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Do you think Ryan's white clipping pattern would help you?
It's hard to say. Ryan's patterns are for 1000-nit masters, and will not resolve patch 723 (75.2%) and above. Looking at zoyd's tone mapping curves, 4000-nit masters can go all the way up to about 83%.
http://www.avsforum.com/forum/139-d...hdr-10-uhd-test-patterns-35.html#post55181272
I guess the ideal would be to have 2 calibrations - one for each mastering display
Yes, the question being whether we can achieve the higher clipping with the limited adjustability of the 5040UB.
I've added an HCFR feature request to have the current Near White scale made adaptive, to measure HDR clipping. For SDR, I find the Near White pattern easier to use than flashing clipping patterns.
 

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Discussion Starter #22 (Edited)
Just noticed my black is poor eg .11 nits. My env is a dark room with no ambient light. I see others have much better "black" eg Dominic has 0.019. What could be causing this? Possible light leakage within the projector or ? Because of this I have v poor contrast ratio, approx 1:1000.

Edit: Think that was with iris off. Will have to check what it is with iris on. Am I right in saying all calibration should be done with iris off, and then when calibration is complete turn it on? Dominic, you getting 0.019 with iris off?
 

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Think that was with iris off. Will have to check what it is with iris on. Am I right in saying all calibration should be done with iris off, and then when calibration is complete turn it on? Dominic, you getting 0.019 with iris off?
Yes and yes.
Try measuring with the meter facing the projector lens, diffuser on. This provides a more accurate measure of the contrast ratio, based on which you can deduce the black level nits.
 

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It's hard to say. Ryan's patterns are for 1000-nit masters, and will not resolve patch 723 (75.2%) and above. Looking at zoyd's tone mapping curves, 4000-nit masters can go all the way up to about 83%.
http://www.avsforum.com/forum/139-d...hdr-10-uhd-test-patterns-35.html#post55181272

Yes, the question being whether we can achieve the higher clipping with the limited adjustability of the 5040UB.
I've added an HCFR feature request to have the current Near White scale made adaptive, to measure HDR clipping. For SDR, I find the Near White pattern easier to use than flashing clipping patterns.
I believe he has added some support for 4000-nit masters. See the attached pattern. He has also added full grey scale patterns at 4000 and 10,000 nits. By the way, here is a link to another set of free HDR patterns. I haven't tried them yet. https://yadi.sk/d/RPrX2C7l3HEjPq
 

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ok, you can compare to this curve where I have shifted the knee parameter to give you ~50 nits at 50% stimulus. (actual 59 nits for 1000 nit master, 41 nits 4000 nit master)
Thanks for this Zoyd.

For some of us, hitting 59 nits at 50% stimulus won't be possible. It's a challenge in my case to even get to 50 nits. Is it possible to force both the 1,000 and 4,000 curves to hit 47 nits more precisely while maintaining the max luminance target of 141?
 

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Thanks for this Zoyd.

For some of us, hitting 59 nits at 50% stimulus won't be possible. It's a challenge in my case to even get to 50 nits. Is it possible to force both the 1,000 and 4,000 curves to hit 47 nits more precisely while maintaining the max luminance target of 141?
With 1000 nit master the lowest you can get the 50% value to go is about 58 nits. I'm adding the calculations to HCFR so you'll be able to do them on your own.
 

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With 1000 nit master the lowest you can get the 50% value to go is about 58 nits. I'm adding the calculations to HCFR so you'll be able to do them on your own.
Got it. I was afraid you might say that. ; )

Do you have an ETA for the next version of HCFR?
 

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Discussion Starter #30 (Edited)
Quick update, reset my BC profile to defaults, iris off, high lamp, left contrast at 50, brightness to 52, dialled in grayscale (peak of 148 nits), used Dominics method above to dial in luminance, then did my 50/50 sweep and calibration across the 6 colours using auto generated patterns casted via nvidia sheild. When done the picture looked terrible! Most colours blown. Spun up Ryans disk and put a 50/50 red pattern on the screen and it was seen that the colours calibrated using the generated patterns were miles off. Eg ryans 50/50 pattern was landing on the 75! HCFR was set to 2020/P3. Should HCFR (3.4.5.1) be sending the same patterns as Ryans eg when colour space is set to 2020/P3 eg 50 sat free measure and generated patterns is sending a 50/50 or actually is sending a 50/75? I'm thinking the later the way the colours are lining up.

Currently redoing the colours using Ryans disk. While I can dial in the hue and sat using the CIE digram, how will I dial in the 3rd dimension, brightness, as appears HCFR is off showing the delta luminance for that sat?
 

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Currently redoing the colours using Ryans disk. While I can dial in the hue and sat using the CIE digram, how will I dial in the 3rd dimension, brightness, as appears HCFR is off showing the delta luminance for that sat?
Hard to tell what you are doing but a couple of points with HDR calibration and HCFR:

1. You have to first calibrate to the PQ transfer function up to your clipping point, if you have done some sort of tone mapping, color calibration with a subset of BT.2020 won't work. All targets assume a raw PQ transfer function.

2. The sequences on the HDR disk that are currently supported at less than fully saturated BT.2020 primaries are in the HCFR flow section labeled:

a. P3 in BT2020 Color Sweep (pseudo-primaries scan at fully saturated P3 locations and 50% stimulus): Use the primaries/secondaries page for targets
b. P3 in BT2020 Color Sat Sweep (50% stimulus at P3 saturations from 0% (white) to 100% in 25% steps): Use the saturation sweeps pages for targets

Choose Color space BT.2020/P3 and check SMTPE HDR transfer function

The internal generator should give you the same results within 1 dE00 due to some rounding issues I'm currently fixing and assuming no additional errors coming from your video card vs. the Blu-ray player.
 

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Discussion Starter #32
Hard to tell what you are doing but a couple of points with HDR calibration and HCFR:

1. You have to first calibrate to the PQ transfer function up to your clipping point, if you have done some sort of tone mapping, color calibration with a subset of BT.2020 won't work. All targets assume a raw PQ transfer function.
Would you happen to be referring to where you have created new curves for Dominic as have used his method? Please forgive me on some of the technical terms as new to calibration but is adjusting the gamma known as tone mapping as I have adjusted the gamma prior to calibrating the primary and secondarys

Is the order different for HDR than SDR? When I did SDR, I did the following order of calibration steps; brightness, contrast, 2 point grayscale, gamma, primary and secondary saturations.
 

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Would you happen to be referring to where you have created new curves for Dominic as have used his method? Please forgive me on some of the technical terms as new to calibration but is adjusting the gamma known as tone mapping as I have adjusted the gamma prior to calibrating the primary and secondarys
Gamma is not a useful parameter in HDR calibration because the standard is based on absolute luminance, and is no longer a fixed power law function. The current standard for the HDR transfer function is SMPTE 2084 (sometimes referred to as "PQ"). Because the mastering display and user display may have different peak luminances there are work arounds (tone mapping) but for calibration purposes you align your display with the PQ function as close as you can. You can think of tone mapping like dynamic contrast where you turn it off for calibration and then turn it back on after.

Is the order different for HDR than SDR? When I did SDR, I did the following order of calibration steps; brightness, contrast, 2 point grayscale, gamma, primary and secondary saturations.
That's still the flow, just replace "gamma" with "adjust luminance response to follow the SMPTE 2084 curve up to your peak luminance" after disabling any additional tone mapping. At this point you would re-enable the displays internal tone mapping (in the case of a display like the LG OLEDs) or apply your own fixed tone map like the ones Dominic has been playing with.
 

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Discussion Starter #34
Sorry I was actually doing that, in that, adjusting the gamma on the projector but checking it against the luminance view in HCFR.
 

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Sounds right, if you could attach a zipped .chc file from a session with the disk that has a grayscale run and a BT2020/P3 run (using sequence 2a from above), I'll take a look.
 

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Discussion Starter #36
So just to spell it out essentially, the order for HDR is...

brightness, contrast, 2 point grayscale, luminance (adjusting gamma controls on projector), then disable gamma changes, primary and secondary saturations, re-enable gamma changes?
 

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Quick update, reset my BC profile to defaults, iris off, high lamp, left contrast at 50, brightness to 52, dialled in grayscale (peak of 148 nits), used Dominics method above to dial in luminance, then did my 50/50 sweep and calibration across the 6 colours using auto generated patterns casted via nvidia sheild. When done the picture looked terrible! Most colours blown. Spun up Ryans disk and put a 50/50 red pattern on the screen and it was seen that the colours calibrated using the generated patterns were miles off. Eg ryans 50/50 pattern was landing on the 75! HCFR was set to 2020/P3. Should HCFR (3.4.5.1) be sending the same patterns as Ryans eg when colour space is set to 2020/P3 eg 50 sat free measure and generated patterns is sending a 50/50 or actually is sending a 50/75? I'm thinking the later the way the colours are lining up.

Currently redoing the colours using Ryans disk. While I can dial in the hue and sat using the CIE digram, how will I dial in the 3rd dimension, brightness, as appears HCFR is off showing the delta luminance for that sat?
I think you may have already tried this without success, but I was able to get all colors to a Delta E of 5 or less by using the 50/50 2020 patterns (not the P3 setting). Colors look great when viewing HDR content. Not sure if its worth another shot...?
 

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Discussion Starter #38
I think you may have already tried this without success, but I was able to get all colors to a Delta E of 5 or less by using the 50/50 2020 patterns (not the P3 setting). Colors look great when viewing HDR content. Not sure if its worth another shot...?
ryans patterns or the auto patterns?

Until today, I was always using Ryans patterns against 2020/P3 but its a v slow process hence I tried the auto patterns casted as its a much faster process.
 

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Color Uniformity

5040UB owners, this might be a bit off topic but I am finding it important as I try to tackle HDR calibration.

When I did my SDR calibration, I noticed that the color uniformity was a bit off (greener on the right side and redder on the left side). I was able to use the color uniformity adjustments and my meter to get it reasonably balanced. I have read about people returning their projector 3-4 times with this issue so I decided to make it work. Overall my SDR calibration went very well despite this issue.

Now as I pursue HDR calibration, I am noticing that as I use brighter modes, the uniformity issue is more pronounced. And I cannot have two saved adjustment settings. So I am considering asking for a replacement.

This is my first projector, so I am not sure what I should be expecting. When you put up a full white screen, do you get a high degree of uniformity? If I don't, is my unit faulty or is this to be expected?

And by the way, the adjustment allows one to adjust the entire panel. So if you are getting an overall green skew you can use this to reduce the skew. I think this should be used as a last resort after adjusting gain / offset etc. but it could come in handy.
 
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