[kamui]

I've attached the chc. file of my HCFR HDR calibration attempt.

I've previously calibrated SDR and got superb results, but without changing any settings, this is what I get when I do an HDR run using Mehanik HDR test patterns, HCFR, and an i1Display Pro.

Everything is so far off of targets and I don't understand where to move forward from here.

I'd really appreciate any assistance in understanding what I'm looking at and why it looks so horrid!

 

[Dominic Chan]

I've attached the chc. file of my HCFR HDR calibration attempt.

I've previously calibrated SDR and got superb results, but without changing any settings, this is what I get when I do an HDR run using Mehanik HDR test patterns, HCFR, and an i1Display Pro.

Everything is so far off of targets and I don't understand where to move forward from here.

I'd really appreciate any assistance in understanding what I'm looking at and why it looks so horrid!

Are the TV controls in their default settings? The EOTF does look very unusual.

 

[kamui]

I left the TV settings in the same position I achieved after calibrating SDR, but not at factory defaults.

The images look pretty good and don't seem anywhere as bad as the graphs would suggest, so it's really confusing me.

 

[Dominic Chan]

I left the TV settings in the same position I achieved after calibrating SDR, but not at factory defaults.

The images look pretty good and don't seem anywhere as bad as the graphs would suggest, so it's really confusing me.

Some TVs share the settings between SDR and HDR. Your HDR luminance levels are quite a bit higher than the standard PQ.

 

[kamui]

The controls are definitely the same between SDR and HDR (I've tested that).

My tv (TCL 55s425) has very poor maximum light output (I've only measured a maximum of around 220 cd/m2). Could that have something to do with it?

 

[Dominic Chan]

The controls are definitely the same between SDR and HDR (I've tested that).

My tv (TCL 55s425) has very poor maximum light output (I've only measured a maximum of around 220 cd/m2). Could that have something to do with it?

I don’t think so. The low and mid levels you measured are quite a bit higher than the target.

 

[kamui]

I thought my mid levels (especially 60%) were way below target (being very far down from the reference line) or am I reading it wrong?

 

[kamui]

I don’t think so. The low and mid levels you measured are quite a bit higher than the target.

I looked again and I think I see what you're talking about. My 30 through 50 percent is way above the reference (looking at the gamma chart), and then 60 percent takes a massive dive below the reference line. This is really strange to me and I can't figure out why it's reading like that.

 

[Dominic Chan]

I looked again and I think I see what you're talking about. My 30 through 50 percent is way above the reference (looking at the gamma chart), and then 60 percent takes a massive dive below the reference line. This is really strange to me and I can't figure out why it's reading like that.

The "massive dive" is because the TV shows a very gradual tone mapping curve curve extending all the way to 10,000 nits (100%). Most displays have tone mapping that clips at about 75% (1000 nits) or 90% (4000 nits).

 

[kamui]

I'm not sure how to relate that information to the chart.

Should I only be worrying about the 50% and below and ignore everything above because it won't be able to graph properly? I apologise for my ignorance.

 

[Dominic Chan]

I'm not sure how to relate that information to the chart.

Should I only be worrying about the 50% and below and ignore everything above because it won't be able to graph properly? I apologise for my ignorance.

50% and below is where the “Normal” contents are. Above that are the highlights.

 

[kamui]

50% and below is where the “Normal” contents are. Above that are the highlights.

Taking what you said here, I tried re-calibrating the HDR and this is the best I could seem to do.

I tried to get up to 50% as close as I could to the EOTF luminance.

Is this progress in the correct direction?

I've included both my SDR and HDR calibrations for comparison to see if there's anything there that might help understand if I'm messing something up.

 

[Dominic Chan]

Taking what you said here, I tried re-calibrating the HDR and this is the best I could seem to do.

I tried to get up to 50% as close as I could to the EOTF luminance.

Is this progress in the correct direction?

I've included both my SDR and HDR calibrations for comparison to see if there's anything there that might help understand if I'm messing something up.

What changes did you make? Did they mess up SDR given that the calibrations are shared?

You should turn on "Override Targets" and "BT.2390". The RGB levels are actually not too bad.

 

[kamui]

After trying a LOT of different settings and ideas, I realized the only changes I could make without affecting the SDR calibration was the basic controls (contrast, backlight, and color) and a setting in the phone app for gamma (I can select a gamma setting of 1.8, 2.0, 2.2, or 2.4), even though as I understand it, that shouldn't matter with HDR, but changing the gamma preset drastically changed the EOTF luminance levels.

I have my SDR calibration gamma setting at 2.4 and the HDR gamma setting at 2.2.

I can't change the 11 point grayscale or CMS settings as you surmised because that would change the HDR as well.

I'm guessing this might be the best I can do. I'm just getting hung up on the HDR graphs because they look so far off from the reference lines.

 

[kamui]

Oh! I just saw the image you attached. Yeah that doesn't look as bad to me!

I'll try turning on those settings when I get home.

Also, I would quote you but there doesn't seem to be an option for that when I use my phone, only when I'm on my laptop