How do you choose the right video color space for your project? I want to take you through a few basic color spaces and their applications.

A color space defines the limits of color gamut, gamma and white point for a video standard. All video is intended to be delivered and watched on some kind of display. How your video content will be consumed determines the color space you need to work in and deliver.

While HDR is sexy and more 4K HDR ready TV’s are being sold around the world, HDR monitoring is out of reach for most of us. So for now, I’m going to introduce you to the common video color spaces you’ll use for the web, mobile screens and SDR television.

Common Video Color Spaces

For the most part you only need to be concerned with one color space, and that’s the standard HDTV Rec. 709, or BT. 709.

If you want to know more about what a color space is, you can check out my post, What Is A Video Color Space?

sRGB

sRGB is a color space originally created for CRT computer monitors, graphics and print. It is almost identical to the Rec. 709 video color space. It’s based on the same primaries and has basically the same gamut as Rec 709. sRGB has a non-linear gamma in order to approximate the response of CRT display technology.

sRGB is still the standard for computer imaging, most consumer to mid level cameras and home printers. For professional printing and pre-press purposes Adobe RGB is often used which has an extended gamut that can be reproduced with professional CMYK printing.

Rec. 709

476px-CIExy1931_Rec_709

Rec. 709 is the recognized standard video color space for HDTV with a gamut almost identical to sRGB.

For broadcast it is defined in 8-bit color depth (values between 0 and 255) where black is level 16, and white is level 235. These are often referred to as “video levels”.

In the case of 10-bit color depth which is common for post production, full range levels are between 0 and 1023, but the final output is mapped to broadcast standard 8-bit 16-235 when creating deliverables.

Rec. 709 is by far the most common working and delivery color space for most projects. The Rec. 709 gamut is supported by all common display technologies across many devices.

DCI P3

DCI-P3 is a wide gamut video color space introduced by SMPTE for digital cinema projection. It is designed to closely match the full gamut of color motion picture film.

It is generally not a consumer standard and is mostly used for content destined for digital theatrical projection. However, notably Apple have adopted P3 color across many device displays, and the ability to capture photo and video in the P3 color space since iOS10.

Most professional reference monitors are able to display the full DCI P3 gamut.

You will often see a white point specified along with the color space, such as P3 D55, P3 D61 or P3 D65. The D number indicates the target white color temperature given in degrees Kelvin. D55 is 5500K, D61 is 6100K, D65 is 6500K, and the DCI standard white point is 6300K.

Rec. 2020

Rec. 2020 defines the specifications for UHD HDR. As far as color gamut, it covers a large percentage of the full XYZ color space. The standard defines 10-bit or 12-bit color depth. A few display technologies are Rec. 2020 compliant but as yet, it is not a common video color space to be working in for average post workflows unless you are mastering for HDR delivery.

This is becoming more common for commercial high-end delivery, but not something the home colorist or enthusiast will be equipped to undertake for some time to come. The average consumer HDR television is not going to cut it as a reference display for post production.

476px-CIExy1931_Rec_2020

Choosing The Right Video Color Space

The source camera files we typically deal with from a digital cinema camera provide at least 10-bit color depth and cover a native color gamut that far exceeds the requirements for DCI-specification, and in most cases covers or exceeds Rec. 2020.

Ideally you should be working in a wide gamut color space that encompasses all the expected output standards and have your monitoring calibrated to match.

If cinema delivery is one of the requirements, you should work in DCI-P3 using a calibrated DCI-spec projector, or monitor that covers the DCI-P3 gamut.

If HD broadcast delivery is the widest gamut color space expected, or computer desktop / mobile / web at any resolution, you should work in Rec. 709.

Color Management

Whatever color space you are working in, implementing professional color management is important for the best results. This means setting up your color grading working environment properly and calibrating all your displays.

That said, many of us have to make do as best we can with a consumer monitor or laptop screen, and for web delivery this is usually fine when targeting Rec. 709.

I hope this has provided a basic understanding about color spaces, what they are, the common standards, and how you should be using them.

For a more in depth look at professional color management the following paper from www.cinematiccolor.com is well worth reading: Cinematic Color, From Your Monitor to the Big Screen

9 Comments

  1. Thanks Richard for this.

    I have a question: If I´m doing a broadcast project in rec709 for a client and they would like to show this film in festivals (projected), do I need to do another copy set to dci-p3 and compensate the grading? I´ve had issues with films on festivals with bleached and blacks lifted and everything looked just terrible, but the same copy looked just as nice as it should on other screenings.

    • Hi Peter, good question. It depends on the technical requirements for the festival and how they are projecting. Are they asking for a full DCP from you?

  2. Pingback:sRGB vs Rec. 709 | Gerdami's Blog

  3. We have graded our footage in Adobe Premier Pro CC using a REC-709 calibrated 10bit monitor. But the rendered output looks almost 20% de-saturated. Tried many parameter combinations while rendering. Still not good enough. Any advice?

    • This could be a video levels vs data levels issue. It’s been a while since I’ve looked at the Premiere render settings since I use Resolve for everything. Unfortunately I might not be much help. Are you on Mac or PC? What codec format are you rendering to? Does the rendered file look correct when played out to the monitor but incorrect when played on desktop screen? or does it look incorrect on both?

  4. kishore yadav

    Hi Richard Lackey, there are different type of color space like P3, P3 D55, P3 D61, P3 D65. If i want to grade film what is the color space of Display/Monitor?

    • P3 is the name of the color space for DCI digital cinema, and the D number is the white point measured in degrees Kelvin, as a color temperature. D55 means the white point is 5500K, D61 will be 6100K and D65 will be 6500K. All fit within the DCI P3 gamut. 6500K is used in rec 709 and most other color spaces, 6300K is DCI white used specifically in DCI P3 target color gamut.

  5. Hi Richard,

    I have a good monitor with a wider gamut than Rec. 709. But I want my output video in Rec. 709 since it’s widely used. Question: do I have to change the color profile of my monitor to Rec. 709?

    Thank you!
    Helin

    • Hi Helin, your monitor will show whatever signal is input, so it’s your input to the monitor that matters in this case. If you’re feeding it Rec. 709, that’s what it will display. Calibration of your monitor is another separate matter. What type of monitor? and what is your monitoring path? I’m assuming you are using a video output card for your monitoring?

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.