U2410 monitor in standard mode - gamma incorrect

Modern graphics cards have 10bit internal LUT both in VGA and DVI output, but in DVI output it downmix to 8bit at last,and in VGA outpu it DAC to analog signal.Then LCD recieve the signal,In DVI it recive 8bit, But in VGA, Modern LCD mornitors have a 10bit ADC.so it recieve 10bit.Althougt have some noise,But it's really 10 bit without downmix.

That's why you  use the DVI output you also get banding after calibration. If you use the VGA you do not get any banding.

Fudong, that`s really interesting and I believe you. Some questions:

If you have a 10bit LUT in DVI, isn`t the purpose that no matter what you do to the LUT (calibration etc.) at least 256 levels/color will remain? That would mean, you get 256 levels before and 256 levels after calibration. So why is there banding after calibration?

The U2410 can output 10bit color (8bit +some kind of dithering). Lets assume that I had a software that could output 10bit (Photoshop cannot as of now!):

You say that modern LCDs can receive 10bit per VGA. So I should be able to get 10bit from my software to the display output of the U2410, right? In DVI I cannot, because DVI is always 8bit. But what about display port? Assuming that I had a graphics card that can output 10bit via display port (the Quadros can), does the U2410 take 10bit per display port? And what about HDMI? What I`m after is I want to have 10bit on my display and the U2410 should be able to do this (like 2 of the newer Eizos do, which actually use the same panel).

"no matter what you do to the LUT (calibration etc.) at least 256 levels/color will remain" this is not true.no matter how many bits the LUT had,if you downmix to 8bit at last, then level will be lost. if you decide that level 64 is too light,the only way to calibrate it is set level 64 to 63 or less.right?

8bit enough for human's eye,what the benifit of more bits is on calibration.When you ajust gamma for a picture in Photoshop,then levels lost before it be send to graphics card.then graphics card calibrate gamma again,then level lost again,then monitor ajust gamma .......so you get banding at last.Tragedy happened again and again.

If graphics card can connect monitor with 10bit,then it will happened only one time, that's better.

Now the question remains, wether the U2410 can take 10bits via display port or HDMI. You said, VGA could do it , but I don`t want to use VGA.

And I`m still not sure wether I get what the actual purpose of a 10bit LUT in the DVI is, if you still get banding. Would you get even more banding if the LUT was only 8bit?

Would you loose even more levels in an 8bit LUT?

P.S.: I´m still not sure about what you said about the VGA output. You said it`s 10bit output. But isn`t that also depending on the operating system (as far as I know XP could not handle 10bit output. Windows 7 can, but not sure about Vista). And isn`t it also depending on the card driver? With my Geforce 8600  (and I guess with nearly every card) the maximum color depth I can choose is 32bit, which is 8bit/color and 8bit Alpha. There`s no option for 10bit/color.

Yes,VGA is not the right solution.Although it has more bits,but it need more calibration.DAC,ADC,Contrast ajust ,Noise Reduction.......All of these will hurt details of the signal.that's why VGA need 10bit to "squander".

When you do some fractional arithmetic,if you need 2 digits after decimal point in results.you have to reserve 3 in process.10bit LUT help  calibration loose less levels in the same way.

Ok,level 64 is a little too light.a 8bit LUT will set it to 63 at once,but a 10bit LUT do some more work to decide which one is better,set it to 63 or let it stay at 64.

Okay, I`m understanding more and more. But still having questions (as already written in my previous post):

If I have the right card (for example a Quadro) and the right software, then I can output 10bit per channel via display port. Do you know, wether the U2410 can "accept" 10bit via display port? And what about HDMI?

Sorry I don't know.I don't have a Quadro,and the HDMI on my card can not support deep color.......... I want some one tell me about this same as you. 

* Go here
* Open the Monitor FAQ (Frequently Asked Questions)
* Open 10bit (DP, HDMI) vs 8bit

"go here" ? Where? There`s no link.

Finally found some Monitor FAQ:http://en.community.dell.com/forums/p/19240747/19366842.aspx#19366842

But nothing about "10bit (DP, HDMI) vs 8bit".

Sorry, go here and open the FAQ.

"If your monitor has 10bit (DP, HDMI) and your video card has 8bit+FRC, the monitor will display 10bit"

What is FRC and which graphics card has it?

I confirm.. no banding issue with VGA connection (even with heavy modifications in the gamma curves).
Regarding the 10 bit/color output, I think that modern video cards can handle it. Look at the Radeon 4870 specs:

Full 30-bit display processing
Programmable piecewise linear gamma correction, color correction, and color space conversion
Spatial/temporal dithering provides 30-bit color quality on 24-bit and 18-bit displays
High quality pre- and post-scaling engines, with underscan support for all display outputs
Content-adaptive de-flicker filtering for interlaced displays
Fast, glitch-free mode switching
Hardware cursor
Two integrated DVI display outputs

Primary supports 18-, 24-, and 30-bit digital displays at all resolutions up to 1920x1200 (single-link DVI) or 2560x1600 (dual-link DVI)
Secondary supports 18-, 24-, and 30-bit digital displays at all resolutions up to 1920x1200 (single-link DVI only)
Each includes a dual-link HDCP encoder with on-chip key storage for high resolution playback of protected content4
Two integrated 400MHz 30-bit RAMDACs

Each supports analog displays connected by VGA at all resolutions up to 2048x1536
DisplayPort output support

Supports 24- and 30-bit displays at all resolutions up to 2560x1600
HDMI output support 

Hm, strange. How can the Radeon supply 10bit color via DVI, if the general DVI specification is 8bit (isn`t it?)

Let me sum up, what I "know" about the U2410 after reading all the threads.

- red/green tint problem

  Solution: hope to get one, that deos not have the problem

- sRGB/Adobe RGB dithering problem

Solution: Don`t use this mode

-standard mode has a gamma of 1,8. I need 2,2. Calibration via VGA has no banding, but VGA has many other disadvantages. Calibration via DVI exhibits banding. Calibration via display port? Maybe a solution, but only the expensive Quadro and Fire Gl have 30bit display ports.

- According to a german PC magazine the lowest brightness you can get is 120cd/m. From my more than 10year experience in digital imaging I can say that 120 is still a bit to high, if you want to compare screen to print. 100cd/m would be better (at least for me).

Solution: Even stronger calibration with even more banding?

Backlight bleeding (edges)

-Solution: none

Overall solution: Buy an Eizo?

The monitor is labeled as "DreamColor". To me this sounds more and more like "NightmareColor".

I was (and still am) very interested in the monitor, because of  wide gamut, 12bit processing (what about the LUT btw.?) 10bit output and 24inch at an affordable price.

But there seem to be many problems. Is a new firmware going to help? And when?