Inconsistent contrast ratio

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This topic contains 6 replies, has 2 voices, and was last updated by  thedandyman (@thedandyman) 4 days, 17 hours ago.

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  • #19208

    thedandyman (@thedandyman)
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    Hi,

    It’s my first time to calibrate/ profile my monitors using DisplayCal, so I hope you guys could help me out.

    As a background, I have a dual monitor setup – Asus PA279Q and Acer XB241H – I’ll focus mainly on the Asus monitor. I use a Spyder5 colorimeter. For what it’s worth, the colorimeter is around 5yo now, while both monitors are around 2yo.

    1. Before calibration, I tried generating a report and the contrast ratio was around 730+ (forgot the exact value).

    2. I then did a calibration/ profiling with the following settings – D65, gamma 2.2, white level 120 – and the contrast ratio dropped to 680+.

    3. A few weeks after, I tried it again but this time around everything is set to “as measured”, except for the white level, which was still set to 120. The contrast ratio went back up to 730.1.

    4. After a week, I tried to do it again. First, the same setting as #2. Right after that, the same setting as #3. Both had a similar contrast ratio, which is around – 741 and 743.

    I would get it if the results between #2 and #3 were different. But #4 did the same and the results were again different. So why is that?

    Also, I’m quite disappointed that the highest contrast ratio I was able to get is only 743. Is there any combination of settings I could use so it could increase further or is this a hardware problem (monitor, colorimeter, or both)?

    Lastly, I attached the measurement reports I generated for #4. Aside from the contrast ratio, is there anything else wrong/disappointing with the results?

    Note:

    • I did try generating several reports during each of the trials, and the contrast ratio is around the same (not exact though).
    • I tried calibrating/ profiling my Acer monitor and there was a drastic difference between the results – 730+ and 534.7. The setting was not the same for both though. Gamma was set to “as measured” in the first and 2.2 in the second.
    • For each of the trials, I did warm up my monitor and colorimeter for at least 30 minutes.
    • Mode used for the Asus monitor is “LCD RGB LED”. For the Acer, it’s “LCD White LED”.

    Thank you!

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    #19225

    Vincent (@vincent)
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    Max contrast ratio is at native whitepoint. If you correct WP in GPU or using monitor OSD you are limiting one or more channel max output, but since you are using a backlit panel the light leaked in black is the same… hence contrast drops the further you go from native whitepopint.

    GB-LED,  or more specific low cost GB-LED tend to hae a native white in cian-green side of whites if you know or are familiar with a CIE xy diagram. 100:1 drop from native white to D65 seems somehow expected.

    Regarding overall low contrast, it may be colorimeter’s fault. If you cand try with a Xrite i1d3 (i1displaypro, munki display).

    Regarding correction Spyder4/5 dit not have a custom correction for GB-LEDs, just old RGB LED from that old HP Dreamcolor. So you chose the right one given the limitations of the devices you own.

    i1Display Pro on Amazon  
    Disclosure: As an Amazon Associate I earn from qualifying purchases.

    #19253

    thedandyman (@thedandyman)
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    Thanks, @vincent !

    Just a couple of follow-ups though.

    1. If I want to stick with the native WP, does this mean that I just leave the WP setting to “as measured” AND don’t adjust the monitor gains when  the interactive display adjustment is shown? Are there any drawbacks when doing this, or will I still have good results?

    2. As I mentioned before, I tried calibrating my monitor using D65 + gamma 2.2 settings twice (on separate occasions) and the resulting contrast ratio had a considerable difference – 680:1 and 741:1. The same was true when I set the WP and gamma to “as measured” on two separate occassions as well. The first resulted to a 730:1 ratio, while the next was 743:1. Could this just be a Spyder5 issue or something else?

    #19254

    Vincent (@vincent)
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    Thanks, @vincent !

    Just a couple of follow-ups though.

    1. If I want to stick with the native WP, does this mean that I just leave the WP setting to “as measured” AND don’t adjust the monitor gains when  the interactive display adjustment is shown? Are there any drawbacks when doing this, or will I still have good results?

    There is a severe drawback… whitepoint will stay with native white color which usually is an ugly cyan-green white for GBLEDs.

    I would try whitepoint to be “white” at least: daylight curve but maybe cooler than D65.

    2. As I mentioned before, I tried calibrating my monitor using D65 + gamma 2.2 settings twice (on separate occasions) and the resulting contrast ratio had a considerable difference – 680:1 and 741:1. The same was true when I set the WP and gamma to “as measured” on two separate occassions as well. The first resulted to a 730:1 ratio, while the next was 743:1. Could this just be a Spyder5 issue or something else?

    They could be different OSD settings each time because warmup or other causes. IDNK what you did in OSD on each ocasion or monitor warmup time.
    Also we do not know it 680:1 is an actual contrast value, you’ll need a better device to confirm that.

    #19354

    thedandyman (@thedandyman)
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    Thanks again, @vincent.

    The thing is, I don’t know of anyone or any shop near me that has an i1d3 that I could borrow or rent. I’m considering buying my own but once I checked online, there’s a lot of discussion about an OEM and retail version. Is this still applicable to the latest version of the device? If so, would both version be compatible with DisplayCal?

    Lastly, with the i1d3, I would have to use a correction file instead of a specific mode, right? Should I use [LCD GB-r LED IPS (Dell U2413)], [LCD GB-r LED/RG Phosphor LED Family (AUO B156HW01 V.4, Dell U2413)], or something else?

    TIA

    #19372

    Vincent (@vincent)
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    PA279Q is a GB-LED so generic GB-LED bundled with DisplayCAL (U2413). Acer looks like a norma TN LED monitor so Generic W LED  or if there is a CCSS uploaded by cmminity for that Acer use it.

    Try a cooler white point (but “white”) first.

    #19437

    thedandyman (@thedandyman)
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    Got it!

    Any info though regarding the I1 Display Pro OEM and retail versions, are there still two versions being sold now? I’ve been reading that the retail version only works with the x-rite software but I’m not sure if that’s still applicable now. It doesn’t help that the old and new Q&As in Amazon/B&H regarding this are all mixed together.

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