What is a LUT?
A LUT is a color-grading tool that can be applied to footage to give it a desired look. It looks at the initial color information from source footage and manipulates those values. Generally, a LUT transforms footage which probably isn’t ready to be shown to the public, and preps it for viewing. Think of it as a makeup artist for video footage.</p
Unlike a makeup artist, a LUT doesn’t think for itself. It’s just an information sequence that applies changes according to its settings. LUTs are devoid of any artistic instinct or real understanding of how the image should look. This is why manual color correction is important in getting footage to a desired look. But a LUT can be a big help in getting there.
What is so Great About LUTs?
LUTs Make Post Production Easier
A LUT can get your footage into the right color space so you can begin proper grading or give the footage a stylish look from the get-go. Able to be applied to individual shots or the entire timeline, LUTs can speed up the color grading process, so you aren’t stuck performing menial tasks. Simply put, a LUT is a color grading tool. Like any tool, it can be used in a variety many ways, and it’s hard to say what are proper and improper uses. It is up to the artist to use it how she feels appropriate.
LUTs Can be Used by Anyone, Anywhere, Using Any Editing Program
A universal color grading tool, a LUT can be used with just about any modern video editing or color grading software. The most noteworthy programs include Davinci Resolve, SpeedGrade, Premiere Pro, After Effect, Final Cut, and Photoshop. Before LUTs, video programs used their own color grading presets, and the presets from one didn’t open in another program. Now, a filmmaker can create a LUT and share it with other filmmakers, not matter the programs anyone uses.
What Ways Can You Use A LUT?
A LUT is a tool which assists in the process of creating an image’s final look (how the viewer will see it.) However, video professionals use LUTS a number of different ways to reach their final looks. LUTs can be used for both technical and creative purposes, and we can break them down into separate categories by how they are applied through the production and post production process.
LUTs are commonly thought to be applied in the post production process, but they are also useful tools during shooting. Some cameras and monitors can load LUTs for monitoring. This way, filmmakers on set can get an idea of how the colors will turn out in post.
Similar to the monitoring LUT, the calibration LUT works with a display to ensure it shows the correct color values. Different types of projectors and broadcast monitors can represent colors in different ways. If a LUT is created with the understanding of what is wrong in a particular display, it can fix how the image will turn out and ensure colors are represented as intended. Calibration LUTs are great because they make the image look consistent no matter the presentation format.
Also called a conversion LUT, a transform LUT takes an image from one space to another. Transformation LUTs establish a color space before starting the color correcting and grading process.
A viewing LUT affects an image’s visual. Some LUT users apply viewing LUTs to quickly and easily give others an idea of how the grade will look. Others use viewing LUTs as the Final look. As I see it, there are two types of viewing LUTs. They are Film Emulation LUTs and Look LUTs.
1D and 3D LUTs
LUTs can manipulate colors via two different manners. These processes lend to the names give for these LUT styles, which are 1D and 3D.
A 1d LUT looks at a specific color value and gives a corresponding output for that value. With a 1D LUT, you will have a set of values for red, a unique set of values for green, and a unique set of values for blue. 1D LUTs can account for every possible color value.
3d LUTs mix the color values. 3d LUTs, which look at the combination of values, can’t cover every possible color combination. Camera manufactures make their own LUTs for their cameras.
Digging Deeper Color Science
So far, my description of LUTs is a bit narrow. But I believe it’s the best way to frame what a LUT is for an indie filmmaker’s purposes. LUTs are very broad and can do a ton of work outside of the color grading process. Now, if you’re still interested, I’ll flesh LUTs out a bit more.
A More Technical Description of What a LUT Is
A LUT is a series of numbers which have been pre-calculated and mapped out into a matrix or a “table.” This matrix examines or “looks up” an image’s input values and then assigns modified output values. This modifying of values changes how the footage appears to a viewer. A LUT makes its modifications by changing values in color, contrast, and saturation. LUTs can modify one or all of these values to varying degrees across the entire color spectrum.
Intended Use and Criticism of LUTS
There is much debate online about the proper use of LUTs. Most criticism is centered around viewing LUTs, as they are sometimes views as a cheap substitutes for a real colorist. Many critics feel that armatures put to much faith in LUTs, thinking of them as magic bullets that make flawed footage look stunning. Others feel that LUTs are fundamentally flawed for color grading because LUTs can’t adapt to subtle lighting and color difference between separate shots. As a result, a LUT cannot bind a sequence of shots together cohesively. Though the criticisms vary, professionals in the film industry agree that there is no substitute for a colorist. However, tight time tables and lack of budget can make hiring a colorist impossible.
LUTs can open up the capabilities of your footage. The right LUT can stretch the data to its limits, giving you the most dynamic image possible. However, it’s important to remember that a LUT is just a tool. Like mentioned before, it’s an unthinking number sequence. Proper usage is what matters. You can apply it and be done or use it as a starting point to make your footage look truly unique.
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