hard to know the right "dithering" thread, but thought this was helpful from the displayCAL forum. (I havent seen much talk here of using monitor calibration software)

How do I know if a graphics card is capable of dithering?

Looking at a smooth grayscale gradient in an image viewer with color management turned off(!) is usually a reasonable test. I.e. first look at it with the videoLUT set to linear (no calibration) to make sure banding is not in the image itself or introduced by the display (some panels are less than 8 bit and use dither internally to generate intermediate steps). Then load your calibration. If it still looks smooth, the graphic card either dithers, or ouputs a higher bit depth (both should suffice to reduce or eliminate calibration-related banding artifacts).

4 days later

So, the dithreing is done either in the LCD panel itself, either by the graphics card? Are there any panels that do not dither by default? Can we make a list of them? Is there any true 8 bit panel? Is there a test to spot the dithering simmilarly to the pwn one? (Seems like although it affects a lot of people, not many are aware of it)

    Alyosha2001 So, the dithreing is done either in the LCD panel itself, either by the graphics card?

    Correct. On laptops the LCD panel doesn't have much electronics of its own so it's often done by the graphics card.

    FRC is dithering, which is often used in desktop monitors, and if your using a panel with FRC and a graphics card that is dithering, it can cause issues with image quality.

    https://forums.macrumors.com/threads/10-7-1-update-no-good-getting-the-dell-u2211h-to-work-properly-on-a-2010-mac-mini.1022386/

    Is there a test to spot the dithering simmilarly to the pwn one?

    Very hard to do I'm afraid. I have some ideas that involve a microscope and high speed camera ($$$$)

        JTL FRC Very interesting article! I do happend to have a Dell with eIPS, and it does not use PWM for backlight, but gives me some kind of headache. The bad part is theese panels have dithering of their own and cannot be turned off in video drivers.
        Still I think the best way to spot the dithering nowadays is banding, until some prooves a 8 bit FRC-free panel exists

        • JTL replied to this.

            JTL I don't know, but I would like to. I also have headache with Sony mirrorless LCD's, with old Canon I don't

              20 days later

              I tried ditherig using the Disable All Dithering option and it doesn't seem to help in my work laptop, perhaps a little. Is there anything else I can try? Intel Graphics 510. I get headaches, dizziness, and burning eyes when using it for more than a few minutes. I hate going into work because I know I will have to sit there for hours and suffer looking at the screen.

              Have also tried flux and Gunnars, doesn't make a difference for me.

              • JTL replied to this.

                JTL Yes there's definitely visible banding. I notice it other places than that website. When I load that website and switch the options from "Disable all dithering functions" to "Spatial (Default)" you can see the banding disappear.

                So I think my problem might not be dithering; something else is going on. There still feels like there's something "moving".

                    ryans Maybe your screen has PWM on the leds. That is easy to check with a camera. One symptom of the PWM I noticed on many people at prolongued use is red eyes.

                        Alyosha2001 @JTL I took a video, would be grateful if you could take a peak. I don't think it's PWM since if I decrease the brightness from 100, PWM is very obvious. There still looks like some type of flicker going from left to right.

                        But, when I attach this laptop to a Dell U3417w, even with Ditherig installed, I see no banding. Perhaps because this is an expensive monitor and actually has 8-bit colors. However I still get eye strain with it. I'd be fine with eye strain from the laptop if I could get none with the Dell monitor.

                        Here's my video:

                        https://drive.google.com/file/d/18aKec17gTa_S5AgSUavvD3NycSijj75a/view

                        I'd consider getting my company to use my old Thinkpad T430s and image it, since it gives me no eye strain, but it doesn't support the resolution of the Dell monitor afaik.

                        I don't think I'm sensitive to PWM since I can use a Galaxy S5 (AMOLED screen with PWM) fine, but, I have issues with Macbook Pro (no PWM); perhaps PWM is not made equal (some is worse than others).

                        Thanks for all your help. Nice to know I'm not alone here.

                            I think that is PWM. The reason why it's horizontal is because you are holding the phone vertically. Not all PWM's can be captured with a phone camera, the high frequency ones are indetectable unless a DSLR or oscilloscope is used. And the reason the external monitor is not showing banding is because it cannot be disabled, since it is not driven by the videocard

                              Alyosha2001 Oh I thought the videocard does determine dithering on the external monitor? Interesting. And I see...when I make the brightness lower the PWM is very obvious. I didn't think PWM happened at 100% brightness but maybe this screen is particularly crappy. Thanks for checking.

                                10 days later
                                https://www.youtube.com/watch?v=OCDfn9IWc6g

                                took some video of what dithering looks like on a Dasung Paperlike Pro. I had to use a video because I have eliminated dithering (for the most part) from my setup. Microsoft seems to choose colors that dither preferentially. The youtube compression caused a loss of fidelity, ask me and I'll email you the original video

                                  ShivaWind E-ink definitely requires dithering because it is a 1-bit display technology.. something I remember well from black and white 9" screen Mac days. I looked up your monitor, says it has 3 dithering modes A2 which is black and white only, A16 which attempts to simulate 16 shades of grey, and Floyd which is their implementation of a Floyd-Steinberg algorithm for watching video with. Nice thing to have, enjoy it.

                                      Sunspark

                                      this is a better video

                                      https://www.youtube.com/watch?v=0y-I3hqQgCQ

                                      There is more to it than just the panel. There are colors that are fixed, and colors that dither. the dithering pattern can be sort of Celtic knots or like moving dots. there is dithering that always moves, and dithering that only moves when in proximity to a moving mouse cursor. I can say with certainty that the source of dithering is not the Dasung panel because the dithering pattern follows the mouse pointer in video other people have uploaded of thier computers to utube. so the dithering was following Their mouse, not mine.

                                          I can also see the difference between makes of video card or when I have dithering enabled for the video card using xrandr and when I have it disabled. The primary source is upstream of the panel. I am sure that the panel does dither, but the patterns here are too big and sparse to approximate Grey scale. they are definitely upstream,

                                          7 days later

                                          ryans I don't know if dithering.exe affects external displays or not.

                                            dev