Dell u2711 Backlight Variation Problem

[tmr2L]

Hello,

I just received a new Dell u2711 monitor yesterday & I feel the monitor is simply too bright. If you don't want to read the entire post, skip to the backlight photo links & let me know if they look normal.

What do I do?
- Programming, almost exclusively.
- I use a dark theme with a black (#000000) background.

Why did I get this model:
- 2560x1440 resolution while avoiding 30". (don't mind the pixel pitch).
- To have plenty of room to layout multiple txt files side by side.

I care about:
- Minimize luminescence, keeping the overall image visually appealing.
- Have black be as black as possible, i.e closest to the state where the monitor is powered off.

I care less about:
- color accuracy
- response time

So what's the problem?
- The monitor is very bright. With brightness at 0 it still feels like I'm looking at gray rather than black.
- There's a gray tone to most of the panel rims, with the bottom right corner being the worst.
- There is noticeable brightness variation, especially near the corners, which is hard to ignore.

So I put together a small experiment: I took a series of 10sec long exposure pictures of the panel at 10% brightneess stops, all the way from 0% to 100% of an all black image. I think contrast is irrelevant but was 50% for all the photos. The picture taken at 10% brightness shows of the variation best (see below).

I'd really like to know if this is normal before proceeding. I don't know a lot about CCFL backlighting but from what I've seen, I can't see how this variation in backlight intensity is possible without there being some problem in the panel.

Any knowledgeable advice on this would be most appreciated.

photo links:
0% - https://pzt.me/7igb
10% - https://pzt.me/8n2d
20% - https://pzt.me/7bu6
30% - https://pzt.me/7xt0
40% - https://pzt.me/9os9
50% - https://pzt.me/5idw
60% - https://pzt.me/39lx
70% - https://pzt.me/1035
... // the rest are rather similar

 

[trungma]

Try moving back a few feet and I bet the screen will look uniform. BTW can you gently push the panel and see if it is slightly loose? The LCD panel is supposedly floating within the frame.

 

[tmr2L]

moving back did not seem to help. I could try taking another photo from further back - not sure if it's worth the effort as I won't be viewing from such distance anyway. The panel is indeed surprisingly loose ! this is most notable at the center, about 10cm from the bottom. Very gently pressing the panel there causes it to pop in a few millimeters, then pop back. While pressed the bright area surrounding the lower right corner grows in size. Now if only I could pull the panel out to see if the brightness decrease... The panel does seem to be better secured on the upper left corner, where colors look best, relatively.

 

[3lusive]

Hi, unless im mistaken that looks like absolutely horrible backlight bleed. I think you was just unlucky in that respect because every monitor can suffer from the problem, but that looks like a particularly bad case. Usually backlight bleed is only noticeable on blacks, and most panels suffer from it slightly but nowhere near as bad as in your display (some do but you just got very unlucky, at least that is the way it seems to me from the pics).

About the greyness part, I do not think IPS displays are that good in the contrast department - that is one of their weaknesses compared to PVA or even some TN displays. When I used a U2311 I also thought the overall contrast was poor and the black levels also quite poor (grey, washed out feeling to the image).

Regardless because the backlight bleed is so bad, I would ask for a refund or replacement immediately.

 

[tmr2L]

Thanks for the input. further search yielded some other folk having similar issues : http://en.community.dell.com/support-forums/peripherals/f/3529/t/19371978.aspx http://forums.guru3d.com/showthread.php?t=344296 not sure how much the AG coating has to do with this. Anyway I'm working with Dell on trying to get a replacement unit.