Introduction

Most of the productions that get mastered in Dolby Vision will get color graded as this step provides the most flexibility and potential for adapting the captured content to achieve the creative's intended look. 

Where content is going to be color graded, it is recommended to use source material that best retains the native color gamut and original dynamic range of the content at the time of its origination in order to create high quality Dolby Vision content. 

Where content will be directly edited and then aired with just some minor color corrections or even without a color grading process, capturing in a format that matches to the color gamut and dynamic range of the delivery requirements can enable a simpler workflow. 

As Dolby Vision can deliver higher dynamic range with a wider color gamut, and at a greater bit depth than SDR delivery systems, ensuring these wider ranges are captured at the onset, is important to creating the best Dolby Vision masters.

Color corrected masters - Original Camera Sources

For mastering first run movies in Dolby Vision, the original camera files or original film scans are ideal as modern digital camera systems as well as negative film stock can capture 13+ stops of dynamic range.

The exposure and lighting decisions made on set will determine the level of dynamic range and usable color gamut for a Dolby Vision HDR master.  While it is possible to stretch the dynamic range of the content in post-production the best results are really defined by the HDR image that is captured in the acquisition phase.

Digital camera sources:

For any digital acquisition we recommend using either RAW recording (no de-mosaicing / de-bayering performed in camera), or if not available or applicable using a compressed source format in its lowest available compression and highest quantization (bit depth) using a “log style” OETF (Opto Electrical Transfer Function). Intra-frame codecs should be preferred over Long-GOP codecs.

Assuming a correct exposure, the following original sources can be considered as minimum requirements for Dolby Vision mastering.

Capture Format

• RAW - ArriRaw, RedCode, Sony X-OCN etc.
• Compressed - XAVC-I, ProRes or other I-Frame only formats

Quantization (min.)

• 16bit linear
• 10 bit log

OETF - Capture transfer function

• LogC, S-Log,3 Log3G10, etc.

Color Space

• Camera native color space - S-Gamut3, REDWideGamutRGB, Panasonic V-Gamut, etc.

No looks, color corrections or other transforms should be baked into the original camera files. Some cameras’ default color space is set to Rec.709 or sRGB. This color space should not be used for recording. Record in the camera’s native color space, instead.
 

Mobile media sources:

Depending on the budget, story, or when a small, flexible camera is required, creators might want to incorporate content captured by a mobile phone, like the iPhone 12 as well. Using phones to capture real-life situations also often has the advantage that those being filmed are more likely to act naturally than if a larger camera and recording equipment are being used. However, if you are in any doubt about whether a phone should be used as part of your production, as with any other camera selection, this should be checked with those who are commissioning the content you are producing. 

The Dolby Vision iPhone recording specifications (Profile 8.4)

Codec/Format:

• HEVC Main10 video in Apple Quicktime container (.mov)

HDR format:

• Dolby Vision with HLG base layer (Profile 8.4)

Transfer Characteristic:

• HLG (ITU-R BT.2100-1)

Color primaries:

• BT.2020

Chroma sampling:

• 4:2:0

Bit depth:

• 10 bit

 

Film sources:

Scanning Format

• ADX OpenEXR
• dpx

Quantization (min.)

• 16bit linear
• 10 bit log

Whatever system or workflow you choose, we highly recommend thoroughly evaluating and testing if your desired camera system and capture format is suited for your expected visual results in HDR.

Color corrected archive sources:

When remastering projects without access to the original camera originated source, consider using the color corrected output of the Digital Intermediate (DI) process.

Note that these sources should ideally have been created without any range limiting display transforms baked into the content during the DI process. Such transforms could clip or compress the highlight and/or shadow detail in the image, thus compromising the resulting Dolby Vision content.

For remastering movies released as film prints the above mentioned formats for film sources are suited either color corrected or if available and applicable non color corrected.

Whenever accessible, high quality scans from either the original camera negative or an internegative (IN) should be used for any re-mastering purposes.

High quality scans of an interpositive or internegative (IP/IN) might not be ideal.

Material from sources other than these may not produce visually compelling results in Dolby Vision.

For example, content coming from HDCAMSR sources may prove to be extremely challenging when trying to create Dolby Vision content that is visibly better than the SDR version. It is very likely that such content is stored as Rec.709, Gamma 2.4 on such sources.

It will often be desired for Dolby Vision imagery to have deep shadows and bright highlights with saturated colors. The extended contrast and wider color gamut will result in captivating content that is noticeably superior to the SDR version. For Dolby Vision tests and remastering projects, content owners should provide a master color reference (DCDM/DCP, Blu-ray master or broadcast master) for use as a color guide.