Wide Color Space Rec2020

Started by reddeercity, July 03, 2017, 09:11:16 AM

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reddeercity

After updating  my MP5.1 to mac OS Sierra 10.12.5 I started playing around with the new apple compressor  v.4.3.2  now supports wide color space .
Before the default color space was Rec709(HD1-1-1) or SD(BT601) now you have the option
of encoding to BT2020(Rec2020 9-1-9) and FCPX support wide color space , and no more clipping in the lows & highs
if you don't conform to HD space. This on the par with blackmagic resolve , autodesk smoke for mac or any other grading app.
I'm not even sure if Premiere Pro support wide color space , Just one more reason to transcode to ProRes 4444XQ Linear (Rec2020 Wide color space)  ;)


Compressor WideColor Space Rec2020
by RedDeerCityTV, on Flickr


Apple ProRes4444XQ WideColor Space Rec2020
by RedDeerCityTV, on Flickr

If you don't understand the differences between Rec2020 & Rec709 here is some help , Top image is rec2020 and the bottom is rec709
https://en.wikipedia.org/wiki/Rec._2020

https://en.wikipedia.org/wiki/Rec._709


Look at the black triangle there less information in rec709 image

reddeercity

One more thing , if you ever wondered what bit depth your video card/GPU is (or at least in mac OS Sierra 10.12.5)


10bit RGB Video GTX570 2.5GB Vram
by RedDeerCityTV, on Flickr

That's right 10bit RGB , I was doing a screen capture with a pass though to the HDSDI on my PC .

reddeercity

To continue down this road of color spaces --I have discover many things that need to be correct or accurate to be able to work in wide gamut (and rec/bt2020 is not the only wide gamut by the way) It's really important to have very good display that can reproduce the colors & gamma curve as I found out , I started my test by extracting my 10bit 2K mlv's with mlvfs --imported the virtual Cdng's in to A.E. CS6 --flatting them out to maximize the dynamic range (around 11.5 - 12 stops or so) --reduce the luminance to 16-235 (That was my mistake for wide gamut bt2020) I should have left the luminance linear or 0-255 , I used a sRGB display profile with 2.1 gamma  (so basically very close to HD-Rec709 but with more head room)

sRGB gamma 2.2


rec709 gamma 2.2


At the bottom of the curves you can the difference , why is this important you my ask ? If you working in different color spaces it well cause a big problem down the color grading pipe line . It will be more evident when switching to wide gamut where you need acute motioning in the right color space from start to finish .

That's all for tonight , I'll continue on with the next steps to have a fully wide gamut project in FCPX with Magic Lantern MLV Raw in ProRes 4444XQ Rec2020 color space --stay tune there a lot to explain for a trouble free multiply color space export (rec709 & rec2020) with out loosen image quantity or introducing corruption .

ItsMeLenny

Isn't both 601 and 709 a reduced luminance? 16 to 235 with chroma being 16 to 240.

reddeercity

Yes for broadcast e.g. ntsc , pal but also can linear with full range e.g. camera capture thought sdi (depends on camera of course).

reddeercity

Next I'll talk about the "Display P3" color space in Apple --why? will that's one of the new Wide Gamut color spaces (that is if you have a new MBP, iMac or late MP 2013 running Sierra)
it's a full range (0-255) 10bit RGB space as noted here , since there is limited wide gamut rec2020 monitors at a affordable  price there lots of wide gamut photo/p3 monitors that can be recalibrated

QuoteRecently, Apple has released new Mac and iOS devices with displays that support a
wider color gamut called Display P3.
QuoteDisplay P3 uses the same color gamut as DCI P3


So with FCPX to work in wide gamut you need to be in display P3 , even though you my have rec2020 color space files fcpx uses mac OS colorsync
QuoteFinal Cut Pro uses macOS ColorSync technology to match the known color space of
an image or video to the color space of an Apple display, according to the display's
ICC profile. This display profile can be set in the Displays pane of System Preferences.
To view the expanded color space in a wide-gamut project, you must use a P3 display.
When using an Apple P3 display, make sure the display profile in System Preferences >
Displays > Color is set to the default profile.
QuoteWhen you play wide-gamut source clips or photos from the timeline in Final Cut Pro,
the media is composited within the linearized Rec. 2020 working space (and will be
output, upon export, in the color space of the project setting). When sent to the monitor
for display, the clips are converted from project color space to the display profile with
ColorSync. On a P3 display, ColorSync will clip any colors outside of the P3 color space
to a value within the P3 color space. In real-world imagery, this clipping is rare, because
colors in nature aren't likely to exceed the values allowed in the P3 color space.


That explains why FCPX uses P3 for wide gamut , unless you have super hi detail close to clipping and in  log space P3 should be ok
but to Grade/Color Correct you will need a acute wide gamut corrected display.
In my next post I'll discuss the option to view the wide gamut video from FCPX timeline correctly for color correction & export in rec2020 & rec709