SDR/BD2020 for my Projector - AVS Forum | Home Theater Discussions And Reviews
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post #1 of 4 Old 02-06-2020, 03:50 AM - Thread Starter
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SDR/BD2020 for my Projector

Hi,

I have a Sony VW285ES Native 4K projector that supports HDR though actual dynamic range is not actually high by today's direct view TV standards.

I recently purchased a Panasonic UB420 that can convert HDR for lower range displays and output SDR/BT2020.

My question is can I calibrate for SDR/BT2020 ?


I use a old laptop with HCFR and a i1D3 (also have a i1 pro spectro that I can use to profile the i1d3) I use the second HDMI output of the laptop and MadVR TPG.

I can set HCFR to use BT2020 as reference but I'm not sure my old laptop using RGB output is sending the right colors for calibrating primaries and secondaries. Maybe I should use some other method of displaying the primaries and secondaries ?...

When I tried this yesterday it was easy to set grey scale and get very good readings for colors except green which didn't respond to anything I did and remained at a Delta E of 5.8 no matter what I adjusted. I hadn't attempted any form of calibration is maybe a year so I think doing it over would result in getting it even better.

-Brian

Edit- Found some information about tone mapping with HCFR and so whatever I did yesterday after Grey Scale was wrong... For now I'll investigate using the advice I found in the Epson Projector Calibration thread.

Last edited by Brian Hampton; 02-06-2020 at 04:13 AM.
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post #2 of 4 Old 02-06-2020, 07:03 AM - Thread Starter
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Hello Again... (still me),

I updated my copy of HCFR and wow it's been improved since the version I last used.

I have started adapting some instructions from the Epson HDR calibration work in progress thread to make them useful for my particular setup.

The chain for me is Panasonic UB420 -> Denon AVR -> Sony VW285ES

I told the Panasonic player I use a projector and I want SDR/BT2020 output. (I believe I read this tone maps to a range of 200 Nits)

For calibration I use a laptop secondary HDMI output running in place of the UHD player. I use MadVR TPG and have easily adjusted grey scale. Something is wrong with my references settings in HCFR because I measure a gamma of 9 or so and that's very unusual so I'm still wrong about something in the HCFR settings.

My projector bulb after a thousand hours is still managing to output 28 FLbs or 85 Nits.

I'm in the process of altering these directions from the Epson HDR thread...

Pre-steps

- Using HCFR 3.5.1.4
- Set HCFR to 20 point (HCFR: Measures -> Parameters -> Number of grayscale levels)
- Set HCFR Colour Space to “UHDTV - Rec2020/P3” (HCFR: Advanced -> Preferences -> References)
- Set HCFR to SMPTE 2084 HDR (HCFR: Advanced -> Preferences -> References)

Grayscale
- Do 21 point grayscale sweep (HCFR: F2)
- Dial in using 30% and 80% points using continuous measure (HCFR: F8) and adjusting Red and Blue offset for 30% and Red and Blue gain for 80% so as to get a dE of 2 or lower, though lower than 1 should be easily achievable
- Note: 30% and 80% are typically used but you may get better results finding the best balance between 10/20/30 and 80/90/100.
- May take a few attempts as offset and gain affect each other

Tone Mapping:
- Enable tone mapping in HCFR by checking "BT.2390 Tone Mapping" and "Override Targets" (HCFR: Advanced -> Preferences -> References)
- Set "Diffuse White[nits]" to what you personally would like, one school of thought is set it to what you use for 100% for SDR movies eg somewhere between 20 or 40 nits, note the higher you go the less room you leave for specular highlights
- Set “Target MaxL” to your 100% measure from the grayscale run
- Set “Master MaxL” and “Content MaxL” to 1000 or 4000 depending on what majority of your content is or even do two separate calibrations
- View Luminance graph. Grey dashed line is the target, yellow solid line is measured from grayscale sweep.
- Do a grayscale run after changes

CMS

- In HCFR, in the Information window, change the dropdown from "Comments" to "CIE Chart"
- In HCFR, change view to "Primaries and Secondaries", select white and run continuous measure so we get a reading for 50% white aka Diffuse White (HCFR: F8)
- Change view to “Red Saturation Scale", select 50% saturation and run continuous measure (HCFR: F8)
- Dial in 50% saturation by using Hue (rotates the point around the center) and Saturation (moves it in and out from the center) so the yellow dot is in the second red box from the center of the chart.
- The third dimension, Brightness, cannot be done from the CIE Chart so adjust the CMS Brightness so "delta luminance" in the "Saturation colour" window is as close to 0% as possible for 50% saturation.
- Note, after adjusting brightness you may need to re-adjust CMS Hue and Saturation. This may take several attempts.
- Repeat for 50% Green, Blue, Cyan, Magenta, Yellow
- Run saturation sweep for all Primaries and Secondaries (HCFR: Measures -> Saturations -> Primary and Secondary colours)
- From the saturation sweep, 0%-25%-50%-75% saturations all should have a DE of less than 2. 100% saturations typically have a much higher DE as this projector, especially not having the cinema filter engaged, cant get the wider colour gamut. Green is the worst offender.
Post steps
- Check Grayscale, Tone Mapping and CMS again as adjustment to one can impact others
- Run a Full Tilt Boogie (HCFR: Measures -> Full Tilt Boogie)
- Save the HCFR chc file for future reference

Last edited by Brian Hampton; 02-06-2020 at 07:08 AM.
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post #3 of 4 Old 02-06-2020, 08:14 AM
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Quote:
Originally Posted by Brian Hampton View Post
I told the Panasonic player I use a projector and I want SDR/BT2020 output. (I believe I read this tone maps to a range of 200 Nits)

For calibration I use a laptop secondary HDMI output running in place of the UHD player. I use MadVR TPG and have easily adjusted grey scale. Something is wrong with my references settings in HCFR because I measure a gamma of 9 or so and that's very unusual so I'm still wrong about something in the HCFR settings.

My projector bulb after a thousand hours is still managing to output 28 FLbs or 85 Nits.

I'm in the process of altering these directions from the Epson HDR thread...

Pre-steps

- Using HCFR 3.5.1.4
- Set HCFR to 20 point (HCFR: Measures -> Parameters -> Number of grayscale levels)
- Set HCFR Colour Space to “UHDTV - Rec2020/P3” (HCFR: Advanced -> Preferences -> References)
- Set HCFR to SMPTE 2084 HDR (HCFR: Advanced -> Preferences -> References)
If you want to use Panasonic's SDR/BT2020 output then you should set HCFR accordingly - Gamma 2.2 or 2.4, rather than 2084 HDR
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post #4 of 4 Old 02-06-2020, 08:23 AM - Thread Starter
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Thank you...

I was adapting instructions from else where and knew gamma readings of 9 or so were bogus.

I will try again with this new info.
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