WinDAS White Point Balance guide for Sony Trinitron CRTs

brownvim

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My setting was wrong in display image parameters, changed it to 0 - 255, thanks spacediver.

i redid my results, haven't tried the Argyll yet, its getting darker though.

1589135073131.png


im getting better DE numbers now, gamma has moved alot.
 

spacediver

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I’ll try the Argyll steps next, I didn’t do anything with them first time round.

Graphics card is a 980 Ti.

I want those inky blacks but it’s still day time here and the room has white walls!

excellent, that means you have 10 bit precision for LUT adjustments (I have same card as you btw).
 

brownvim

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dispcal -m -qm -J -F -G2.4 -f0

I tried that and i get the following error:

1589136472238.png


Edit: Dont matter, i had to remove the -J to get it to work.
 
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Hello, I have one question before i post my results. Do I have to make wpb for 6500k and 5000k if I use only 9300k? I just clicked OK on steps with that.
My monitor is Dell P1130, it has some addiontal steps not contained in guide like contrast_min.

After adjustments monitor sets thier brightness and contrast to 50/85 below 50 i loose black details.
 
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spacediver

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Hello, I have one question before i post my results. Do I have to make wpb for 6500k and 5000k if I use only 9300k? I just clicked OK on steps with that.
My monitor is Dell P1130, it has some addiontal steps not contained in guide like contrast_min.

After adjustments monitor sets thier brightness and contrast to 50/85 below 50 i loose black details.

I don't think you have to worry about the other color temps if you're not going to use them. I always do all three just because I'm a bit OCD and it only takes a few extra minutes.

Curious though, why are you using 9300k and not 6500?
 
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without.PNG

This is my results after WPB. I did not do gamma adjustments in nvidia panel beacuse i use two displays and that thing just doesn't work.
The problem is 100% white is only 75 cm/m2 and i can't see difference between black and one more bar next to black bar in file grayscale_16bars_1920x1200. It blends into one black color. I can see it if i go much more in brightness OSD but then i don't have real black.

My G2 is real black at 137.

I'm using 9300k because it looks more professional for me. I use flux so it's getting more yellow in night.
 

spacediver

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I bet if you plot your gamma curve it will show a higher than normal gamma. If you want to set G2 low, you have to do a LUT adjustment afterwards to restore gamma to a normal level, else the picture will be crushed. And the best way to do this is with argyllCMS as per my guide (I think there's probably a way to do this for dual monitors so you have a diff LUT for each output, but not sure).
 
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So it's completely normal to have crushed low black level without gamma adjustments? I'll try it thanks.
Isn't 70 cd/m2 too low? I have contrast at default 85 but on 100 isn't much difference.
And it's strange for me to have 50 brightness all the time when before i have to make it on 0 to have real black.
 

jbltecnicspro

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So it's completely normal to have crushed low black level without gamma adjustments? I'll try it thanks.
Isn't 70 cd/m2 too low? I have contrast at default 85 but on 100 isn't much difference.
And it's strange for me to have 50 brightness all the time when before i have to make it on 0 to have real black.

You have to keep in mind that everything is relative. If you set your G2 too low then your maximum white level will be compromised too.

My opinion - if you just follow the white point balance procedures on windas in a darkened room (I usually did it in the same light-controlled settings as I would use daily), then a value for 50 brightness will be dark enough with some headroom to take it lower if you wanted to.

This means that you will try to hit the targets just as it has you do, as you do the procedures. 75 nits for 9300k seems way too low.
 

Enhanced Interrogator

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If you have no way of adjusting the gamma curve of the input device, then your best option is to set the G2 level so it's not super dark black.

I'm considering doing my first WinDAS calibration on a Dell P992, and this is my hangup. I have to aim for near 2.2 gamma, because I use game consoles with my monitor, and I'm not so sure custom LUT's will work with DX12 and Vulkan games, since those API's are "closer to the metal" and might ignore any color correction at the OS level.

Currently, if I drop my brightness enough to get a deep black, my gamma is at about 2.35 (according to the test image on lagom.nl). Is the general consensus that this will always be my monitor's gamma when I drop brightness close enough to get true black, even after a WinDAS G2 adjustment?

If so, I'm wondering if purposefully setting incorrect, higher values for the 30IRE step could help me lower gamma slightly? That seems like the only step in the WinDAS procedure that isn't either maxiumum black or maximum white. Or is one point of adjustment too rough to give me a better gamma curve?
 

jbltecnicspro

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I'm considering doing my first WinDAS calibration on a Dell P992, and this is my hangup. I have to aim for near 2.2 gamma, because I use game consoles with my monitor, and I'm not so sure custom LUT's will work with DX12 and Vulkan games, since those API's are "closer to the metal" and might ignore any color correction at the OS level.

Currently, if I drop my brightness enough to get a deep black, my gamma is at about 2.35 (according to the test image on lagom.nl). Is the general consensus that this will always be my monitor's gamma when I drop brightness close enough to get true black, even after a WinDAS G2 adjustment?

If so, I'm wondering if purposefully setting incorrect, higher values for the 30IRE step could help me lower gamma slightly? That seems like the only step in the WinDAS procedure that isn't either maxiumum black or maximum white. Or is one point of adjustment too rough to give me a better gamma curve?

You're overthinking it - big time. Adjust the G2 in the light-controlled environment that you use it, and hit all of the targets. Once you're done, you should have enough brightness range to get the blacks as inky as you want without sacrificing too much gamma. Unfortunately, if you're running the CRT "raw" (no gamma adjustment) then there will be some give and take. I've personally found 2.4 gamma to be just fine in a light-controlled setting. So long as you can clearly see the bottom IRE's then you have nothing to worry about. My two cents.
 

spacediver

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You're overthinking it - big time. Adjust the G2 in the light-controlled environment that you use it, and hit all of the targets. Once you're done, you should have enough brightness range to get the blacks as inky as you want without sacrificing too much gamma. Unfortunately, if you're running the CRT "raw" (no gamma adjustment) then there will be some give and take. I've personally found 2.4 gamma to be just fine in a light-controlled setting. So long as you can clearly see the bottom IRE's then you have nothing to worry about. My two cents.

I trust jbl's experience here over mine, since I've not done any real experimentation on this front.

It's a good question though. I'm pretty sure there's a systematic way to achieve a desired target gamma with hardware calibration alone. You could figure it out through modeling of the involved currents, or you could generate some insights through experimentation. And yea having brightness adjustment available post hardware adjustment opens up possibilities.

Cool thing is that it's straightforward to measure gamma, so you can get quick feedback on any adjustments you do.
 

jbltecnicspro

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I trust jbl's experience here over mine, since I've not done any real experimentation on this front.

It's a good question though. I'm pretty sure there's a systematic way to achieve a desired target gamma with hardware calibration alone. You could figure it out through modeling of the involved currents, or you could generate some insights through experimentation. And yea having brightness adjustment available post hardware adjustment opens up possibilities.

Cool thing is that it's straightforward to measure gamma, so you can get quick feedback on any adjustments you do.

I haven't really "experimented" perse. I just know that when you do the WPB procedure, you end up with a pretty decent range of adjustments when you're all said and done. Especially on the CR1 chassis models, which default you to 50 brightness. The FW900 may be a little more restrictive though as it defaults you to 31 brightness when you're done. So maybe you'd do it a little "darker", so to speak. After all, you could always turn the brightness up. :D
 
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Enhanced Interrogator

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I haven't really "experimented" perse. I just know that when you do the WPB procedure, you end up with a pretty decent range of adjustments when you're all said and done. Especially on the CR1 chassis models, which default you to 50 brightness. The FW900 may be a little more restrictive though as it defaults you to 31 brightness when you're done. So maybe you'd do it a little "darker", so to speak. After all, you could always turn the brightness up. :D

Currently, with my P992, turning brightness up to achieve 2.2 gamma washes out the rest of the colors slightly. To get blacks that I'm satisfied with, I have to turn brightness down, which gives me a 2.35, approximately. With many of my games, this is just too low, as shadow detail just gets lost in high contrast scenes.

And I have a LaCie Electron22BlueIV to compare it to, which has almost spot-on 2.2 gamma when I have brightness set to a satisfactory black level.

But my current setup with P992 is definitely wonky. I'm in the custom color mode, and I'm eyeballing RGB gain and bias to get an approximate 6500k. And it's clear something is wonky with my G2, because I have R bias is set to 0, while B and G are set to 70-80. Gain on the three channels is pretty equal. Whenever I try to use the standard modes like 6500k and 9300k, everything is too red.

So I'm guessing WinDAS will let me avoid all that headache, and just use the default 6500k mode that should have a more linear response. But from what I've read in this thread, I shouldn't expect gamma to change significantly? Or am I wrong about that?
 

spacediver

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Yea it's pretty remarkable how much shadow detail you lose when using 2.4 to view stuff mastered in 2.2. That's why I generally create a couple LUTs.

I'd follow jbl's advice, and dive in setting the G2 to a reasonable level (keeping in mind that, at least in my experience, the black level during the G2 adjustment is lower than the resulting black level after the calibration is over (see my post here).

Just thought of an idea you can try:

After setting each of the G2 levels (there are two successive G2 adjustment steps), but before hitting OK, load up the full white image (included in the zip in my signature), and measure the luminance, and take a note. That way, if you decide to do a subsequent WPB, you can adjust more intelligently.

Not sure how changing the other targets will affect things - my hunch is that there is probably only one "solution" that provides a given gamma, and that solution includes a particular black level. I could be wrong though.
 

Enhanced Interrogator

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Thanks. I figure if I'm not satisfied after the first run, I'll run through a few more times, taking notes. If the first two G2 adjustments don't get me where I want to be, I'll go off-spec and try tweaking the 30 IRE step.

And something I'm not sure anybody's mentioned, is the HD Fury has (had?) a device called the Gamma X, which can tweak gamma in on RGB signals. Also, the Crescendo Systems RTC2200 has a gamma tweaking capability.

I figure if I can't get to where I want to be with WinDAS, I'll try one of those solutions.
 
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I did WPB for Dell P1130 but everything looks way too reddish. I have to set G2 to 86 to have real black, isn't it too low? I don't have much info about this monitor. Can it have resistor on G2?
 

jbltecnicspro

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I did WPB for Dell P1130 but everything looks way too reddish. I have to set G2 to 86 to have real black, isn't it too low? I don't have much info about this monitor. Can it have resistor on G2?

Did you just stop at the G2? If you finished the process correctly it shouldn’t look reddish.
 

spacediver

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something went seriously wrong. Did you reset your LUT before doing the adjustment, as per the guide?
 
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I didn't put cloth over CRT and colorimeter. I did it once again. White is now white, black is nearly real black but gray is reddish, and i had to put G2 around 90. I'm really concerned that some G2 resistor has been replaced.

hcfr before: hcfr after: dispcal before: dispcal after:
 
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spacediver

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I'll ask again: Did you rest your LUT before doing the adjustment?

When you say you "had to" put G2 around 80, what do you mean?
 
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I didn't have custom LUT. In nVidia panel everyhing is default.

I have to put G2 to 86 to have real black but I use 90+ beacuse it's nearly real black.
When I have to adjust G2 the image (when g2 is too high) isn't gray like in normal crts but reddish/violet. Maybe that's the problem?
 

jbltecnicspro

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When I have to adjust G2 the image (when g2 is too high) isn't gray like in normal crts but reddish/violet. Maybe that's the problem?

When you first start the WinDAS white point balance procedure, the program resets the drive and bias levels to a default level. It guaranteed will look off at first. You then have to set the G2 value such that on a 10-step black-to-white pattern, 0 IRE is black - invisible really and that 10 ire is barely visible. Next you have to hit all the requested targets for whatever color temperature presets are available for your particular monitor/chassis. It will depend on the screen being calibrated. For example, the FW900 has you adjust 9300K, 6500K and then 5600K. Once you're done with the white balance adjust everything should be on target, as far as grayscale is concerned.

The ONLY time I'd recommend taking her apart and messing with the electronics is when you cannot hit the targets requested by WinDAS. Even then I'd start by checking to see if the tube emissions are fine using a CRT rejuvenator/tester. If you have a good tester, you should know pretty quickly if you have an issue with the tube.
 
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Thank you for information. I didn't do 10IRE black check, but it's not that important at this moment. Problem is it too reddish in middle colors. Note that my Dell has 30k hours of work. I'll check if resistors were replaced at first.
 

jbltecnicspro

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Thank you for information. I didn't do 10IRE black check, but it's not that important at this moment. Problem is it too reddish in middle colors. Note that my Dell has 30k hours of work. I'll check if resistors were replaced at first.

I don’t think you’re registering. If you compete the procedures as directed by WinDAS it should look fine. The reddish hue you’re referring to would be taken care of by adjusting the drives and biases as directed and with your measuring device.
 
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I checked resistors and there are no new resistors and existing resistors are the same as in service manual. The values of resistance are also OK. The voltage of G2 is 540v.
I had problem that monitor were resetting the OSD settings. Now it remember settings, idk what happened.
My Dell has 30k hours on time so I think it's pretty much worn out.
I'll try do WPB again, this time at night.
 

Hike

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Hello everyone, I encountered a strange phenomenon when using windas for white balance adjustment Sony CPD-G520.
When I go to step 48, das prompts to use a white image. When I display a white pattern on the full screen, the brightness of the entire screen will immediately decrease. The white brightness of DTP-94 test is about 50 nits.
I don't know where is the problem? When I calibrate my other Dell P1110, everything works fine.
Has anyone encountered the same problem?
 

spacediver

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After going through the entire procedude, and hitting the recommended targets, how many nits is white?
 

Colth

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Hello, I have a Sony GDM-F520 which i'm trying to correct. A purely black screen has a red hue, turning down the brightness in the OSD to get a good black level crushes the dark areas in films and games. It also a red/purple hue over the monitor, especially on dark areas. Could I do both of these through a colour profile or OSD adjustments, or should I do a windas calibration? I have a i1 Pro colorimeter.

The monitor is connected to my computer through a Vention usb c to vga adaptor (model number: CGMHA) and a RTX 2070. Is it possible to do this guide with the Vention usb c to vga adaptor?
 

jbltecnicspro

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Hello, I have a Sony GDM-F520 which i'm trying to correct. A purely black screen has a red hue, turning down the brightness in the OSD to get a good black level crushes the dark areas in films and games. It also a red/purple hue over the monitor, especially on dark areas. Could I do both of these through a colour profile or OSD adjustments, or should I do a windas calibration? I have a i1 Pro colorimeter.

The monitor is connected to my computer through a Vention usb c to vga adaptor (model number: CGMHA) and a RTX 2070. Is it possible to do this guide with the Vention usb c to vga adaptor?

You lucky bastard. :) Yes, as spacediver said you would benefit from a WinDAS calibration. Forget about profiling until after you've gone through the WPB. Good luck!
 

Colth

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After going through the windas white point balance procedure the red/purple hue is gone, the colors look natural to the eye.
Although I'm not sure what I did but the black levels are still elevated, with a white/blue hue. This is at the default settings of 85 contrast, 50 brightness. I'm wondering if these are just too high? I turned the G2 down from 160 to 146, using the two tone grey scale image until they were indistinguishable in a very dark room last night. What would you suggest; can I just set the G2 lower by editing the dat file and testing in steps or should I do the whole process again?
 

Colth

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What pattern did you use to set the G2?

With the PDF of this guide (in post 568) there is "Grayscale_2_bars_1920.png". It is the first two bars of a 16 tone grey scale. The first post says to make them indistingushable and use that as the adjustment.
 

xykreilon

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Hello, I recently saved a Hitachi SuperScan Elite 751 from being trashed by my relatives. I calibrated it with DisplayCAL using proper settings (white level drift compensation, 6504K color temperature, rec. 709 target curve, etc.) and got this:
CM751_callibrated.png

CM751_callibrated_gamut.png

But, beyond that, is there anything more I can do to reduce the black levels without reducing the brightness of the monitor? It seems to be an inherent issue I can't get around, seeing as the only way I've found to make blacks inky on this monitor is reducing the brightness through the OSD. However, I would be happy to be enlightened and/or realize I've missed something in this thread.
 
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