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Monitoring for High DynamicRange and Wide ColourMARCH 2017

Gord LangdonVideo Applications Engineer – Canadagord.langdon@tektronix.com

4K/UltraHD

• What’s more impressive?◦ High Dynamic Range◦ Wider Colour Gamut◦ Immersive Audio◦ High Frame Rate?

2

MORE PIXELS BUT WHO CARES?

4096

x216

0 4K

3840x2160 UHD

2048

x108

0 2K

1920x1080

1280x720

720x480720x576

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How Does Workflow Change for HDR & WCG?• Unprecedented demand for more content to more devices

creates new pain opportunities and challenges for us◦ ‘The trick is optimizing the content for every platform’◦ Camera Acquisition

▪ RAW, Log and LUTs◦ Post-Production and Delivery

▪ Colour grading, mastering

• Are ‘golden eyes’ and experience enough?

◦ What tools could help you to stay ahead of the curve?

3

How Does Workflow Change for HDR & WCG?

4

• In Production, how do you verify scene lighting,camera dynamic range (15 to 16 stops), specularhighlights, etc.?

• How do you determine the average light (18%grey) level in HDR capture (APL too high fordisplay)?

• In Post, how do you verify that the SDR colourgrade does not have a significantly different ‘look’than the HDR?

• How do you verify that the HDR delivery coding(PQ, HLG, Dolby Vision) is correct for the targetdevices?

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Colour Gamuts

Anatomy of the Eye’s Receptors• Rods

◦ Sensitive to blue-green light◦ Used for vision in dark/dim conditions

• Cones - 3 Types sensitive to:◦ long wavelengths (red)◦ medium wavelengths (green)◦ short wavelengths (blue)

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http://webvision.med.utah.edu/index.html

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Colour Models – CIE Chromatcity

7

BT709/sRGB(70% NTSC)~SMPTE C

BT2020

CIE-1931 chart

D65 white

NTSC(1953)

CIE-1976 chart(More perceptually uniform than CIE-1931)

D65 whiteBT2020

BT709/sRGB~SMPTE C

NTSC(1953)

• CIE xy chromaticity diagrams with 2 degree observer◦ Still foundation of most color models

Colour as a Volume

8

Sony

Black

White

Black

White

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Pointer’s Gamut• 1980 research by Michael R. Pointer

• Set of real-world colours that can be reproduced using subtractive color mixing◦ Only light that is reflected by an object, not emitted by the source◦ Diffuse not specular reflection

20 MARCH 2017 9

www.tftcentral.co.uk

ITU 601-7 & 709-5

601-7 525 CIE x CIE yRed 0.630 0.340Green 0.310 0.595Blue 0.155 0.070White 0.3127 0.3290

10

709-5/601 625 CIE x CIE yRed 0.640 0.330Green 0.300 0.600Blue 0.150 0.060White 0.3127 0.3290

ITU-R BT 709-5

ITU-R BT 601-7

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DCI P3

12

SMPTE

RP 431-2: 2011

XYZ P3 CIE 1931 x CIE 1931 yRed 0.680 0.320Green 0.265 0.690Blue 0.150 0.060

XYZ P3 CIE 1976 u CIE 1976 vRed 0.496 0.526Green 0.099 0.578Blue 0.175 0.158

ITU BT.2020-2

2020-2 CIE 1931 x CIE 1931 yRed 0.708 0.292Green 0.170 0.797Blue 0.131 0.046White 0.3127 0.3290

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2020-2 CIE 1976 u CIE 1976 vRed 0.557 0.517Green 0.056 0.587Blue 0.160 0.126White 0.3127 0.3290

ftcentral.co.uk

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ACES

ACES CIE 1931 x CIE 1931 yRed 0.7347 0.2653Green 0.0000 1.0000Blue 0.0001 -0.0770

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XYZ P3 CIE 1976 u CIE 1976 vRed 0.6234 0.5065Green 0.0000 0.6000Blue 0.0002 -0.3339

SMPTE

ST 2065-4:2013

Colour Difference Equations

15

SD 525/59.94/2:1 & 625/50/2:1Y = 0.299 R +0.587 G +0.114 BPb = 0.564 (B-Y)Pr = 0.713 (R-Y)

HD 1920x1080 & 1280x720 (ITU-R BT. 709)Y = 0.2126 R +0.7152 G +0.0722 BPb = [0.5/(1-0.0722)] (B-Y)Pr = [0.5/(1-0.2126)] (R-Y)

UHD1/2 3840x2160 & 7160x4320 (ITU-R BT. 2020)Y = 0.2627 R +0.6780 G +0.0593 BPb = (B-Y) /1.8814Pr = (R-Y) /14746

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Code Values for Colours• 4K can use Rec 709, DCI P3, or Rec 2020 with 10 or 12 bits

• SDI digital code values for RGB primaries are the same for all spaces◦ Translation between SDR and HDR will scale the colours

Dynamic Range -Background

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Visual Dynamic Range

18

20 NITS = 0 STOPS = 18% REFLECTANCE

Nits (cd/m^2)

Mesopic

PhotopicS

cotopic

Sony, AR

RI, C

anon~16-stops

PushPull

10^8

10^-6

10^6

10^4

10^2

10^0

10^-2

10^-4

(18%) 20

(5000 nits)8

(.08 nits) -8

6

4

2

-2

-4

(20nits) 0

-6

Stops

Adapted Eye~7-stops

Bright

adaptionD

arkadaption

(100nits)2.5

starlight

moonlight

indoorlighting

Sun lightoutdoor 24-stops w

ith some adaption

AdaptedEye

Bright

Adaption

Dark A

daption

7-stops

Sunlightoutdoor

IndoorLighting

Moonlight

Starlight

Nitere (Latin) = to shine, glitter, or look bright

OETF, EOTF and OOTF

OETF EOTF

Scene-ReferredImageData

CameraEncoding

DisplayDecoding

Opto-Optical Transfer Function

• Opto-Electrical Transfer Function◦ transforms scene luminance to

digital code values

BBC R&D

• Electro-Optical Transfer Function◦ transforms code values back to

displayed luminance

Display curve is NOT inverse of capture curve

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[NPM]^-1 [M]

2.4

LPF

delay

LPF

delay

cameratristimulus

0.45

gammaprecorrect

Y’, Pb’, Pr’encode

Y’, Pb’, Pr’decode

gammaof Display

[NPM]

tristimulusof Display

EOTF(BT.1886)

OETF(BT.709)

Filter &quantize

Filter &interpolate

Y’, Cb, Cr274M 4:2:2

Y’,Pb’,Pr’

[M]^-1

G’,B’,R’R,G,BIntegral to CRT’sgrid drive

Video OETF/EOTF for SDR

• BT.709 says camera output, V, is linear to 1.8% and then proportional to (light)0.45 above that◦ Lower gain (straight line) in the blacks mitigates camera noise (not needed with new cameras)

• ITU BT.1886 says TV monitor displayed Light = (V + offset)2.4 over entire range

• Note that 1/0.45 = 2.22 and not 2.4… OOTF system gamma is not unity!◦ Blacks are s t r e t c h e d to increase the full dynamic range

Gamma () Q&A◦ It is caused by the voltage to current grid-drive of the CRT (not the phosphor)

▪ CRT response follows a black-level sensitive power-law▫ Closely matches human vision brightness sensitivity▫ Luminance = (V + black-level)^gamma

▫ Room light or black-level adjustment dramatically changes gamma▫ Black-levels can track room lighting with auto-brightness since early ‘70s

◦ CRT gamma is fairly constant ~2.4 to 2.5, but what about flat panel displays?▪ BT.1886 says all displays should be calibrated to 2.4

◦ Why keep using gamma power-law?▪ Cameras do not need to be set for BT.709 gamma▪ Human Visual Response? Not needed if a display matches the scene▪ For SDR displays, even with WCG colorimetry, BT.1886 still applies

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Linear Camera(natural response)

LinearDisplay

Lightness perceptiononly important for S/Nconsiderations

RGB

If camera response were linear,>15-bits would be neededand MPEG & NTSC S/N fidelitywould need to be better than ~90 dB

Current driven CRTor linear flat-panel

display

D65 light source

Perception is1/3 power-law“cube-root”

~100 steps (butneed15 bits toshow the smallblack level steps)

NTSC & MPEG(8 bits crushes blacks)

Need to match light outputBut do not look the same!

Perceptuallyuniform steps

Image ReproductionIDEAL IF DISPLAY LIGHT PATTERN MATCHES SCENE

CRT response(BT.1886)

R’G’B’

D65 light source

Thanks to the CRT gamma, wecompress the signal to roughlymatch human perception and only7 bits is enough!

Need to match light output.Look the same with only 7-bits

8-bits

~100 steps (7-bits)

1 JND

1 JND

1 JND

Quantization andnoise appear

uniform due toinverse transform

Image ReproductionDISPLAYED IMAGE MATCHES SCENE WITH ONLY 7 BITS!

Perceptuallyuniform steps

Perception is1/3 power-law“cube-root”

Cameragamma

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0 0.5 1

0

0.5

1

Extended BT.709 Gamma Curve

gammaX Vk

Lstar Vk

100

Vk

0 0.5 1

0

0.5

1

CRT Gamma & System Curve

CRT Vk

gammaX Vk

gammaT Vk

Vk

System Gamma

• Legacy system gamma is about 1.2 to compensate for dark surround viewing conditions

• Amazing Coincidence!◦ CRT gamma curve (grid-drive) nearly matches human lightness response, so the pre-

corrected camera output is close to being ‘perceptually coded’◦ If CRT TVs had been designed with a linear response, we would have needed to invent

gamma correction anyway!

Camera pre-correction is

inverse gamma(0.45)

CRT gamma (2.4)compared to totalsystem gamma

(1.2)

BT.1886 displayLinear display

Why High Dynamic Range?HDR RETAINS BRIGHT SPECULAR HIGHLIGHTS AS WELL AS DETAIL IN BLACKSCOLOURS CAN APPEAR MORE SATURATED

Sky Light: >500K nitsDirect sunlight >1 billion nits(don’t look at it)

Laptop or TV: 100 to 200 nitsHard to see in bright daylight

Shadows: .1 to 10 nitsWith the day-adapted eye, shadows can be 10 nits;in a living room, less than 0.1 nits

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HDR for Camera Acquisition

Camera Acquisition

“We’d like to see what’s outside the window as well as what’s inside the room.”

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Camera RAW and Log• Shooting RAW

◦ Camera photosite sensor data before any processing▪ No white balance, ISO or colour adjustments▪ 12 to 16 bit depth▪ Not viewable directly on a monitor – must convert to video

▫ De-Bayering process combines brightness + colour → RGB

• Shooting Log◦ Maximizes captured sensor data using a logarithmic gamma curve

▪ Includes processing information▪ Video formats specific to camera manufacturers▪ Looks washed out on a monitor

▫ Use a Look Up Table (LUT) to transform for viewing

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De-Bayer

RGB

Log Gamma• Log gamma on modern cameras allows you to shoot a ‘flat’ image,

capturing more details in both highlights and shadows

• While a flat image may not look pleasing while on set, it providesmore freedom for colour grading in post-production

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709Log

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Capturing Camera Footage

• Setup your test chart withinthe scene

• Adjust the lighting to evenlyilluminate the chart

• Adjust the camera controls toset the levels◦ ISO/Gain, Iris, Shutter, White

Balance

SpecularHighlights 18% Grey

90% ReflectanceWhite

ReflectiveBlack

SuperBlack

Camera Log on 709 Waveform Monitor

mV on left % on right

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Camera Log – Code Values, Nits, %

Gamma

0% Black10-bit Code-

Value %18% Grey

(20 nits illumination)10-bit Code-Value

%90% Reflectance

White10-bit Code-Value

%

S-Log 90 3 394 37.7 636 65

S-Log2 90 3 347 32.3 582 59S-Log3 95 3.5 420 40.6 598 61

Log C Arri 134 3.5 400 38.4 569 58

C-Log Canon 128 7.3 351 32.8 614 63

V-Log Panasonic 128 7.3 433 42 602 61

Red Log 95 4 468 46 671 69

BMD Film 95 4 400 38 743 78

ACES (proxy) ND ND 426 41.3 524 55

BT.709 64 0 423 41.0 940 100

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HDR Camera Monitoring – LUT vs F-Stops

-8

+8

0

2.3(90%)100 nits

(18%) 20 nits

4525 nits

0.07 nits

HDR (16-stops)

HDR Live Scene - up to 16 stops(white clipped 8-bit BMP ~10 stops)

Log2 scale

Depends onCamera Format

Stop waveformIndependent ofCamera Format(SLog3 to Stop LUT)

S-Log3 to BT.709LUT

Raw S-Log3

FORMATS-Log3

HDR

SDR/HDR

Live Camera Interface(SDI / IP)

BT.709SLog1SLog2SLog3

Canon ClogARRI LogC

Custom

Studio Control RouterCamera Control

Reference Pix MonitorPortable Recorder

Etc.

0 200 400 600 80087

65

43

21

01

23

45

67

8F-stop Waveform (stop/Nit scale)

0

2.5

Fstop Iyi,L n

n

Tektronix WFM (aka Scope)

0 200 400 600 800100

0

100

200

300

400

500

600

700

800mV Waveform SLog3

0

700

Vmv Luma_Slog3_8b,L n

Vmv Iyi,L n

n

BT709 View LUT

The only commonreference for distinguishing

HDR from SDR is Light

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Simple LUT To Get Stops Waveform

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CONVERSION LUTS FOR CAMERAS COMPARED TO BT.709

0 200 400 600 800 10008

7

6

5

4

3

2

1

0

1

2

3

4

5

6

7

8Camera to f-stop (light), 0=18% refl

0

2.5LUT_Slog1_fstop

ia

LUT_Slog2_fstopia

LUT_Slog3_fstopia

LUT_BT709_fstopia

940420

ia10-bit Code Values

Stop values (0 = 20 nits, 18% reflection)

Waveform Graticule in Code Values and StopsDigital CodeValues on left

F-Stopson right

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HDR for Delivery

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HDR – Viewer Preferences

Dolby

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HDR EOTF for No Visible Banding – 10 or 12 bits?

• Dolby ‘Perceptual Quantizer’ curve◦ Efficient use of codewords

Dolby

• ‘Barten Ramp’◦ Contrast Sensitivity

versus Luminance

HDR EOTF for No Visible Banding – 10 or 12 bits?

• Maybe 10 bits are enough?

Dolby

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HDR Standards

SMPTE• ST 2084 – EOTF for Perceptual Quantization (PQ)

▪ Adopted from Dolby Vision

• ST 2086 – Static metadata for colour and dynamic range of the masteringdisplay

▪ E.g., DCI-P3 gamut, D65 white point, with max specular reflectance of 10k nits

• ST 2094 draft – Dynamic metadata Master Display Color Volume▪ Content-dependent metadata to enable compatibility with legacy displays▪ ~15% extra bandwidth for metadata distribution (in HEVC or AVC)

• SMPTE IMF – ST 2067-21 (App 2 Extended)▪ Can signal ST 2084 and carry ST 2086 metadata▪ Next step is a carrier for ST 2094 dynamic metadata

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SMPTE• SMPTE IMF – ST 2067-21 (App 2 Extended)

▪ Can signal ST 2084 and carry ST 2086 metadata▪ Next step is a carrier for ST 2094 dynamic metadata

• ST 352 SDI VPID –video payload identifier◦ Progressive/interlace, picture rate, sampling

structure, aspect ratio, bit-depth◦ Colorimetry, HDR mode◦ 4k/UHD quad-link 2SI or square-division mapping

CTA• HDR10 Media Profile

◦ Adopted by the Blu-ray Disc Association (BDA) for 4K Ultra HD◦ Based on ST 2084 PQ

▪ 10-bit, BT.2020 colour▪ Mastered over a range of 0.05 – 1000 nits (20,000:1)▪ Static metadata between source and display

▫ ST 2086 from mastering display▫ MaxFALL – Max Frame Average Light Level▫ MaxCLL – Max Content Light Level

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Dolby Vision• Licensed end-to-end solution based on ST-2084 PQ curve

◦ Mastered over a range of 0.0001 – 10,000 nits (1,000,000:1)▪ 12 bits, Rec 2020 colour

◦ DV-mastered content, played from a DV-capable source, sent to aDV-capable display

◦ Display includes a chip that identifies its output capabilities (lightoutput, colour space, etc.), which it passes as metadata back to thesource▪ Dynamic metadata is possible on a per frame or per scene basis▪ Base layer of SDR content encoded with a Gamma EOTF decodable by

any streaming video decoder▪ Enhancement layer metadata tells the DV decoder how to do SDR to HDR

conversion▫ Adds ~15% to the size of the bitstream

44

Hybrid Log-Gamma (HLG)• Hybrid Log-Gamma (from BBC/NHK)

◦ Seamless ‘gamma’ power-law processing in blackssimilar to BT.709 below 100 nits

◦ Extends log processing of high brightness peaksup to 3 stops to mitigate blown-out or clippedwhites

◦ Can be displayed unprocessed on an SDR screen▪ Does not require mastering metadata▪ EOTF adjusts system gamma to correct for viewing

environment (10 to 500 nits)◦ Good for both SDR & HDR live production

Wikipedia

• Standards• ARIB STD-B67(Japan)• ITU-R BT.2100 and DPP (UK) approved both HLG and ST-2084 PQ

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SDR vs PQ vs HLG• HLG has similar power-law gamma

to SDR in dark range, thenchanges to a log gamma above~14 nits

• PQ has more gain in dark rangebut is less compatible with BT.1886SDR

SDR HLG PQ

SL-HDR

• Jointly developed by Technicolor, Philips, STMicro, CableLabs

• Workflow to grade both HDR and SDR

• Backwards compatibility◦ metadata can reconstruct an HDR video from an SDR stream

▪ added to HEVC or AVC via SEI messages▪ ‘single layer’ video stream

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ETSI TS 103 433

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HDR – Evolving Consumer Standards• UHD Alliance

◦ SMPTE ST-2084 EOTF◦ Mastering:

▪ 100 percent of P3 colors must be displayed▪ HDR range >1,000 nits peak brightness and <0.03 nits for black

• UltraHD Premium™ TV branding specs◦ Either >1000 nits peak brightness and <0.05 nits black◦ OR >540 nits peak brightness and <0.0005 nits black

▪ More than a million to one ratio? How can you get that black?◦ At least 90% of DCI P3 colour space

HDR and WCG Challenges

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How Does Workflow Change for HDR & WCG?

50

• In Production, how do you verify scene lighting,camera dynamic range (15 to 16 stops), specularhighlights, etc.?

• How do you determine the average light (18%grey) level in HDR capture (APL too high fordisplay)?

• In Post, how do you verify that the SDR colourgrade does not have a significantly different ‘look’than the HDR?

• How do you verify that the HDR delivery coding(PQ, HLG, Dolby Vision) is correct for the targetdevices?

SMPTE ST-2084 PQ HDR versus BT.1886 SDR

51

200 400 600 800 10001 10

5

1 104

1 103

0.01

0.1

1

10

100

1 103

1 104

Light output (nits or cd/m^2) vs CV

YoPQi

Yo1886i

230 940

cvi

m12610

.4096 4=m1 0.159301757813 c2 .2413

409632 =c2 18.8515625

m2 .2523

4096128 =m2 78.84375 c3 .2392

409632 =c3 18.6875

c1 c3 c2 1 =c1 0.8359375 =Lpq 10000

Ypq( )v .Lpqmaxi v

1

m2 c1

c2 .c3 v

1

m2

1

m1PQ EOTF:

Ypq_inv( )vc1 .c2 vm1

1 .c3 vm1

m2PQ OETF:

10-bit Code values

Note that ST.2084 has more gainabove code value 230. Thismeans more quantization errorof bright light. However, the eyeis less sensitive to changes inbright regions.Conversely, it has less gainbelow 230 so there is lessquantization error in the blackswhere the eye is most sensitive.

BT1886 EOTF:

Lo 100

nits

nits

Y1886( )v .Lo ( )maxi( )v b

2.4 b 0

maxi( )x if( ),,<x 0 0 x

70 80 90 1001 10

5

1 104

1 103

0.01

0.1Light output (nits or cd/m^2) vs CV

YoPQi

Yo1886i

cvi

NOTE:PQ OETF is inverse of EOTF, sosystem gamma is unity

100X Brighter @ 100 IRE

100 IRE

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ST.2084 (PQ) Dynamic Range

52

HDR MAPPING INTO CAMERA F-STOPS (0 = 20 NITS, 2.5 = 100 NITS)(5000 nits)8

(.08 nits) -8

6

4

2

-2

-4

(20nits) 0

-6

Stops

Adapted Eye~7-stops

Brig

htad

aptio

n

Dark

adaption

(100nits)2.5

0 1 104

2 104

3 104

8

6

4

2

0

2

4

6

8Light-Stop Histograms (0=18%)

2.5

0

stop1886k

stopPQk

,H1886k

Hpqk

BT709 on BT1886 Pix

HDR on BT1886 Pix

HDR on HDR Pix(matches originalwith only 7-bits)

HD

R O

nly

Zone

• HDR coding on HDR display is bestmatch to viewing scene

• BT.709 gamma on BT.1886calibrated display stretches blacksand actually increases DR

• HDR coding on BT.1886 display willlook washed out

• With an HDR master, DRcompression can improve the SDRpicture on a well calibrated BT.1886display

• HDR coding does not change APLsince it only provides more light inthe highlights and more light-levelaccuracy in the blacks

Scene Referred 709 to PQ LUT Conversion

53

0 20 40 60 80 1000

10

20

30

40

50

60

70

80

90

100Camera-side conversion BT.709 to PQ

% or IRE

SDR_2_HDR_CS ,,BT709i

100 1000

SDR_2_HDR_CS ,,BT709i

100 2000

SDR_2_HDR_CS ,,BT709i

100 5000

9 41

BT709i

Camera-Side ConversionBT.709 to PQ

BT.709 % IRE

SDR BT.709,100,1000

SDR and HDR displays DO NOT match.Blacks are stretched in the BT1886 Display but not in the PQ display (matches scene)

SDR BT.709,100,2000

SDR BT.709,100,5000

2084 HDR 0% 2% 18 % 90% 100%

709100nits 0 9 41 95 100

HDR1000nits 0 37 58 75 76

HDR2000nits 0 31 51 68 68

HDR5000nits 0 24 42 58 59

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Side by Side 709 and PQ

709 HDR PQ

SMPTE 2084 PQ Look Up Tables

55

Linear Ramp Test SignalBT.709

LUTST-2084 1000 NitsRef White 100 nits

LUTST-2084 1000 NitsRef White 300 nits

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Normal or Diffuse Reflectance White Point• Same challenge as with different camera formats

◦ E.g., a diffuse white point of 100 nits is set at 61% for S-Log3, 58% forLog C, and at 63% for C-Log

• HDR PQ◦ No agreement on Diffuse White point level◦ Many are using 100-200 nits as the default; others use 10k nits

• Camera operator or colorist/editor must also know what referencemonitor will be used for grading the content◦ E.g., If a 1000 nit monitor is used for grading, a diffuse white point of

100 nits is set at 75 % for SMPTE ST 2084 (1K)◦ If a 2000 nit monitor is used, diffuse white is set at 68 %

HDR Aligned at 100% Diffuse = 100 Nits

57

Nits

Rel

ativ

e C

ode

Valu

e

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Code Values - Narrow or Full?

• Standard ITU-R BT.2100◦ Full Defined

▪ Luma Y 0d –1023d for 10-bit▪ Chroma Cb/Cr 0d –1023 for 10-bit▪ 0d – 4092d for 12-bit Luma▪ Chroma Cb/Cr 0d – 4092d for 12-bit▪ Note:- SDI codewords excluded and range clipped

Narrow Defined▪ Luma Y 64d –940d for 10-bit▪ Chroma Cb/Cr 64d – 960d for 10-bit▪ 256d – 3760d for 12-bit Luma▪ Chroma Cb/Cr 256d – 3840d for 12-bit

58

Potential Issues with Bright HDR displays

59

• Colour shift in the Mesopic-level adaption• As light moves below Photopic (dominated by cones) and gets closer to Scotopic

(dominated by rods) colour saturation will diminish• This may occur in dark scenes in low-light home theatres

• Light/Dark Adaption (‘bleaching’ process rather than pupil size)• Sustained bright images cause the photopigment in the retina to reduce and can result

in the perception of after-images• Dark adaption can take seconds or even minutes• Changes from bright to dark scenes may take longer in dark theatre as opposed to

same scene in higher ambient light

• Viewing Distance• Static adaption is only about 7 to 9 stops• To take full advantage of HDR (>9 stops) with local adaption, you need to be closer

than 2 screen widths (eye strain risk)

• Large Area Flicker• Strobing of high peak light levels may cause distress (PSE BT.1702)• Perceptual flicker frequency may be increased since it is a function of retinal adaption• Frame rate judder may be more visible

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Monitoring for HDR and WCG

20 MARCH 2017 60

Monitoring for Wide Colour• Tools:

◦ Waveform, vector, gamut displays

• Measurements:◦ RGB level balance checks◦ Vector targets are slightly different◦ Ensure within legal gamut limits if content will be

down-converted from Rec 2020 or P3 to 709 or 601colour

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Monitoring for HDR• Tools:

◦ Test patterns, charts, gadgets for camera alignment◦ Viewing LUTs?◦ Waveform monitor

• Measurements:◦ Depends on HDR flavour

▪ ST 2084/PQ, HLG, Dolby Vision▪ Mastering reference (540, 1000, 1200… 10,000 Nits?)

◦ Set points will change for normal white, specularhighlights, 18% gray, reflective black and super black

◦ Metadata?▪ ST 352 VPID; ST 2086 static; ST 2094 dynamic

Monitoring for HDR

• Waveform monitor scales for different HDR formats◦ EOTF curves (PQ, HLG, S-Log, C Log…)◦ Units of nits, % reflectance, f-stops, code values◦ Mastering reference levels for HDR delivery (1k, 1.2k, 4k, 5k, 10k nits)

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Monitoring for HDR

• Zebra pattern on picture monitor for specularhighlight areas above diffuse white

• Luminance histogram

• Average picture level40 nits

Waveform Monitoring for HDR and WCG…• Makes camera set-up easier

• Makes colour grading faster and moreaccurate

• Ensures that you master correctly for alldelivery formats

• Helps you…

Stay ahead of the curve!

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