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 particular video standard. All video is intended to be delivered and watched on some kind of display device. This could be a television, PC or laptop display, tablet, phone, cinema projector, or HDR television. 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, reference grade HDR monitoring is out of reach for most of us. So for now, I’m going to introduce you to the common video color space 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.

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 photo 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. sRGB doesn’t have much to do with video, except to know that Rec. 709 video will look fine on a sRGB computer display.

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 usually mapped to broadcast standard 8-bit 16-235 when creating common 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 fully Rec. 2020 compliant but as yet, it is not a common video color space to be working in for average user post workflows unless you are mastering for HDR delivery.

This is becoming more common for commercial high-end delivery, but not something the home freelance DP/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. Some premium OLED HDR televisions can be calibrated for excellent Rec. 709 SDR reference monitoring, but not HDR.

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 at each step in your post monitoring pipeline 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’ve compiled a guide to building your own color managed and calibrated monitoring pipeline based around the excellent LG OLED TV’s. They can be perfectly calibrated for Rec.709 color correction and grading work.

You can add precision calibrated monitoring to your Resolve system for only $2200 – $3000 depending on whether you need to monitor in HD or UHD 4K.

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


19 Comments

  1. krishna avril

    Hi Richard, I usually work on Srgb, what is the professional way of colorspace while working… I usually do photographic image works and what colorspace the usual mobile phones or pc monitors have… will it change after finishing editing photo on my Srgb or rec709 colorspace image… I’m not able to find the reasonable answer anywhere… thanks.

  2. Thank you so much for the effort, I will read it all

  3. Hello Richard, hope you can help me. I am trying to figure out the best way to use colourspace, so that what I see in my preview window in resolve is also the same color and gamut as on YouTube and Vimeo, when viewed on a computer, laptop, tablet or phone. Im working with bmpcc4k footage in resolve and on a iMac 2017 (P3-DCI display).

    The closest I have gotten to my goal is with these settings in resolve:

    Input colorspace: Blackmagic design pocket cinema camera 4k film gen4
    output colorspace: SRGB
    limit output gamut to: output color space
    timeline to output luminance mapping: 1000 nits
    timeline to output tone mapping: saturation mapping.

    It is not spot on yet, it has some luminance shifts and a bit of color shifts when uploaded. It is very close to when I play the file in QuickTime on my iMac, but still not perfect.

    Hope you can help me and save me a lot of frustration.

  4. Dear Richard, my question is similar to Peter’s. I use at home a calibrated eizo monitor (threw sdi), and I’m usually mastering in REC709. If I have to deliver a DCP (with Davinci Resolve 15 kakadu), I include in the name that it meant to be screened in REC709 color space. But if I understand your article well, I should actually do it in DCIP3 (my monitor in theory is capable to cover it). In this case I should master the shorts/documentaries that I work on in 2 different ways (REC709 for web/Television and DCIP3 for theatrical screening), or is there a more automated method to switch between the 2 color spaces? What is the usual protocol in these cases? Thanks ahead!

    • Good question. Grading in DCI P3 usually involves a high end cinema projector, or a monitor you know 100% meets the standards. To be honest I wouldn’t make it any more complicated than it needs to be. I would recommend you grade in rec709 for both deliverables and let the Kakadu encoder handle the color space conversion to XYZ for the DCP. It will do that without any input from you. Hope that helps.

  5. 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.

  6. 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?

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

  8. 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.

Leave a Reply

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