I tried posting this in the ref and tut section but i aint got the privelidges yet

This has been touched on before, but this particular didnt come up when i searched the LL forums..I personally think it could be of major importance.

I know all too well about this as im trying to fix a terrible issue myself..

this guy shows how he reduced the backlight bleed dranatically on his stock panel..



The fix

It is also very apparent that some TFTs are worse culprits than others in this respect, Dell being one of the worst offenders. Its also discouraging to hear that the problem can increase over time

Im not scaremongering here, please don't get me wrong. but i feel that this is a real important issue, and along with response time and contrast ratio, there out to be a backlight bleed level....after all, if a flourescent backllight can reveal it, think what 400w of light will do...

heres what i'm suffering at the moment
Referred to across the web as the "X phenomenon"

Click to view attachment

This is in response to your post on the old thread here http://www.lumenlab.com/forums/index.php?s...ndpost&p=135653

I checked out the link you sent on the forum. This makes sense to me because I noticed that after I put electrical tape over my edge connectors and the very bottom "clear" area of my LCD (my LCD is not framed it is sitting on wood blocks in my sled which was a design i copied from another PLOG) That the problem is now only present in the bottom of my projection (the top of the projector) because I have eliminated 100% light passing through the top of the projection (bottom of the box)

The top of my LCD also has light going it because that is where my air flows through.

I covered the top of the LCD with electrical tape as well but its not flush because of said air flow. This makes me want to use a piece of cardboard or something in front of the LCD as this bootleg drawing illustrates to block the light

Oh I wanted to add that after i put the electrical tap across the top of my LCD the problem was definately reduced

I too had the "X phenomenon" on my 15" build. It's also present on my current 17" pro build, but to a much lesser extent.

It's my theory that this is due to internal reflections in the LCD panel itself. I tried various things to reduce or eliminate it, but without success.

My concern with elecrician's tape is that it's highly susceptible to melting with high temperatuires, and the adesive residue is nasty stuff. High temperature silicone tape would be a much better choice, though far more expensive.

@ladieu:

This is a bit off-topic, but I'll make a suggestion for you. Add the cardboard perpendicular to the LCD at the top. This will help keep the light from passing by the LCD, and still allow airflow, something like this:
Click to view attachment

Thanks for the heads up on the tape. I will replace this asap

Possible breakthrough on the backlight bleed on post #52 here.. I know Ladieu has already seen it, but this might help others who have the same problem.