Create a camera LUT inside DaVinci Resolve

[Tom Evans]

Can someone please walk me through the process of creating a camera LUT inside of DaVinci Resolve? Can the most common high-end cameras such as RED/ALEXA read Cube files? Anything I should think about when creating a LUT for this purpose?

[Orash Rahnema]

Red can read cube, as far as I remember, Alexa can't. 

For the Alexa, depending on the model you have to use, on the Alexa xt you can only use a 1d lut and matrix and if I can recall the format is. Xml. 

On Alexa mini, Amira, lf and basically all the arri camera after the Amira you can use a 3d lut and the format is. Aml

I never had problem with a 33*33 lut but since you have to convert your cube lut into an aml you better reduce it to 17*17

I use lattice to convert the cube into the aml. 

[Kai Klassen]

Hi, for Arri cameras there are official tools you can use to create the aml or xml for in-camera use.

For the ‚newer‘ cameras:

https://www.arri.com/en/learn-help/learn-help-camera-system/tools/arri-color-tool

 

For the ‚older‘ cameras:

https://www.arri.com/en/learn-help/learn-help-camera-system/tools/arri-look-creator

 

The ‚Arri color tool‘ is also handy in a different way. Not only you can use it to transform the cube to aml, you also can import luts and convert them to any other lut format (e.g. Nucoda).

No batch convert though, as it is not especially meant for this purpose.

But its for free and if you have a lut that you actually need in another format it works. 

 

Cheers

 

[Anton Meleshkevich]

Usually you create a LUT for a monitor, not for a camera. LUT should be a 'log-to-video + grade' size17 LUT.

Basically you don't want to bake  any cdl to a LUT, but your DP may want you to do that. So you probably should tell your DP to adjust temperature AND TINT in a creative way instead of just set and forget 5600 for daylight and 3200 for tungsten. Or you will have to bake cdl-like corrections (or more accurate color balance in linear gamma) to LUTs for each scene to make LUTs work properly (especially extreme teal-orange LUTs). Of course you can create cdl on-set. But I like to avoid this as much as possible. Just my personal preference.

 

Also test your LUT with all kinds of neon lighting.

[Keidrych wasley]

On 9/12/2019 at 2:05 PM, Anton Meleshkevich said:

Usually you create a LUT for a monitor, not for a camera. LUT should be a 'log-to-video + grade' size17 LUT.

Basically you don't want to bake  any cdl to a LUT, but your DP may want you to do that. So you probably should tell your DP to adjust temperature AND TINT in a creative way instead of just set and forget 5600 for daylight and 3200 for tungsten. Or you will have to bake cdl-like corrections (or more accurate color balance in linear gamma) to LUTs for each scene to make LUTs work properly (especially extreme teal-orange LUTs). Of course you can create cdl on-set. But I like to avoid this as much as possible. Just my personal preference.

 

Also test your LUT with all kinds of neon lighting.

Just to add a layer to the conversation. Many DoP’s use custom LUTS some will be designed for the camera eg a .aml for the newer Alexa’s. Other DoP’s will use a custom lut loaded into a monitor. Roger Deakins uses one LUT only and has done since he started working with the Alexa. He has made minor changes to saturation and contrast for some films. The LUT has contrast curve baked in so that the image on the monitor 95% represents the final look of the finished film. This lut is then taken into post production for a consistent look from set to grade. This is why eg Sicario was graded in a week. Roger mostly shoots at 3200 or 5600 and creates the look from the lighting rather than a white balance / tint change. I’m a fan of this ‘one light’ one LUT approach but it won’t work for everyone of course. In resolve you can create a lut simply by manipulating the image with nodes then right clicking the timeline still and exporting a 32 cube LUT which you can the convert to whatever in lattice or if for Alexa mini etc use their free color tool. In fusion you can create 64 cube luts etc and get even more precise. Personally i’ve worked in aces and created a lut from a modified cinegrain pipeline 2383 lut which I modified to my liking then converted for use with the Alexa mini in camera. I’ve been very pleased with the results.