[Simon Baker]

wow, long time with no post in the English section!

Thought it might be a nice chance to get us all together again for a chat. I know DVL and XTknight both own the NEC LCD20WGX2 and Rasmus has tested it in the past as well. I've got one with me at the moment for testing but wanted to run something by you all as well.

How do colour gradients look on your screen? While I've calibrated the screen accurately with the LaCie Blue Eye Pro, the darker tones on test software like this show some obvious banding to me...

XT and DVL, can you test it on yours? DVM is off, screen is calibrated to 120 cd/m2 brightess, 6500k colour temp and gamma 2.2

[xtknight]

Howdy.

The fine gray scales show gradation but not banding (not banding like that caused by ACC). That's probably due to the high-contrast of the panel.

However, the gradation/posterization manifests itself in some 3D software like Blender. It's a little distracting:
(Look at the foreground side and on top of the cube.)

Standard DV mode (ACC off), ADVM off
Native white point
Gamma: L* (linear)
White level: ~120 nits
Black level: 0.20 nits
Contrast: ~575:1
Calibrated with basICColor (ICC v4.2)

It seems that this would happen on any 8-bit high-contrast display, but if not, I'd sure like to know what causes the gradation. I see gradation all across the color gradient program.

I was experimenting with some gradient algorithms in the lab (well, my house).



The top just shows steps of gradually increasing luminance (a typical gradient, RGB(1,1,1)->RGB(2,2,2)->RGB(n,n,n)). The bottom is a dithered/smoothed gradient. This is done by varying the channels across the gradient. The bottom has significantly less gradation for me. People with S-IPS LCDs and AG CRTs notice it the easiest.

[Simon Baker]

Hi XT, thanks for the reply. It's interesting since these issues are not really discussed that i've seen, certainly not to the scale of the moaning about the Dell range!

When I load up the colour gradients i don't get severe banding like that seen from the early release Dell 2xx7 models (Faroudja and ACC enabled), but there is obvious stepping in the darker shades, with visible lines...i'll take a picture when i have chance and post it as well