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Hello there,
with all the new UHD HDR Blurays around I looked into the best way to play tese back on my JVC D-ILA RS40 (X3) Projector. I figured that “UHD Premium” is kind of a standard to be met. OK, checked it and the RS40 fulfills most of it (10 or 12 Bits input, bright, very good contrast, DCI color space) and for the resolution I don’t care, since I don’t even see the pixels at 1920×1080. So it seems that there is really no need yet for a hardware-upgrade for a lot of money right now.
I was surprised to find “90% of DCI-P3 color space” to be enough, but good for me. So doing this brings up some questions/issues:
(1) – First and worst, displaycal crashes, when trying to profile for bt202!
The error is: Division by zero Profiling for Rec.709 works fine.
How can I nail this down? Which file or log could I post? Might it just be the settings?(2) – Which setting are the correct ones? I want a kodi compatible 3D-LUT. I set my PJ to DCI color space and use the usual “tv-range input setting” (Kodi puts out tv-range as well). I use the preset “Video 3D LUT for madvr (D65, Rec. 2020 / SMPTE 2084)” with I guess needs a little tweaking and here I am unsure about the various options. I’ll mark the ones, where I am unsure.
(2a) DISPLAY and DEVICE (have it in German, don’t know the translations)
Everything here is clear to me.(2b) CALIBRATION
“Color temp” – 6500K? – Read about 5500 somewhere and 6500 elsewhere fpr bt2020.
“White luminance” – unsure here, value of what my PJ can output?
“Tone curve (Tonwertkurve)” – also unsure, Rec.1886?(2c) PROFILING
Seems clear to me.(2d) 3D LUT
“Peak luminace” – I think I read I should try some value around 400 here for PJ?
“Ref. luminance – leave at 0 / 10000 or tweak?
“Content color space” – DCI P3 or Rec.2020??!?!
“3D LUT format” – madvr, sure, but convert HDR to SDR? I guess NOT, right, PJ runs at 12 Bits input.Seems like this might be a longer journey again, but last time was well worth it. Got great help here, made my 3D LUT and forgot about the whole thing for a long time and enjoyed it. To get a glimpse, I just checked a UHD HDR file with the higher color space and some hand-tweaking of the PJs settings and already that looked quite promising…
Hi,
please attach your profile (“Create compressed archive…” next to “Settings” with the profile selected as well as the logs (“Create compressed archive…” on the log window).
Which setting are the correct ones? I want a kodi compatible 3D-LUT. I set my PJ to DCI color space and use the usual “tv-range input setting” (Kodi puts out tv-range as well). I use the preset “Video 3D LUT for madvr (D65, Rec. 2020 / SMPTE 2084)” with I guess needs a little tweaking
You can just use the madVR setting.
“Peak luminace” – I think I read I should try some value around 400 here for PJ?
That’s the default. Try it and see if you like it.
“Ref. luminance – leave at 0 / 10000 or tweak?
Depends on the actual content and how much you’re willing to clip. Leave at 10K if in doubt.
“Content color space” – DCI P3 or Rec.2020??!?!
All currently available HDR(10) content is P3 encoded within 2020, so leave at default (P3).
convert HDR to SDR?
Yes.
Hi Florian, thx. for the quick answer. I will upload the files hopefully tonight.
What does “Convert to SDR” exactly do? Compress back to 8 Bits? My PC and the PJ are connected at 12 Bits, the PJ calles it “Deep Color”. I was hoping I could save some of the dynamic range, since the PJ is pretty much within the specs of UHD Premium. 10-12 Bits and 1000 cd/m brightness with 0.05 cd/m black or 500 cd/m brightness with 0.0005 cd/m black. I am not sure about the black but the PJ is close to the 1000 cd/m brightness, since I have a high-gain Screen. Anyway the D-ILAs have enormous contrasts, so I guess the black should be well within that range, too.
What does “Convert to SDR” exactly do? Compress back to 8 Bits?
No, bitdepth is unrelated. It just needs to offer this option to match the separate 3D LUT slots in madVR.
Here is the profile as well as the log..
Another question: since I mesaure a projector, the cd/m” values are way off. Is this in any way taken into account?
Alright, this is a regression of changeset 4896, and it affects only devices with a black level of zero when trying to create a SMPTE 2084 3D LUT. It’s trivial to fix, already in SVN (from r5098 inclusive).
since I mesaure a projector, the cd/m2 values are way off
Not sure what you mean?
Ah, that is good news. So you will upload a new version soon? Not sure, how to get it quickly, since I am running arch linux and it might take a while until it hits the yaourt-repo. Well, maybe I can build it without installing it for the while..
I meant that the colorimeter is convinced that my screen has 40 cd/m², since it is rather far from the screen. If it expects 400, it will be very disappointing.
Ah, that is good news. So you will upload a new version soon?
Probably this week.
Not sure, how to get it quickly
It’s simple. See SVN checkout instructions under the source downloads in the documentation.
I meant that the colorimeter is convinced that my screen has 40 cd/m², since it is rather far from the screen. If it expects 400, it will be very disappointing.
Not necessarily. Factors of up to 10 for HDR and projection are common (meaning the adjusted SMPTE 2084 tone curve will assume a display that’s 10x brighter than what it actually is). You’ll have to see for youself. If it’s looking too dim, decrease mastering display white luminance, and then the display peak luminance setting on the 3D LUT tab (I wouldn’t go much below 200-250, otherwise you’ll loose most of the HDR effect).
OK, thank you! SS I guess I will just uninstall the arch package and go for the SVN all the way.
Since the PJ is known to be quite accurate without calibration already, I turned up the lamp, switched to DCI and made a LUT P3->Rec.2020 an checked it out.
WOW! – Very amazing colors with much more dynamics. Highlights are highlight and I could not spot any clipping. I am not even sure what I made there was right, but it looked very convincing. Very saturated but looking right that way and colorless scenes were just that. Impressive for a nearly 10 year old PJ design!
Looking forward
True, running from source is very straightforward. Downloaded it and measured and made a nice 3D-LUT. Very much enjoying the rich colors and contrast of the new media on my old equipment. 🙂
Thank you so much for this Florian!
I might come back with some questions when it comes to fine-tuning…
Back I am! 😉
Turning the Lamp up and using DCI colorspace on my PJ works great with Rec.2020 content.
To also be able to play back rec.709 content I would like to stay with these settings, so I don’t have to switch LUTs in Kodi AND switch PJ settings. So I made a LUT targetting Rec.709 and the colors are just fine but the overall brightness is a little too much. The picture looks kind of “hard” and grainy, no matter how clean and ungrainy the source. This is amplified by my screen as well, which is “high-gain”.
Any idea, how I could deal with that during creation of the LUT? The darker lamp mode always left me with a wish for just a little more light, anyway, so if I could compensate for the brightness I’d have a better picture on Rec.709 than before as well.
