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post #31 of 1125 Old 11-26-2017, 03:12 PM
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Originally Posted by viperlogic View Post

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.

Last edited by zoyd; 11-26-2017 at 03:22 PM.
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post #32 of 1125 Old 11-26-2017, 03:37 PM - Thread Starter
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Originally Posted by zoyd View Post
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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post #33 of 1125 Old 11-26-2017, 03:56 PM
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Originally Posted by viperlogic View Post
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.

Quote:
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.

Last edited by zoyd; 11-26-2017 at 04:00 PM.
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post #34 of 1125 Old 11-26-2017, 04:08 PM - Thread Starter
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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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post #35 of 1125 Old 11-26-2017, 04:13 PM
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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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post #36 of 1125 Old 11-26-2017, 04:16 PM - Thread Starter
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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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post #37 of 1125 Old 11-26-2017, 04:20 PM
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Quote:
Originally Posted by viperlogic View Post
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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post #38 of 1125 Old 11-26-2017, 04:24 PM - Thread Starter
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Originally Posted by jwhn View Post
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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post #39 of 1125 Old 11-26-2017, 04:29 PM
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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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post #41 of 1125 Old 11-26-2017, 04:36 PM
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Quote:
Originally Posted by viperlogic View Post
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.
I used Ryan's patterns, also with the Nvidia Shield. I measured some errors between the auto patterns and the shield (probably caused by my laptop) so I tend to use his patterns.
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post #42 of 1125 Old 11-26-2017, 05:08 PM
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Quote:
Originally Posted by viperlogic View Post
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?
I'm new to HDR calibration myself, but the way I understand zoyd's procedure is that you do not disable the gamma changes prior to adjusting primary and secondary satuations; on the contrary, you should adjust the EOTF to match ST.2084 (the first column in zoyd's tables) as closely as possible, adjust the colours, then re-adjust the tone curve according to the second column (for 1000-nit master) or third column (for 4000-bit master).
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post #43 of 1125 Old 11-26-2017, 05:14 PM
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correct, adjust first to ST.2084 and use that function as a baseline for color adjustments, as this is the target that all patterns use for HDR10 calibration. After that apply any tone mapping to try and capture additional highlights (at the expense of absolute color accuracy if your adjustments affect diffuse white and below range).

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Quote:
Originally Posted by zoyd View Post
correct, adjust first to ST.2084 and use that function as a baseline for color adjustments, as this is the target that all patterns use for HDR10 calibration. After that apply any tone mapping to move to try and capture additional highlights (at the expense of absolute color accuracy if your adjustments affect diffuse white and below range).
Dominic, would you mind putting that in Epson 5040 terms? Adjusting the epson gamma controls while checking against the luminance graph is that "adjusting to ST.2084"? If so, what is then tone mapping?

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post #45 of 1125 Old 11-26-2017, 05:47 PM
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Quote:
Originally Posted by zoyd View Post
correct, adjust first to ST.2084 and use that function as a baseline for color adjustments, as this is the target that all patterns use for HDR10 calibration. After that apply any tone mapping to try and capture additional highlights (at the expense of absolute color accuracy if your adjustments affect diffuse white and below range).
for the first step, adjusting to 2084, do you mean try to hit the absolute targets, up to 10,000 nits?
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post #46 of 1125 Old 11-26-2017, 05:49 PM
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Quote:
Originally Posted by viperlogic View Post
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?
Thanks for pointing me here from the owner's thread, Viperlogic! I'll try to restate my question here. Are you trying to calibrate HDR using Rec2020 color space in HCFR with the projector set to Bright Cinema color mode? My understanding is that only the Digital Cinema color mode of the 5040/6040 engages the cinema filter to enable the wider color gamut. I would think if you are using the Rec2020 color space in HCFR but then setting the projector to where it can attain only the standard REC 709 color space, it would be impossible to dial in the colors, especially the green. Keep in mind that I'm totally new to calibrating these projectors and using HCFR, so please correct me if I'm wrong.
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post #47 of 1125 Old 11-26-2017, 05:58 PM
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Originally Posted by seplant View Post
Thanks for pointing me here from the owner's thread, Viperlogic! I'll try to restate my question here. Are you trying to calibrate HDR using Rec2020 color space in HCFR with the projector set to Bright Cinema color mode? My understanding is that only the Digital Cinema color mode of the 5040/6040 engages the cinema filter to enable the wider color gamut. I would think if you are using the Rec2020 color space in HCFR but then setting the projector to where it can attain only the standard REC 709 color space, it would be impossible to dial in the colors, especially the green. Keep in mind that I'm totally new to calibrating these projectors and using HCFR, so please correct me if I'm wrong.
Check out this post...

https://www.avsforum.com/forum/68-dig...l#post55162546
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post #48 of 1125 Old 11-26-2017, 06:00 PM
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Originally Posted by jwhn View Post
for the first step, adjusting to 2084, do you mean try to hit the absolute targets, up to 10,000 nits?
Follow the absolute targets up to the point where your projector clips.

Quote:
Originally Posted by seplant View Post
Thanks for pointing me here from the owner's thread, Viperlogic! I'll try to restate my question here. Are you trying to calibrate HDR using Rec2020 color space in HCFR with the projector set to Bright Cinema color mode? My understanding is that only the Digital Cinema color mode of the 5040/6040 engages the cinema filter to enable the wider color gamut. I would think if you are using the Rec2020 color space in HCFR but then setting the projector to where it can attain only the standard REC 709 color space, it would be impossible to dial in the colors, especially the green. Keep in mind that I'm totally new to calibrating these projectors and using HCFR, so please correct me if I'm wrong.
That's right, the projector needs to be in Rec2020 mode with largest gamut possible (hopefully that's close to P3 primaries) and HCFR set to BT2020/P3
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post #49 of 1125 Old 11-26-2017, 06:19 PM
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Originally Posted by zoyd View Post
That's right, the projector needs to be in Rec2020 mode with largest gamut possible (hopefully that's close to P3 primaries) and HCFR set to BT2020/P3
The problem with projectors is that they are very bright for SDR but not so much by HDR standard. If you put them in the widest gamut mode (Digital Cinema) the brightest takes another big hit.
It’s a matter of trade off, common to all projectors when it comes to HDR.
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post #50 of 1125 Old 11-26-2017, 06:25 PM
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Quote:
Originally Posted by seplant View Post
I would think if you are using the Rec2020 color space in HCFR but then setting the projector to where it can attain only the standard REC 709 color space, it would be impossible to dial in the colors, especially the green. Keep in mind that I'm totally new to calibrating these projectors and using HCFR, so please correct me if I'm wrong.
The Cinema and Bright Cinema modes are actually wider than Rec709; Natural is Rec709.
They still can’t hit P3, hence the reason for using 50% or 75% saturation when dialing in the colors.
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post #51 of 1125 Old 11-26-2017, 06:36 PM
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Originally Posted by zoyd View Post
Follow the absolute targets up to the point where your projector clips.
Okay, and just to make sure I'm tracking, its going to be very tough for projectors to get even close to this, even starting at 20%/30% in my case. So just trying to understand the practical usefulness of this approach.

In the attached graphic, I am pretty much pushing my gamma all the way as it is. As you can see, my poor projector has no chance of following 2084 even starting at 30%.

Is this still the recommended approach?
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post #52 of 1125 Old 11-26-2017, 07:01 PM
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Originally Posted by jwhn View Post
Okay, and just to make sure I'm tracking, its going to be very tough for projectors to get even close to this, even starting at 20%/30% in my case. So just trying to understand the practical usefulness of this approach.

In the attached graphic, I am pretty much pushing my gamma all the way as it is. As you can see, my poor projector has no chance of following 2084 even starting at 30%.

Is this still the recommended approach?
Looks pretty bleak for accurate color reproduction, although the BT.2084 curve doesn't look right...should be 92 nits at 50% stimulus.
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Originally Posted by zoyd View Post
Looks pretty bleak for accurate color reproduction, although the BT.2084 curve doesn't look right...should be 92 nits at 50% stimulus.
Well I was able to get low errors against 2020. And with these settings its the best I've been able to get HDR content to look so far. So there's hope!

And you are right on the graph- it's just my labels off. Should be shifted over one. So 40% is actually 50%.

EDIT: I updated the graph so as to not confuse anyone. ; )

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Well I was able to get low errors against 2020. And with these settings its the best I've been able to get HDR content to look so far. So there's hope!

And you are right on the graph- it's just my labels off. Should be shifted over one. So 40% is actually 50%.
To try out zoyd’s approach, you can push the Contrast control up to match ST2084 up to 50%, adjust colors, then re-adjust the EOTF to one of the rounded curves.
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post #55 of 1125 Old 11-26-2017, 07:30 PM
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Originally Posted by Dominic Chan View Post
To try out zoyd’s approach, you can push the Contrast control up to match ST2084 up to 50%, adjust colors, then re-adjust the EOTF to one of the rounded curves.
Okay, will try that. I did put up the contrast and take down that last gamma setting as you had done. Gets to a similar place but I will keep playing with this.
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Originally Posted by viperlogic View Post
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.
One thing to check - are you starting by measuring a grey 50/50 pattern before doing the primary and secondaries?
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post #57 of 1125 Old 11-27-2017, 12:51 AM - Thread Starter
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One thing to check - are you starting by measuring a grey 50/50 pattern before doing the primary and secondaries?
Will have to check again as can't remember! Changed alot last night!

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post #58 of 1125 Old 11-27-2017, 02:48 AM - Thread Starter
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Originally Posted by Dominic Chan View Post
I'm new to HDR calibration myself, but the way I understand zoyd's procedure is that you do not disable the gamma changes prior to adjusting primary and secondary satuations; on the contrary, you should adjust the EOTF to match ST.2084 (the first column in zoyd's tables) as closely as possible, adjust the colours, then re-adjust the tone curve according to the second column (for 1000-nit master) or third column (for 4000-bit master).
Quote:
Originally Posted by zoyd View Post
correct, adjust first to ST.2084 and use that function as a baseline for color adjustments, as this is the target that all patterns use for HDR10 calibration. After that apply any tone mapping to try and capture additional highlights (at the expense of absolute color accuracy if your adjustments affect diffuse white and below range).
Quote:
Originally Posted by zoyd View Post
Follow the absolute targets up to the point where your projector clips.
This is where I'm getting lost, especially in terms of Epson controls, so please bear with me, is the st.2084 curve the white dotted line in the luminance view? When doing a 11 or 21 grayscale sweep it produces a yellow solid line. What Epson controls should be used to "match" the yellow solid line to the white dotted line, contrast or gamma? When you say match do you actually mean match the shape of it not its actual points?

If Epson gamma controls are being used then isnt that tone mapping and hence the two steps are the same thing of adjusting to ST.2084 and tone mapping?

If contrast is being used then at what should we set contrast to because for me with contrast at 50 up to level 642 flashes. If I want higher levels to flash then I have to reduce contrast eg contrast level 29 causes upto level 712 to flash.

I apologise if these seem"dumb" questions and I keep asking the same thing over but I'm struggling here, and I'm sure others are also.

Using Dominics steps (and contrast at 50 and near same gamma settings on Epson) as our max nits are nearly the same (141 vs 147), I get the following

Epson EH-TW7300, 104" borderless ReAct 3, Denon AVR-X2300W in 5.1.2, Monitor Audio Bronze, Monitor Audio Pro-65, BK P12-300 sub, Nvidia Shield, Vero 4K+, ATV 4K, Panasonic UB400, SKY Q, PS3, Wii, RPi, Sony XF90, Denon Heos soundbar, Amazon Echo, Logitech Harmony Elite

Last edited by viperlogic; 11-27-2017 at 03:02 AM.
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post #59 of 1125 Old 11-27-2017, 04:02 AM
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Yes, technically to calibrate you would set your contrast so that you see no flashing levels above 539 for 140 nits max luminance and adjust your 10 or 20 pt controls (if you have them) to match the shape of the white dotted line. The material was mastered to this line. If you can't clip at 539 then I would get 50% (502) as close to 92 nits as possible. Then you would adjust your color controls using patterns that are designed for 50% levels (92 nits). At that point you would back off on contrast and use 10/20 point controls to match one of modified curves (what we've been calling tone mapping), to bring back some of the highlights.
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post #60 of 1125 Old 11-27-2017, 04:19 AM - Thread Starter
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Quote:
Originally Posted by zoyd View Post
Yes, technically to calibrate you would set your contrast so that you see no flashing levels above 539 for 140 nits max luminance and adjust your 10 or 20 pt controls (if you have them) to match the shape of the white dotted line. The material was mastered to this line. If you can't clip at 539 then I would get 50% (502) as close to 92 nits as possible. Then you would adjust your color controls using patterns that are designed for 50% levels (92 nits). At that point you would back off on contrast and use 10/20 point controls to match one of modified curves (what we've been calling tone mapping), to bring back some of the highlights.
Unfortunately with the Epson 5040 we are very limited in our controls, we only have two point control of offset and gain for RGB. For gamma we have 9, known as colour tone 1-9. Then for colour we have hue, sat, and brightness for each of the RGBCYM colours

Epson EH-TW7300, 104" borderless ReAct 3, Denon AVR-X2300W in 5.1.2, Monitor Audio Bronze, Monitor Audio Pro-65, BK P12-300 sub, Nvidia Shield, Vero 4K+, ATV 4K, Panasonic UB400, SKY Q, PS3, Wii, RPi, Sony XF90, Denon Heos soundbar, Amazon Echo, Logitech Harmony Elite

Last edited by viperlogic; 11-27-2017 at 04:27 AM.
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