OSX dithering - Help wanted

NewDwarf

I think the question of weather this works or not may come down to the bit depth of the display panel. There is a command to show what vendors display panel is installed. I don't know if the bit depth information might be available also.

Can you run this command and give us the output please?

ioreg -lw0 | grep IODisplayEDID | sed "/[^<]*</s///" | xxd -p -r | strings -6

A prefix of LTH is Samsung, while LP is LG. All the Samsung displays I have seen are 8-bit. With LG, it may be a mix depending on how old the panel is. The older LG are 6-bit. I am not sure of the newer ones. Again, I don't know what other information may be hidden in the output of "ioreg" (such as bit depth).

The above command will not work on M1 macs. It may or may not work on Monterey on Intel.

Well i think every manufacterer is saying true 8bit screen, but the monitor may have a weakness at some level with e.g. gray and dithers is always on as a choice of the manufacterer. True 8bit could be just "nearly true" 8-bit.

caboy There is more advanced option to get the display information by parsing the EDID blob. Below is my display.

00 ff ff ff ff ff ff 00 06 10 3e a0 00 00 00 00

10 1b 01 04 b5 1d 12 78 02 0f 81 ae 52 43 b0 26

0d 50 54 00 00 00 01 01 01 01 01 01 01 01 01 01

01 01 01 01 01 01 d9 65 00 50 a0 40 2e 60 08 20

08 08 1e b3 10 00 00 1a 00 00 00 fc 00 43 6f 6c

6f 72 20 4c 43 44 0a 20 20 20 00 00 00 10 00 00

00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 10

00 00 00 00 00 00 00 00 00 00 00 00 00 00 01 72

70 12 79 03 00 7f 81 3f fa 10 00 03 01 18 0f 28

17 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

4c 50 31 33 33 57 51 35 2d 53 4a 41 37 0a 20 00

44 43 4e 31 33 30 32 30 30 32 58 50 58 47 54 41

4b 0a 20 20 20 20 20 7f 81 29 fa 10 00 02 01 00

11 00 00 02 90 03 65 04 89 06 18 08 38 0b 20 0f

19 14 8a 1c 00 26 3d 34 51 47 ae 62 5a 87 21 b9

e3 ff 7d 00 00 00 00 00 00 00 00 00 00 00 b3 90

----------------

Block 0, Base EDID:

  EDID Structure Version & Revision: 1.4

  Vendor & Product Identification:

    Manufacturer: APP

    Model: 41022

    Made in: week 16 of 2017

  Basic Display Parameters & Features:

    Digital display

    Bits per primary color channel: 10

    DisplayPort interface

    Maximum image size: 29 cm x 18 cm

    Gamma: 2.20

    Supported color formats: RGB 4:4:4

    First detailed timing includes the native pixel format and preferred refresh rate

  Color Characteristics:

    Red  : 0.6796, 0.3203

    Green: 0.2646, 0.6904

    Blue : 0.1503, 0.0507

    White: 0.3125, 0.3291

  Established Timings I & II: none

  Standard Timings: none

  Detailed Timing Descriptors:

    DTD 1:  2560x1600   60.000828 Hz   8:5     98.761 kHz    260.730000 MHz (286 mm x 179 mm)

                 Hfront    8 Hsync  32 Hback   40 Hpol P

                 Vfront   32 Vsync   8 Vback    6 Vpol N

    Display Product Name: 'Color LCD'

    Dummy Descriptor:

    Dummy Descriptor:

  Extension blocks: 1

Checksum: 0x72

----------------

Block 1, DisplayID Extension Block:

  Version: 1.2

  Extension Count: 0

  Display Product Type: Standalone display device

  Vendor-Specific Data Block (0x7f) (Apple), OUI 00-10-FA:

    Type: 3, Version: 1

    18 0f 28 17 00 00 00 00 00 00 00 00 00 00 00 00 '..(.............'

    00 00 00 4c 50 31 33 33 57 51 35 2d 53 4a 41 37 '...LP133WQ5-SJA7'

    0a 20 00 44 43 4e 31 33 30 32 30 30 32 58 50 58 '. .DCN1302002XPX'

    47 54 41 4b 0a 20 20 20 20 20                   'GTAK.     '

  Vendor-Specific Data Block (0x7f) (Apple), OUI 00-10-FA:

    Type: 2, Version: 1

    00 11 00 00 02 90 03 65 04 89 06 18 08 38 0b 20 '.......e.....8. '

    0f 19 14 8a 1c 00 26 3d 34 51 47 ae 62 5a 87 21 '......&=4QG.bZ.!'

    b9 e3 ff 7d                                     '...}'

  Checksum: 0xb3

Checksum: 0x90

devilgrove

Can you give us more details about your macbook model please?

You said 16".

Which year?
Which GPU?
Which OS version do you have?

Thank you

NewDwarf

Thanks. I am trying to read through that now.

karut I also have the MacBook Pro 13'' 2015 but it doesn't have dithering by default. And yes, log show --predicate "processID == 0" | grep Dither

returns nothing.

NewDwarf

Interesting…I assume you also run the latest version of OSX Monterey. I will test the MacBook with an external monitor. The display should at least have no PWM according to Notebookcheck.

caboy my MacBook is actually a 16,2 meaning it's part of the 16th generation of MacBook Pros.

It'a a 2020 13" 4 TB3 running Catalina 10.15.7. It uses Intel Iris Plus from the Ice Lake generation.

caboy

I think the line with Bits per primary color channel: 10means that the GPU is a 10-bit GPU.

No. According to the EDID specification, this is "Basic display parameters". So, this parameter is not related to the GPU. Primary colours are Red, Green, Blue. So each primary colour can be sampled by 2¹⁰ levels.

Did anyone try this NVRAM technique and have eyestrain improve? I know it helped @NewDwarf. Any others?

devilgrove

Are you still having eye strain now with the nvram dithering = 0 thing?

caboy yeah, it's still there unfortunately, but it's way more usable. My old configuration (which was like 10-15 different things going on in the setup) was a 4-5/10 in terms of pain. This is like a 1.5/10, and for the most part uses macOS on its default settings other than the nvram argument, color profile, and font smoothing. I even have the resolution on default now, versus having to use the non-HiDPI resolution before. I'm gonna try to find a true 8-bit display to hook up my MacBook to so that I can test if it'll get rid of the last bit of strain.

ryans I would say the same answer as devilgrove, eyestrain improved from 4/10 pain to 1/10. Problem is that the banding is completely the same as before (at least on my MacBook Pro) so we have no objective way to prove it's not placebo and that it has a real effect

insta42014 it's 100% not placebo for me at least