The Basics of LUTs

At the core, a LUT is an ingenious technical tool used in video production and post-production. Essentially, a LUT is a mathematical formula that transforms the appearance of video footage. This transformation restructures the color and tone value of each pixel in the frame, thereby altering the entire image’s aesthetic.
In layman’s terms, a LUT serves as a ‘translator’ between different color spaces. For example, a specific lut might change a flat LOG image into something more vibrant and aesthetically pleasing. Hence, a LUT helps video professionals save time and ensure consistency across their footage.
“Think of LUTs as Instagram filters for video production, retrospectively altering the visual presentation.”

1D vs. 3d LUT

A LUT can either be 1D (one-dimensional) or 3D (three-dimensional).
Now, you might be wondering – what is the actual difference between a 1D and a 3D LUT? Well, each one serves a unique purpose in various stages of video production, and they function in quite different ways.

1D LUT

A 1D LUT, to put simply, works linearly. It alters a single channel where an input leads to a designated output systematically. This means that it operates primarily on the brightness levels of your image where it does not see or alter the relationship between the colors. This makes it particularly useful in early stages of color correction, such as calibrating a monitor or adjusting the contrast of an image.

3D LUT

In contrast, a 3D LUT applies changes to all color channels simultaneously, which allows it to influence the contrast and hue of an image. Essentially it looks at both color and brightness. Every pixel in the image is viewed in relation to the other color channels, and how it should be corrected given its relationship with those channels. This gives it the capacity to carry out more complex and cinematic color grading transformations.

The Role of LUTs in Color Grading

A LUT can be envisioned as a mathematically precise translator for your video’s color palette. It intensely refines raw footage by modifying the hues, toning, contrast, and saturation. This ultimate tool gives you the power to convert your visuals into a highly professional, polished final product that’s ready to captivate your audience.

In essence, a LUT is a method for transforming colors in post-production, allowing video footage to appear more aesthetically pleasing or specific to a certain style. These changes can range from simple modifications of hue and saturation to complex alterations that completely transform the visual mood of a scene.

Exploring the Role of LUTs in Cinematic Storytelling

It’s fascinating to explore the role of Look Up Tables, or LUTs, in visual storytelling. LUTs have the distinctive power to bring a scene to life, tweak emotions and create an overall cinematic environment that pulls viewers into the story.
Every filmmaker uses unique storytelling skills to engage their audience. A significant part of this process is color grading, in which LUTs play an indispensable role. Applied during post-production, LUTs help to evoke specific feelings or convey particular elements of a scene to the viewers, amplifying the storyline.

Setting the Mood with LUTs

Consider a scene set in a cold, snowy, remote town. Filmmakers may apply a LUT that emphasizes blue tones to convey the chill, isolation, and potential danger. On the contrary, a warm, sun-soaked beach scene would likely have a LUT that brings out the oranges, yellows, and reds, creating a sense of warmth, relaxation and happiness.

Flavoring Scenes with LUTs

Different LUTs can create a diverse range of flavors within a single scene. Perhaps the director of a thriller wants the lead character’s discovery of a crime scene to feel shocking and unsettling. A LUT that exaggerates colors and increases contrast can achieve this, suggesting a heightened sense of reality.

Evolving Storytelling with LUTs

Over time, consistent use of certain LUTs can play an influential role in storytelling by creating a unique visual style that is tied to a particular character, location, or time of day. This visual consistency helps to anchor and guide viewers as the narrative unfolds, providing subtle cues that enhance understanding and heighten emotional impact.
LUTs serve as a pivotal tool in cinematic storytelling, offering a significant contribution in shaping the visual narrative and enhancing viewer’s engagement. The creative application of LUTs, paired with thoughtful color grading, can truly take a film or video project to the next level by deepening its storyline and making it more memorable and impactful.

The Science of LUTs: How They Manipulate Color Space

When it comes to the science of LUTs, it’s all about manipulating color space. Color space can be a tricky concept to grasp, but think of it as the range of colors that a camera can capture or a screen can display.
Every camera and display has its own distinct color space — with some having larger color gamut than others. While working with videos, it is often necessary to manipulate or transfer color information from one color space to another, and that’s exactly where LUTs come in.

A Colorful Affair

Ever wondered why some videos look visually stunning while others appear faded or dull? That’s often due to how successfully the color space has been managed. Manipulating color space with LUTs can lead to superior color depth, better contrast, and overall improved image quality.

In the context of LUT operation, a LUT takes the color value in your footage’s color space (input value) and outputs a new color value (output value) creating a color transformation. This transformation often follows a nonlinear path to ensure more natural color over the entire gamut.

Profiling Color Space Management

Successful color space management involves knowing both the source and target color spaces. This is because LUTs need precise color space information in order to generate accurate color transformations.

Source color space: Refers to the original color space from which the footage was shot. This color space defines the range of colors that the camera sensor could capture.

Target color space: This is the color space in which you want your final footage to be displayed. It could be anything from a cinema display color space, like DCI-P3, to a home TV range like Rec.709.

Essentially, a LUT serves as a bridge between these two distinctive color spaces.

Riding the Waveform

Another key aspect of how LUTs manipulate color space relates to the video waveform. A LUT can change the shape of a video’s waveform that plots brightness and color over time. Subtle alterations in this waveform can amount to significant changes in color and feel of the video, emphasizing the vital role of a LUT in creative color grading.

The Dos and Don’ts of Applying LUTs in Your Video Projects

Applying Look-Up Tables (LUTs) in your video projects can dramatically affect the aesthetic appeal and professional quality of your output. However, correct application is crucial. Let’s explore some of the best practices, as well as pitfalls to avoid, when using LUTs.

✅ Do: Understand Your LUTs

Before applying any LUT, it’s critical to comprehend exactly what it does. LUTs are mathematical formulas that affect the color and tone values across your video; understanding their impact will enable you to predict the effect they’ll have on your footage.

❌ Don’t: Rely Solely on LUTs

LUTs should never be used as a crutch or an easy way to color grade. While they’re an excellent starting point for color correction, they’re not meant to replace the process of color grading entirely. Highly detailed adjustments will still need to be made individual to each project’s needs.

✅ Do: Test Multiple LUTs

Testing out different LUTs on your footage can reveal surprising results and unexpected stylistic options. Don’t limit yourself to a single LUT so quickly; give others a chance and choose what works best aesthetically for your project.

❌ Don’t: Max Out the Intensity

Over-saturating your video with LUTs can cause it to look artificial or overdone. As a rule of thumb, if you’re questioning whether the color grading is overwhelming the original footage, it probably is. Try scaling back or reducing the intensity of your LUTs.

✅ Do: Learn How to Create Your Own LUTs

To obtain the most out of LUTs, consider learning how to create your own. This personalizes your videos and can establish a unique color grading style that identifies your work. There are numerous tutorials available that walk you through creating your own LUTs, greatly enhancing your video production skills.

❌ Don’t: Apply LUTs on Ungraded Footage

It’s not beneficial to apply LUTs on raw, ungraded footage. Instead, be sure to color correct and balance your footage first before any LUT is applied. This will ensure a better, more consistent result overall.

In conclusion, the appropriate use of LUTs can transform your video project, taking it from average to professional-grade quality. A little discretion and understanding go a long way in ensuring LUTs enhance rather than overpower your final product.

How to Color Grade with LUTs in Premiere Pro

Our Friend Eric Put together a film on how to color grade LUTs in Premiere Pro