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Products to try or avoid? PWM Flicker and Temporal Dithering Testing
I think it would be even more helpful to add frequencies and flicker percentages, too.
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what are the phones that don't work for you beyond what you've mentioned previously? have you noticed any commonalities and correlations across these bad devices like the screen type, flicker depth, frc pattern, os versions? perhaps any unexpected commonalities.
have you tried putting electrical type over any front facing cameras and any IR infrared light emitters?
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photon78s
I'll just list all my bad mobile devices:
iPhone XR, se 2020, iPhone 11, xiaomi 13, Xperia 1 V, honor magic 6 pro, honor 90, xiaomi 13t, edge plus 2023, moto g stylus 5g, xiaomi pad 6. I think that's all, if I forgot any ill edit. I'm currently using the honor 90 and it's making me feel zombied/disconnect feeling. The higher pwm devices seem to be a little better in darker lighting conditions I noticed but none are symptom free. Every iPhone gave me instant dry eye and so did the xiaomi 13 (non T) which I'm assuming is from dithering/frc? Every device gives me blurry distance vision and slight double vision. The 13T wasnt perfect, I was still able to function but it started compounding and affecting me sadly.
Also something recently made me feel really not so well which I think was when I was playing around with the brightness on my uprtek mk350n light meter(visible bars with 1/4000 SS)
Devices up next to try is cat s62 pro, vivo x100 pro and daylightco tablet. I did also preorder the light phone 3 but I'm not sure if I should cancel that.. they say it's true hardware dc dimming but not sure if the refresh dip may affect me of the grayscale OLED it uses
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Also did try that humane ai pin phone which the "trust light" alone made me feel awful since it color flickered so I returned it. The laser projector seemed to bug me too on it.
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Slow motion footage show the front ir sensor flickering on many phones including the ones I've tested above. Covered up just to be extra cautious.
Interesting and perhaps disappointing that the light phone went from e-ink to oled…
dasung has the e-ink phone monitor but last I checked it was still buggy and awkward to use…
https://shop.dasung.com/products/dasung-6-7-e-ink-phone-monitor-link
Generic smartphone to PC screen mirroring software:
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.
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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.
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Alienware aw2524h
8 bit + FRC 480Hz (non-overclocked mode) monitor
https://www.tomshardware.com/reviews/alienware-aw2524h-500-hz-gaming-monitor-review
I interested in how the 480Hz refresh rate might impact eyestrain and dithering sensitivity.
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"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.
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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…
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the lamp looks good! how do u measure spectrums… which tool and software?
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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.
photon78s I use Hopoocolor HPCS-320.
Have you come across devices with a blue peak less than 445nm?