Anything I can do to increase contrast ratio?

[mds83]

It’s a Dell S2417DG with reported contrast at 850:1 to 950 using the 6500k standards, according to review sites.  Such as pcmonitors.com or tomshardware.

Using the i1 display pro.

• This topic was modified 6 years ago by mds83.

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[Vincent]

There are many sources of such low contrast ratio:

• Bad unit. In order to check this reset monitor to factory config + check contrast ratio (CR) in an uncalibrated OSD mode with native whitepoint (WP)
• Native white point too far from daylight 6500K. WP correction implies some kind or CR drop, extreme corrections brings bigger CR loss. In order to check this reset monitor to factory config + measure coordinates of WP.
• Bad “6500K” preset. In order to check this reset monitor to factory config + measure coordinates of WP and CR.
• User error. When calibrating you change RGB gain, brightness and constrast in a wrong way, loosing to much CR. In order to check this set monitor in OSD mode you used for calibration with your calibration OSD configuration (RGB gain, brightness and such) + measure coordinates of WP and CR.

Reported Measured luminance: 50.3 cd/m² points to User error. Reset monitor to factory default values and calibrate again but  do not lower brightness so much, do not monify contrast and try to do not lower to much RGB gain control in OSD (if avaliable).

Since this Dell S mode seems to be a gamer display I do not find any useful scenarios for a 50cd/m2 target, you should aim for twice this brightness or more.

Edit: It seems that you aimed for a black level of 0.0802cd/m². This seems to be too much your your display capabilities. Set black level “As measured”, same for While level and find a confortable brightness setting (higher that your current settings)

• This reply was modified 6 years ago by Vincent.

[Vincent]

Edit: It seems that you aimed for a black level of 0.0802cd/m². This seems to be too much for your display capabilities.

Keeping nominal CR, I meant. CR drops in some displays when you lower brightness too much .

[mds83]

I followed the advice you gave me and here are the results.

I have done multiple cailbration tests using certain scenarios.

I always calibrate the monitor based on “custom color”.  At factory default its RGB all at 100.

At 6500k with a brightness range from 50 and 120 cdm2,  the contrast ratio is anywhere from 550 to 650.

However, I get a better contrast ratio by using the “as measured” at whitepoint.  But its at 6000k.  Thats a bit off from 6500k standard.

So If I want better contrast ratio, I’m forced to use 6000K?

• This reply was modified 6 years ago by mds83.

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[Vincent]

However, I get a better contrast ratio by using the “as measured” at whitepoint.  But its at 6000k.  Thats a bit off from 6500k standard.

As long as its “white” (no pink, no green) it should look OK even it’s a bit warmer.

So If I want better contrast ratio, I’m forced to use 6000K?

 

This applies to all displays. Maximum contrast happens at its native whitepoint (“true native”, without any factory preset or correction).

BTW you posted an after calibration report. Some calibration options may decrease CR because these options may try to correct white and black point with graphic card LUT calibration (“profile info” > “calibration curves” will give info on that subject).

If you want to take measurements like expained in my 1st reply, better use “Tools > Report > Uncalibrated screen report” in DisplayCAL. This way you’ll measure monitor status (hardware), without any GPU correction which may cause CR drop.

[mds83]

I deleted my calibration and reset the monitor to factory default with “user color” selected.

Heres the log for “uncalibrated screen report”

10:56:27,592 Report on uncalibrated display device
10:56:28,299 ——————————————————————————–
10:56:28,299 Command line:
10:56:28,299 C:\Argyll_V2.0.0\bin\dispcal.exe
10:56:28,299 -v2
10:56:28,299 -d1
10:56:28,299 -c1
10:56:28,301 -yn
10:56:28,301 “-P0.49950347567,0.498881431767,1.12345679012”
10:56:28,301 -R
10:56:28,301
10:56:28,740 DisplayCAL: Starting interaction with subprocess
10:56:28,740 Setting up the instrument
10:56:29,703 Product Name: i1Display3
10:56:29,703 Serial Number: I1-15.B-02.234706.12
10:56:29,703 Firmware Version: v2.28
10:56:29,704 Firmware Date: 29Jan14
10:56:29,976 Place instrument on test window.
10:56:29,977 DisplayCAL: Waiting for send buffer
10:56:31,473 DisplayCAL: Skipping place instrument on screen message…
10:56:31,480 DisplayCAL: Sending buffer: ‘ ‘
10:56:31,482 Hit Esc or Q to give up, any other key to continue:
10:56:34,085 Measured display update delay of 27 msec, using delay of 136 msec & 0 msec inst
10:56:34,085 reaction
10:56:37,484 Patch 3 of 3
10:56:43,391 Patch 17 of 17
10:56:43,391 Uncalibrated response:
10:56:43,391 Black level = 0.4239 cd/m^2
10:56:43,391 50% level = 68.22 cd/m^2
10:56:43,392 White level = 323.53 cd/m^2
10:56:43,392 Aprox. gamma = 2.25
10:56:43,392 Contrast ratio = 763:1
10:56:43,392 White chromaticity coordinates 0.3201, 0.3425
10:56:43,394 White Correlated Color Temperature = 6057K, DE 2K to locus = 8.3
10:56:43,394 White Correlated Daylight Temperature = 6057K, DE 2K to locus = 4.5
10:56:43,394 White Visual Color Temperature = 5800K, DE 2K to locus = 8.1
10:56:43,394 White Visual Daylight Temperature = 5931K, DE 2K to locus = 4.3
10:56:43,394 Effective Video LUT entry depth seems to be 8 bits
10:56:43,394 The instrument can be removed from the screen.
10:56:43,562 DisplayCAL: Reached EOF (OK)

• This reply was modified 6 years ago by mds83.

[Vincent]

OK, it’s almost the same so GPU calibration was not doing something weird. ~750:1 seems to be native (and maximum) contrast ratio for yout unit.

IDNK nominal or advertised (by manufacturer) CR for that display. If your CR were significatively lower than advertised (not reviewed) you may want a return/exchange.

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