Question: Consistency of backlight in LCD monitor

  • Thread starter Thread starter DW
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DW

Greetings, all:

I just bought a Hyundai L90D+. I'm pleased with it overall (no bad
pixels, good refresh, vibrant color), but have one question:

The backlighting is not 100% uniform. I've read the blurb about this
display on Tom's Hardware, and recognize that I can't expect perfect
uniformity, especially around the edges. In games, it's completely
un-noticeable. The only situation I can see any difference is when I
have a white Windows screen, and even then the difference is so subtle
I have to really stare at it to make sure I'm not fooling myself. But
the truth is, the right third of the screen is maybe 1 or 2% brighter
than the rest of it.

I'm almost convinced that this is not worth getting in a twist over; I
doubt I'll get anything better if I do decide to fire it back for an
exchange (and even then, I'll have to pay shipping and restocking to
TigerDirect).

Any other viewpoints out there?

Thanks!

DW
 
DW said:
Greetings, all:

I just bought a Hyundai L90D+. I'm pleased with it overall (no bad
pixels, good refresh, vibrant color), but have one question:

The backlighting is not 100% uniform. I've read the blurb about this
display on Tom's Hardware, and recognize that I can't expect perfect
uniformity, especially around the edges. In games, it's completely
un-noticeable. The only situation I can see any difference is when I
have a white Windows screen, and even then the difference is so subtle
I have to really stare at it to make sure I'm not fooling myself. But
the truth is, the right third of the screen is maybe 1 or 2% brighter
than the rest of it.

I'm almost convinced that this is not worth getting in a twist over; I
doubt I'll get anything better if I do decide to fire it back for an
exchange (and even then, I'll have to pay shipping and restocking to
TigerDirect).

Any other viewpoints out there?

Thanks!

DW
Click to expand...
Heh ... You'd probably be *really* surprised if you actually measured it!
Actually if the difference is "smooth and monotonic", our eyes can NOT
distinguish a difference of 40%. This was well documented & specified in
CRT display technology, and has pretty well been translated into the LCD
technology as well. Recent tendencies have been to try and reduce that
uniformity spec in LCDs to less than 30%, but it is actually an exercise in
futility, IMHO. In order to meet tighter specs, the cost HAS to go up, and
that's counterproductive to increasing market penetration.

I think it is indeed not worth getting into a twist over - you may be hard
pressed to find a more acceptable unit at an acceptable cost anyway.

Rgds,
NGA
 
Interesting. Well then, I guess the difference must be just a hair over
40%.

I consider it kind of like shadow mask wires. At first, you do notice
it; but after only a short time you totally forget about it.
 
DW said:
Interesting. Well then, I guess the difference must be just a hair over
40%.

I consider it kind of like shadow mask wires. At first, you do notice
it; but after only a short time you totally forget about it.
Click to expand...
Well, if it's more like the shadow mask wires, it could be much less
and be visible, because its not a gradual change, but more of an
abrupt one, as are the shadow mask wires.
Anyway, if you find you can live with it, that's probably the best
solution.

Regards,
NGA
 
Weird. I ran a little app called 'Dead Pixel Buddy', which gives you
solid screens of white, black, red, blue... just to look for bad
pixels.

When it's the solid screen, it all looks very consistent.

But then I opened a large Notepad screen, put some text right in the
middle of it, and moved that text around the screen. As I followed the
text, I saw a lot more variation in brightness.

Funny what your brain decides to do with this stuff.
 
DW said:
Weird. I ran a little app called 'Dead Pixel Buddy', which gives you
solid screens of white, black, red, blue... just to look for bad
pixels.

When it's the solid screen, it all looks very consistent.

But then I opened a large Notepad screen, put some text right in the
middle of it, and moved that text around the screen. As I followed the
text, I saw a lot more variation in brightness.

Funny what your brain decides to do with this stuff.
Click to expand...
OK - now with this data it sounds like you are seeing what we call
scaling artifacts - it sounds like you are not running the panel at its
native format, so your data has to be "scaled" to fill the entire pixel
map of the panel.
I'm not familiar with the Hyundai L90D+, but if it's a 19", it should
be a 1280 by 1024 format, so you should set your desktop format for
the same to avoid these artifacts.

HTH,
NGA
 
Oh, it's not an artifacting issue; I don't mean the brightness or
clarity of the font itself; but if I follow a bit of text on a white
screen as I move it around the screen I can see more clearly if the
background brightness is not totally uniform.

I am running at 1280.

Anyhoo; it's not a big effect, so I think I'll just adjust. ;)
 
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