30 Years of Rec-709.
Most of us are familiar with Rec-709. It is the colourspace for standard dynamic range television that was introduced in the early 1990’s. Most of us have been working with and delivering Rec-709 content for the past 30 years.
Because Rec-709 has been around for so long, the majority of the editing and grading software that we use defaults to Rec-709. Rec-709 has a limited dynamic range and a limited colourspace. It was designed around the TV technologies available in the 1990’s when Cathode Ray TV’s were still dominant and LCD screens were nowhere near as good as they are today.
But things are changing.
Most good quality phones, tablets, laptops and TV’s on sale today support bigger colourspaces than Rec-709. And most can now display high dynamic range HDR images. Streaming services such as Netflix, Amazon, Hulu etc are all streaming HDR content. Even YouTube and Vimeo fully support HDR. Eventually HDR will become completely normal and Rec-709 will fade into obscurity.
But right now we are in a transition period where a lot of content is still mastered and delivered in SDR but at the same time there is a need to deliver more and more HDR content.
Colour Management.
One way to make this easy is to use colour management in your editing and grading software. In a colour managed workflow the editing/grading software will try to determine the colourspace of your source material by reading the metadata contained in the file. Then it will determine the required delivery colorspace, usually based on the setup of your monitor or you can tell the software which colourspace you want to deliver your files in.
The software then converts from the source colourspace to the final output colourspace. The end result is that regardless of the colopurspace of your source footage, it will look correct on your monitor with the correct contrast and correct colour saturation. All your grading adjustments are applied to your footage in it’s original state which maximises the final image quality. This also makes it possible to change the output colourspace from one colourspace to another without having to change the grade – one grade can be used for many different output colourspaces. All you need to do is to change the output colourspace setting.
OK, it isn’t always quite as simple as that – you might need to make some fine tuning adjustments to your grade if you switch your output between HDR and SDR. But overall, if you grade something correctly for HDR and then switch to an SDR output, it should still look pretty good and this greatly simplifies your workflow if you need to deliver in both HDR and SDR.
S-Log3 is not, and never has been flat!
Colour Management.
One way to make this easy is to use colour management in your editing and grading software. In a colour managed workflow the editing/grading software will try to determine the colourspace of your source material by reading the metadata contained in the file. Then it will determine the required delivery colorspace, usually based on the setup of your monitor or you can tell the software which colourspace you want to deliver your files in.
The software then converts from the source colourspace to the final output colourspace. The end result is that regardless of the colopurspace of your source footage, it will look correct on your monitor with the correct contrast and correct colour saturation. All your grading adjustments are applied to your footage in it’s original state which maximises the final image quality. This also makes it possible to change the output colourspace from one colourspace to another without having to change the grade – one grade can be used for many different output colourspaces. All you need to do is to change the output colourspace setting.
OK, it isn’t always quite as simple as that – you might need to make some fine tuning adjustments to your grade if you switch your output between HDR and SDR. But overall, if you grade something correctly for HDR and then switch to an SDR output, it should still look pretty good and this greatly simplifies your workflow if you need to deliver in both HDR and SDR.
S-Log3 is not, and never has been flat!
S-Log3 and other log formats should never look flat. The only time they look flat is when there is a miss-match in the colour space between the material and the way it is being viewed.
S-Log3 in a Rec709 project looks flat because of this miss-match, this is NOT how it is supposed to look. But because in the early days most software only supported Rec-709, S-Log3 always looked wrong and as a result looked flat. In legacy workflows where there is no colour management the most commonly used solution to make S-Log3 look right is to add a LUT. The LUT transforms the S-Log3 to Rec-709 (and perhaps adding a creative look at the same time) so that the contrast and colour now looks correct.
Need To Deliver In HDR.
Need To Deliver In HDR.
But we are now starting to need to deliver content in a lot more standards than just Rec-709. HDR10, HLG, Rec2020 etc are now common and LUT’s designed to go from S-Log3 to Rec709 are no use for these alternate colourspace outputs.
So, most of the editing and grading software platforms we use are moving to colour managed workflows where the software detects the colourspace that the source material is in as well as the colourspace you are monitoring in and then automatically transforms the source material to the correct output colourspace. This eliminates the need to use LUTs, your footage will always look correct. This way all your grading adjustments are applied directly to the source material without being restricted to any particular colourspace and you can change the output colourspace to different spaces depending on what you need to deliver and you don’t need to change the grade for each alternative output.
By default in the latest version of Premiere Pro colour management is normally disabled, but some earlier versions enabled the colour management by default.
Enabling Colour Management.
Enabling Colour Management.
To enable colour management in Premiere Pro 2025 (version 25.0 and later) go to the Lumetri panel and under “Settings” “Project” enable (tick) the “log auto detect colour space” setting. Now Premiere Pro will detect the colourspace that your footage was shot in and colourspace transform it to you projects output colourspace. It is also worth noting that there is an additional setting that allows you to select the correct viewing gamma for the desired output, whether you are making content for the web or for broadcast TV.
If you want to deliver in HDR a bit further down in the settings you will also find the ability to change the timelines working colourspace, under these setting you can quickly change the timeline from Rec-709 to Rec2100 PQ (HDR10) or Rec2100 HLG for HDR. Changing this setting will change the working and output colourpace – note that if the colourspace of your monitor does not match these settings the image will not be correct – for example if you are using a Rec-709 monitor and you select Rec-2100 PQ the viewer images will appear flat.
If using a computer with a colour managed HDR screen, for example a MacBook, you will also need to allow Premiere to manage the computers Display Colour Management so that the viewers are displayed in the correct colourspace and then enable Extended Dynamic Range monitoring if the monitor is capable of displaying in HDR in the Lumetri settings under “Preferences”.
Be aware that if you allow Premiere to manage your colourspace this way you will no longer be able to use the majority of the LUT’s designed for S-Log3 as these LUT’s include a colourspace transformation that you no longer need or want. But – now you are free to deliver in both SDR and HDR without having to create different grades for each.
The colour management in Premiere is still somewhat basic, but it does work. But it’s very difficult to use the colour management and LUTs at the same time. Personally I much prefer the colour management in DaVinci Resolve which has a lot more options and the ability to add additional colourspace transformations as part of the individual grade used for each clip. This allows you to add LUT’s designed for a huge range of different colourspaces within different overall colour spaces.
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Thank you for this article Alister. I’ve been grading HDR since 2019 (REC2100 or REC2020/ST.2084@1000 nits.) To me, HDR was a bigger leap than HD to 4K. The results are stunning, and the SDR downmix looks great! The BIG advantage to grading HDR is what you can do in the shadow areas. True, you get brighter highlights and specular, and without having to do much highlight compression like SDR. I hope there is a movement to HDR and Wide Color Gamut. I use Davinci Resolve Studio, but it sounds like Premiere is catching up.