Gamma nonuniformity in 30" 2560x1600 monitors (and 27" 2560x1440)?

[MetaGenie]

My Dell 3007WFP-HC dismally fails this Lagom LCD test. This is what it looks like, as seen from a distance of 3.14 meters:

The "lagom" is supposed to blend into the background everywhere. At the very least the pattern should be uniform.

I knew that this monitor was dimmer towards the edges, but I assumed it was a linear effect (like vignetting on a camera lens); I was fine with that. But gamma nonuniformity is much worse than mere brightness nonuniformity! An image should locally look identical no matter where it's displayed on the monitor. On this 3007WFP-HC the gamma is all over the map; it ranges from 2.29 (in the center of the blending blob) to 1.39 (at the lower-right corner), for the luminances used in that lagom test pattern.

Do other copies of the 3007WFP-HC have this problem? What about other 30" LCDs, especially the NEC 3090WQXi (both in native/uncalibrated, and calibrated + uniformity enabled), and how about the 27" iMac?

 

[MetaGenie]

Bump.

Please, anybody with a 30" LCD or 27" iMac, just take a look at the Lagom test (look at the screen from a distance to minimize the effect of viewing angle) and tell me if it's uniform or not. You don't have to post a photo of the screen. I need to know if this problem is specific to my copy of the 3007WFP-HC, general to all 30" LCDs, or something in-between.

 

[scanido]

I just got my 3007WFP-HC and beyond the intially size reaction, I have to say i am not too impressed with the quality thus far.

I will run your test this evening but i wouldn't be surprised if i get the same results.

So far my biggest issues are:

- Extreme backlight uniformity issues. Each corner is noticeably brighter from a black background.

- The LCD screen appears to not be fastened to the frame. I can move the top LCD quite a bit near the top.

- The biggest issue is that when viewed from an angle on a black screen, the display doesn't look black at all but really grey-white.

 

[isp]

just got my 4890 today and hooked it up to the imac (calibrated as well) so I finally can move past the 20wmgx2 after all these years...

This test - http://www.lagom.nl/lcd-test/viewing_angle.php

I would say it looks uniform. Lagom is not invisible at any part of the screen, just REALLY faint. There is an area at the bottom (extending about 2inches up from the bottom ...) where gamma is slightly higher than the rest of the screen. try to take some pics later, but I only have a crappy point and shooter atm...

Tiny bit on the left side as well. Maybe 1 inch inward is effected...

 

[MetaGenie]

Thank you, isp. Sounds like your 27" iMac's uniformity, even if not perfect, is much, much better than my 3007WFP-HC's. If you do make a photo, just make sure it doesn't have moiré... that'd throw off the blending.

Any 3007WFP-HC owners want to answer this? Please?