VG248QE Backlight, is it that bad or i'v got a defected one?

[tigerman]

Hi everyone, i've got the Asus VG248QE yesterday.
The Backlight totally changes depending if you are at plain 60hz or with an higher refresh rate.

Even without the lightboost at 121Hz i can see a bit of white stripes going diagonally and the light is very bad distributed over the panel i have 3 big horizontal light lines (like 3 neons) and those horrible white strips all around the monitor (expecially the bottom side).

At 144hz the problem is more pronunced, and at 120Hz with Lightboost or 3D the problem is huge i can see those clearly and really disturb anything i'm doing i can see that in game or watching dark videos/movies.

I've tried maxing contrast and brightness on all various "splendid" setting but the problem doesn't exists at all at 60Hz and the light is much better distributed.

Photos with black background

120hz with lightboost


60hz


as you can see at 60hz there are no white stripes and the light is much better distributed over the panel (it's very bright because of my camera setting)
at 120hz you can see those horrible whit strips and the 3 horizontal light bars...

does anyone with the same model can have a look so i can understand if i have to return it or not.
thanks

[Chief Blur Buster]

There are two behaviors being described -- one normal, and one not normal.
Most of the differences I see, are actually black field nonuniformities that change to refresh rate and strobe mode.

Not normal
The diagonal lines is unusual/weird, and I don't get them on any of my monitors. There MIGHT be some edgelight bleed, but it can also be gamma/black nonunformities too, considering the bleed-looking artifact appears to disappear from the 120Hz LightBoost image. Make sure the panel is fully warmed up, since tension on an LCD on a newly arrived monitor, especially cold, can amplify the black nonunformities. After a while, it balances out. But if you've had this for a while now, and the 60Hz remains as bad as currently, it might be worth considering claiming warranty, especially since you're getting diagonal lines (when I zoom some of these images). Try a different cable, just in case. But the diagonal white lines are definitely indicative of something wrong (defect, cable, etc) and needs to be troubleshooted, and if it's the monitor causing those diagonal white lines, claim a warranty.

Normal
The horizontal bands that show up during a black screen in LightBoost is normal. It's likely caused by different pixel freshnesses prior to strobe, and/or the Y-axis-compensated overdrive algorithms that appears to exist in LightBoost. See related thread http://forums.blurbusters.com/viewtopic.php?f=4&t=178 .... LightBoost monitors have at least faint horizontal bands in blacks due to this, though in real life, it shouldn't look as obnoxious as a long-exposure camera photo. Such band artifacts are normal for LightBoost, as the LCD panel is pushed to limits with strobe backlights, and LightBoost is the first good strobe backlight that successfully achieves CRT fast-motion sharpness on LCD for computers.

[tigerman]

Thanks, i can live with the horizontal bands, but those white stripes are just horrible and i'm happy to hear that is NOT normal, i've got this monitor used and it has already over 700 hours of "power on time", i will call asus and ask for a repair/rma.

thanks for clarification

[nimbulan]

That has got to be a manufacturing defect. My VG248QE has a very uniform backlight, much better than any of my previous displays.

[tigerman]

The backlight doesn't excite me expecially at 120/144hz and in 3d/lightboost, while at 60hz is quite good.
I ask myself why there is no way to set up the backlight power, i'm always on a very dark room and i don't need so much light neither on 144hz and when i'm in 3d, i would like to be able to set the backlight to a lower value to get rid (or substancially reduce) of those bars at the price of less brightness.
I've tried also going on the service menu but i don't know what are those values for but i highly doubt there is a way to reduce that expecially when it's locked by lightboost.
By the way the really "defected" thing on this model are those diagonal white strips, i've called asus today explaining the problem and they will RMA with a new one, nice, considering that i've bought it used for 150€ and i'm going to get a new one.
I'll update here once i get it
I hope the new one will have also a better backlight at higher hz/3d, would be great.

About lightboost, hey the blur is almost gone (and with the glasses is even less, 3d gaming is the smoothest thing i've ever seen from an lcd in my life), but in some cases is not a good thing because now i see some things that i didn't notice without lightboost, for example in cod:ghosts when i strafe i can see very subtle micro-stutters (fps is locked at 90 and cannot be changed), i mean it looks smoother with the blur (no lightboost).
Also i can clearly see now when the mouse is not smoothed in games, even if i have a 1000hz sampling rate if it's not smoothed it's not that good and the result is worst that with the blur (this remembers me when i was playng quake 3 on a crt and i needed the command m_filter=1, something that i didn't take care anymore till today).

Wonder Boy on Mame rocks now, and rocks even more with the glasses on.

So basically lightboost is a nice thing, but it works perfectly only on some games while on others i fell i'm better without it.
more tests coming...

Lastly, another thing i've noticed, with this monitor if i set 3dvision to stay "always" on it keeps the lightboost but the emitter doesn't stay on all the time, even with the registry hack the emitter is off on the desktop and it turns off in game when i press ctrl-t.
with the older samsung 2233rz when i set to "always" on nvidia ctrl panel the emitter always send the signal allowing me to wear the glasses to smooth everything i see (with the price of seeing alternate frames with each eye obviously), now i have to keep opened a 3d image on my browser in order to let the emitter stay always on (and it works also in games once i've pressed ctrl-t).

[Chief Blur Buster]

Good to know you'll get a new one that replaces the one with the diagonal lines; that definitely is something I've never seen before so it must be a defect. Gives you a new draw in the panel lottery, so you may actually get a better specimen this time around for other artifacts too (but no guarantee, and not always covered by warranty).

Meanwhile, have you tried this registry tweak?
www.blurbusters.com/files/ForceLightBoostWithoutGlasses.reg

(Step 12 of LightBoost HOWTO, emitter method).

[tigerman]

yes it works for the monitor but not for the emitter, the emitter turns off when there is no 3d content, with my older monitor i didn't need that tweak and my emitter was always on if i put "always" as option on nvidiacp.

[tigerman]

i've received a new one, sad thing this is worst than the previous one, i have a lot of white horizontal lines all around the monitor and i can see those even at 60hz, that's so bad, i'll call Asus again tomorrow and let's see what they say, what's the point af doing an rma if they change it with another defected one? is their quality control so bad ?

60hz with grey background


120hz+lightboost grey background

[tigerman]

ok third monitor arrived, this time i have only 1 horizontal (instead of dozens) line on the upper side of the monitor, clearly visible in lightboost mode.
So again the monitor is not perfect, by the way, i'm bored of rma and wait all the times, i'll stay with this one, i can live with that line.
I think this one is new, i checked the service menu it has only 64hours of power on and it still have the big sticker on the upper right side.
The previous one had 300+ hours.
Time to use this lightboost finally!!!

[Chief Blur Buster]

Glad to know that the third time is the charm.