Wondering precisely what a LUT is and why people are asking you to supply one? There are times for LUTs, and times to avoid LUTs, and we can walk you through it all.

If you find yourself wondering “what is a LUT,” or, more specifically, “how do I use a LUT in my color grading,” you aren’t alone. LUTs are one of the tools we use in filmmaking with the most confusion surrounding them, which is surprising because they are actually pretty simple things once you get to know them.

What is a LUT?

To start with, let’s supply a simple LUT definition: a LUT is just a “lookup table.”

That’s it. It’s a table of values.

In fact, if you have a LUT of some sort (you can download them many places on the internet), you can open that LUT in TextEdit or Notepad and read it.

That’s it. Just plain text readable numbers in a specific order.

Every LUT format spells out what those numbers mean. So each number in the table refers to a specific color value in your image, and the numbers in the table tell the system how to change it. Make it brighter, make it darker, make it bluer, redder, greener.

That is it, it’s really that simple.

What this means is that a LUT file is one that can be applied to your image to change how it looks. Maybe you are shooting on a camera that is a little desaturated, and you want it to look more saturated? A LUT can do that.

It can make the image more contrasty, bluer, flatting, darker, or brighter.

Learn more at NoFilmSchool.