photon78s To summarize the information you shared (and the links), laptop displays tend to have generic connectors, with only a few common variants? So finding compatible replacement panels is perhaps easier than I envisioned.

It appears that these panels (compatible with the Thinkpad T480) incorporate their backlights, rather than having the LCD only which would require re-use of the original backlight (like recent MacBooks). Is this correct?

Did you ever personally try a 6-bit panel in your Thinkpad to see how Windows handles this? As I stated in another topic, I tried a few HP ZBook models and they seem to have 6-bit panels (with Windows recognizing the displays as 6-bit), and the pixellation and colors suggest the screens are running at true 6-bit in Windows. I am currently exploring how this is triggered. Unfortunately, EDID manipulation of an external display to set it to 6-bit color does not do the trick. I am assuming most laptops will dither a 6-bit display to 8-bit, but I am not sure whether this is due to the inherent circuitry, BIOS/VBIOS, or something else.

The HP ZBooks do not feel like quality laptops to me (loose trackpad buttons, etc.), but if the true 6-bit displays could be replicated in better-built laptop like a Thinkpad, I would be interested in trying that. I had a Thinkpad T480 laptop in the past, and my only real complaint with it was the low keyboard rollover count, which made it beep at me if I typed too fast.

    macsforme To summarize the information you shared (and the links), laptop displays tend to have generic connectors, with only a few common variants? So finding compatible replacement panels is perhaps easier than I envisioned.

    I think you are correct. With the T480, I think their are three versions of eDP connectors corresponding to touch screen, FHD, and WQHD panel types. Don't know about other laptops. I am waiting for 01YR503 type cable for WQHD and I swapped out the touch screen eDP cable (01YR502) that came with my used T480 with cable type 01YR501 for testing the FHD HKC MB140CS01-4 which imo is not a safe panel due to PWM and FRC unfortunately. Once you have all three types of display cables, then you are free to try the full range of potential panels.

    macsforme It appears that these panels (compatible with the Thinkpad T480) incorporate their backlights, rather than having the LCD only which would require re-use of the original backlight (like recent MacBooks). Is this correct?

    Yes, the backlights are incorporated into the panel. If you are very careful due to the sensitive ribbon cables, you could take out the backlight and can convert it into a solar or even incandescent display. Instructions on spectrumview.com

    macsforme Did you ever personally try a 6-bit panel in your Thinkpad to see how Windows handles this?

    I want to try this but the 6 bit touch screen panel that originally came with the laptop (R140NWF5 R6) broke due to my clumsy fingers. It was also a terrible panel in terms of PWM.

    By now I've owned or had the chance of using T43p, T500, W520, T480s, and now experimenting with T480. My best eyestrain free recent memories was the T480s with B140QAN02.3 in 2018 running earlier windows 10 of 2018-2019. That was also running on intel UHD 620 iGPU. This corresponds with what DisplaysShouldNotBeTVs posted. Maybe it was also panel lottery.

      7 days later

      photon78s id imagine it could make it less of a problem possibly since the refresh is so high? 🤔

      Hopefully someone can try it 😅

      photon78s

      In theory, the pixel inversion will be around 240Hz so will also be harder to capture. If someone is less sensitive to very high frequency flicker, this might be worth a look.

      "The last of the old will always be better than the first of the new" -engineering saying?

      Good to have in mind when searching for products.

      photon78s

      Finally installed B140QAN02.0 glossy wqhd screen in T480 that originally came with FHD touchscreen. Replaced display cable to 01YR503 type and had to file down and remove the bottom standoffs from the screen lid in order for the new screen to fit. The wqhd screen is a bit wider on the bottom than the FHD screen where the panel electronics and ribbon cables are located. Screen is on first glance much brighter and more vibrant than any of the FHD panels I've installed previously.

      Will add test results here (T480 running stock Linux Mint 21.3 Cinnamon):

      Polarization direction: screen is black through polarized sunglasses viewed horizontally. Many other displays is black only when sunglasses are 90 degrees vertical..

      300 fps 100% brightness PWM test footage on gray background (unedited out of camera 355 MB video file)

      20dB photodetector sensitivity:

      This is a better result than the previous T480 compatible FHD panels (see post)

      40dB photodetector sensitivity:

      No screen I've tested shows flat signal at 40dB sensitivity. Note the 60Hz dips

      Screen has poor color spectrum even for LED displays. Ra value is low at 56.7 when sampled on white patch of screen with no software color adjustment.

      The R9 value/score (deep red) is extremely low meaning that it cannot reproduce deep red tones accurately.

      White patch color spectrum results using QRedshift to adjust color temperature to 3000K (spectrometer reports as 2404K)

      :

      Pixel flicker is as expected significant when sampled from dark grey patch in lagom's gradient (left side of the upper gradient). This is without any tweaks to linux/compositor/rendering engine/intel graphics registries…

      https://imgur.com/a/P4MdyWi

      5 days later

      Spectrum of some cheap "Vekkia" led reading lamp:

      40dB sensitivity with photodetector shows this relative lack of flicker. You can compare with testing of monitors and devices and realize that this is excellent even against the other results from testing at lower 20dB sensitivity.

      the lamp looks good! how do u measure spectrums… which tool and software?

        simplex

        I use Hopoocolor HPCS-320. The cheapest model. However, it's still good for general between device comparison. It generates those data reports on device.

        I took 300fps video of the lamp and ran the video through FFMPEG video difference analysis using the command from the Stillcolor post. I see what may be subtle color shifts or color-to-color flicker about every 20 or so frames. However, I still need to rule out camera problems. I have a camera than can do max 1/32000 sec shutter speed and 1/25000 sec in 300fps videos so camera noise is a problem.

        Update: I used the same camera settings and did video diff for video clip of a sunlit window. I see the same flicker so I suspect that is just video compression artifact.

        The lamp is battery powered.

          With such high-speed camera you can record your 7i laptop to detect some vcom patterns, in my theory manuf increases framerate to mask such patterns more, but still not enough

          simplex

          No I have not. Isn't having blue peak with less/shorter wavelength potentially more harmful?

            photon78s \

            I think it harmful, but what is " low blue ligth " or " less blue light " defenitions is… if all blue monitor peaks are in safe nm ranges. Not sure how red ksf phosphor peak matter, compared to low red peak in panels

              simplex

              As others have noted before, this low blue light certification might be distracting from other more significant issues.

              20 days later

              Flickering 4k OLED screen (model ATNA60YV04-0 by Samsung) used in some 16 inch laptops. Setting Windows night light value to 38 results in almost equal spikes. Edit: causes eyestrain/headache for me so unusable.

              photon78s My question would be if certain low quality panels like probably on the T480s flicker more and more over the course of the day due to poor manufacturing tolerances/design and thus contributing to the computer work fatigue over the work day (you feel fine in the morning and later more and more fatigued as the screen silently increases the flicker to add to that fatigue).

              I do know that as the LCD warms up, it will flicker more because the liquid in the LCDs becomes more viscous. In my testing (which isn't necessarily comprehensive), my monitors reached a steady-state temperature and flicker after about 15 minutes.

                GregAtkinson

                I read sometime similar in Eizo documentation about letting the display warm up for color accuracy. Perhaps something else is the cause that has intermittent behavior.

                You might be interested in this paper on OLED flicker from 2020 if you haven't read it already:
                https://ledstrain.org/d/2652-eyestrain-from-oled-monitorstvs-but-not-oled-smartphones-a-theory/23

                  photon78s Perhaps something else is the cause that has intermittent behavior.

                  In my experience, some panels temporarily disable pixel inversion under certain conditions. For instance, for some panels, I can only see the pixel inversion when the image only takes up a small part of the screen. And once I display a large image, it isn't enough to make the image smaller - I have to make the image smaller, then maximize a different window (like I am somehow resetting the screen) and then bring up the smaller image and then I can see the pixel inversion. And it isn't just my eyes playing tricks on me because the photodetector is detecting the same thing.

                  That's a pretty specific example and it might not apply to your situation, but it does indicate that pixel inversion can be intermittent.

                    GregAtkinson

                    This is not directly relevant I think to pixel inversion but this oled paper does make me suspect some limitation inherent in the engineering of screens that is causing these behaviors:

                    Improving Flicker of Low-Refresh-Rate Driven Active-Matrix Organic Light-Emitting Diode Display
                    https://ieeexplore.ieee.org/abstract/document/9852200

                    We propose a novel driving method to suppress the brightness variation by applying a high voltage to the source and drain of the DTFT during the non-emitting time which is inserted periodically for dimming the organic light-emitting diode (OLED) display. Our experimental results show that the brightness variation can be reduced from 3.7 % to 1.4 % at the 63rd gray level by the proposed DTFT reset scheme.

                    I don't understand this statement (flicker at low frequencies?):

                    Especially, brightness stability could become a critical problem because human sensitivity to brightness is increased under lower refresh rate

                      dev