How do I make sure LR is recognizing my display's full HDR range?

[Brett J Deriso]

I just hooked up a new OLED that has a comparable brightness to my MacBook Pro's display, yet I only see approximately 1 additional f-stop worth of Dynamic Range on the right side of the Histogram divider with HDR editing turned on.  The remainder of the HDR half of the histogram is greyed-out.

This doesn't seem right to me.

How does LR know my display's capabilities? Is it taken from settings baked into the current monitor profile? I use a Calibrite Display Plus HL colorimeter to profile my displays, and I built this profile to target D65, 2.2 Gamma, and the display's measured luminance (i.e., I didn't try to match 120cd/m² --I simply cranked it all the way up and made sure "HDR" was turned on in the System Display Settings dialog).

Am I somehow choking LR's HDR capability with my calibration profile?

EDIT (to clarify solution):

So, I learned a lot of stuff about my external display, and about Apple's latest OS "improvements" that moved various settings around, as well as rediscovered their contempt for third-party peripherals, and I re-learned everything I knew about building ICC profiles. Here are the key takeaways:

1.  The Target Luminance value we traditionally set in an ICC profile is the maximum brightness level (in nits) for SDR content.  If your display is capable of additional nits above the target, that is what LR uses for Extended Dynamic Range.
2.  Set up the display in such a way that it is allowed to reach full brightness --for me (Aorus F032U2), that was "HDR - Game". Side note, for this particular OLED monitor, the baseline "HDR" mode disables the brightness control and caps the output at 500 nits. If you are setting up an external display, make sure it's giving both the maximum output and letting you attentuate that output with the display controls (you'll need this in #4).
3.  Calibrate the display using a colorimeter (I used the Calibrite Display Plus HL) with D65 as the target White Point, and 120 nits as the target luminance (or lower, if you prefer).
4.  Since you are telling the calibration software to build a profile maxing out the SDR luminance at an arbitrary level (120 nits, in this case), you will be prompted to measure the current luminance and adjust the brightness setting on the monitor before proceeding with the color swatches portion of the calibration.  Pull the brightness down with the display controls until you achieve a measured luminance as close to the target as possible, and -this is crucial- leave it there. From this point forward, if the display needs additional HDR headroom, and LR is set to edit in HDR mode, it will use this additional headroom to display it. So long as you...
5. Make sure to turn on "High Dynamic Range" in the system display settings dialog, or all of this is for naught.

[Ian Lyons]

Make sure that you have enabled HDR mode in Displays section of macOS System Settings

[Conrad_C]

In the screen shot, Built-in Display is selected, so the Reference Mode preset applies to the Built-in Display, not to any external displays such as the external OLED being asked about.

In fact — and I need someone to correct me if I’m wrong about this — I believe the Reference Mode presets apply only to Apple displays that support them (so, not even all Apple displays), and never apply to any non-Apple displays.

Finally, just for completeness, what enables HDR on an Apple display that supports it (such as the XDR display in the 14"/16" MacBook Pro) is not the Reference Mode preset exactly, but more specifically, if that preset has HDR enabled in it. So, HDR on an Apple XDR display can also be enabled by your own custom Reference Mode preset if you created it with HDR enabled. But again…I do not think this info is relevant when discussing any non-Apple display.

[JohanElzenga]

In fact — and I need someone to correct me if I’m wrong about this — I believe the Reference Mode presets apply only to Apple displays that support them (so, not even all Apple displays), and never apply to any non-Apple displays.

By @Conrad_C

I am pretty sure that you are correct.

[Brett J Deriso]

YES!  This completely threw me... I've just spent an hour over at ArtIsRight's YouTube Channel, educating myself on these new Reference Presets.  I was tearing my hair out, looking for the "Enable HDR" option on the MBP's built-in display, only to find it six levels deep in the "Preset" fine-tuning options.

Interesting that the upper limit for HDR if you're starting from the Photography (P3-D65) preset is 500 nits.  You can't force it to 1600 even if you wanted to.

I gather this means the Apple XDR Display (P3-1600 nits) preset, which is enabled out of the box, is meant to put full control of the display brightness in the user's hands with the F1 & F2 Keys, as well as the slider in Control Panel. Any other configuration where you set SDR and HDR upper limits is meant to lock out accidental changes or prevent adaptive nonsense like ambient compensation and "True Tone" from screwing with your color grading session.  All very smart and welcome features, now that I know where Apple is hiding them all.

[Ian Lyons]

I should also have mentioned that not all images will use the full histogram. I've attached a screenshot showing the histogram for an image that only extends about 1 stop into the HDR range.

The top histogram shows the HDR range in red to indicate that the display in not in HDR mode or is not capable of displaying HDR. The lower histogram indicates that display HDR mode is ON and display is also displaying HDR data.

[JohanElzenga]

Is that profile produced according to the Display Plus HL manual? You may indeed have choked Lightroom with it. On my MBP, the brightness slider of System Settings > Displays is somewhere in the middle if I choose Apple XDR Display P3-1600 nits. If I crank it up all the way to the right, then Lightroom no longer shows 4 stops of HDR, but less than two stops.

[Brett J Deriso]

You are absolutely right!  I just confirmed this using the "Apple XDR Display (P3-1600 nits)" preset. I guess that's Apple's word for profile --whatever.

I can feed LR an image I know has full details in the highlights, but under this profile, the only time LR shows the entire available right side of the histo is when I pull the display brightness down to about 48%, as you said.  It's even animated, so you can see the effect in real time.  When I crank the brightness all the way up, the histo clips again.

It seems paradoxical to me that if you push the display brightness up, the HDR portion of the histo shrinks, but that might be beacuse I'm conflating screen brightness with HDR headroom.  In fact, it's just the opposite. LR is saying, "as long as you pull the brightness of the display all the way down to 120cd/m², I will use everything above that for the HDR headroom. When you crank the whole display all the way up, you leave me no room for growth."

This is confirmed by the fact that all the other presets (or profiles) in the Display settings dialog that have a fixed luminance value disable the brightness controls on F1 & F2, and in the control widgets pulldown. I take this to mean the luminance target you use in a profile is supposed to represent the ceiling for SDR. The MacBook Pro's screen is perfectly capable of wildly exceeding 120cd/m², but will only do so with such a profile applied if you feed it content that intentionally exceeds the defined profile luminance.

So now I have to go back and revisit my profiling arrangement.

On a separate note, I've learned that the Aorus monitor I bought has predefined "Picutre Modes" (UGH!) like "Vivid", "Cinema", "FPS", and other such B.S. you expect to find on televisions and hardware purpose-built for gamers. Long story short, the only mode on that display that taps the full 1,000 nits available is "Vivid", and even then, you have to disable a bunch of other proprietary OLED burn-in protections to make sure their good intentions aren't undercutting your efforts.

[JohanElzenga · Accepted solution]

Actually, it is logical. If you crank the screen brightness all the way up, then you decrease the headroom that HDR uses. Your SDR highlights will already be (almost) the maximum brightness of the screen, so there is no extra headroom for HDR highlights.

[Conrad_C]

You are absolutely right!  I just confirmed this using the "Apple XDR Display (P3-1600 nits)" preset. I guess that's Apple's word for profile --whatever.

By @Brett J Deriso

FYI - No, the Reference Mode presets aren’t the same as ICC display profiles, although they work together with them. The Apple display Reference Mode presets works similarly to the hardware presets you find in pro color displays that support hardware calibration, such as the Eizo ColorEdge series, NEC SpectraView series, Asus ProArt series, and BenQ SW & PD series.

Apple created Reference Mode presets for the same reason those third parties were doing it long before Apple: ICC profiles can’t do everything. Because hardware-based presets can address the display hardware to control things like luminance range and color gamut limiting.

[Brett J Deriso]

Yep, yep, yep!  Just figured this out, too.  I'm a few steps behind, but I catch on quick, LOL.

Ye Olde ColorSync Utility shows that a specific ICC profile can be assigned to a preset, or reset to the one applied from the factory.

This still follows for non-Apple displays, and I can see the exact .icc file I created with Calibrite assigned to the AORUS.