mounted LT150. I thought this was what people were referring to as 'light spill'.


Anyone want to create a dictionary for us?


-- Greg

 

[Miles]

Great answer Frode... I wonder why they didn't make the panel a standard computer resolution in the first place? Strange.


Miles

 

[Frode]

My guess is that the reason they don't use the whole panel is a yield issue. If there's a dead pixel at the edges of the chip they can just shift the image slightly and move the used part to an area where there is no dead pixel.


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/frode