What is LUT and why filmmakers should know about it?

what-is-LUT

Filmmaking is tricky; if you’ve spent any time involved in post-production, you’re probably familiar with how comprehensive the process is. Every frame is put under a microscope, and everything from the color palette to the tones and filters placed on top is meant to be cohesive and align with the film itself. 

Color grading is a tedious process; colorists have to go through each shot and render it just right to align with every other shot in the pipeline. This can take days, if not weeks! 

Speaking of colors, you might have heard of LUTs. Every industry has some acronyms that get thrown around by experts that leave beginners scratching their heads. We get it, that’s why we’re here with a complete guide on this particular acronym; LUT. What is it? And Why do you need to know about it? 

Let’s start by addressing the first question. 

 

Cut design & video review time in half

GoVisually is the #1 online proofing software to get visual feedback on Designs, PDFs & Video content.
Try GoVisually free today!

 

What is a LUT? 

A LUT or “look-up-table” is a collection of numerical values that alter the contrast and color of your video or image. These values are obtained by testing them out on a sample image, seeing how they look and copying the color gradient/contrast coordinates into a table. Moreover, the LUT itself samples values by using math to estimate values between regular intervals. This table is then used as a reference table to bulk modify images and frames in a film. 

Creatives such as colorists and filmmakers use LUTs to add uniformity to their work. If done right, shots modified by the look-up tables look just as good, if not better, than shots manipulated individually by a professional colorist. This takes much of the work off your shoulders, making workflows more efficient and quicker. 

Think of look-up tables as presets that you can apply to images automatically. These presets represent different colors, tones, and contrasts that you can play around with. 

 

All LUTs…

LUTs come in many different forms and have various applications. However, they are all similar in some aspects. Let’s discuss the three primary attributes of LUTs that will help you understand them better!

1. Work through sampling

LUTs don’t generate outputs for every value, which would result in a bunch of similar outputs with very minute differences. Instead, LUTs modify input values from samples at intervals, creating gradients that can alter images. For input values in between, LUTs use mathematical formulas to estimate input values and generate outputs. 

2. Are automatic 

LUTs don’t require human intervention, you don’t have to add input and output values for each shot manually. You can bulk edit shots by placing LUT values in a pipeline. This makes LUTs the most efficient way to bulk alter images while looking consistent and cohesive. 

Think about it instead of going through each frame individually to edit it and make sure it matches the previous one. You can enter a LUT in the rendering pipeline. It will automatically render the shots according to the input values. 

The input values need to be correct, though. The LUT will put out exactly what you put into it. It’s based purely on mathematics, so you’ll have to do the heavy aesthetic lifting for yourself! 

3. Require some extra attention 

Although LUTs don’t require human intervention during the processing, they require human intervention in the initial stage. You have to sample and add input values to the LUT so it can work its mathematical magic. You also cannot input requests for the kind of aesthetic you’re looking for. 

 

How LUTs help filmmakers

Now that we’ve covered a run-down of some essential attributes of LUTs let’s get into why filmmakers should get familiar with LUTs.

 

4-ways-LUTs-help-filmmakers

 

1. It gives filmmakers the aesthetic freedom they crave!

Creative LUTs help filmmakers explore different aesthetics with their projects. Unlike technical or hybrid LUTs, creative LUTs don’t necessarily have to be overly technically correct. You can use them to create and play around with the aesthetics of the shots without too much emphasis on technicalities. 

Still, you have to be careful with the gamma/gamut inputs into the LUT; the values have to be correct to get your intended results. Remember that LUTs are not independent thinkers. They rely on mathematics and formulas that are fed into it. 

2. They are more cost-effective

Since LUTs help bulk manipulates thousands of shots in the same time it would take to manipulate one, using LUTs is cost-effective. This is especially useful for independent filmmakers with tighter budgets. Instead of hiring editors to manipulate each shot individually, you can input a LUT into the rendering pipeline and let it work its magic!

3. Helps establish uniformity

Speaking of bulking editing, LUTs act as excellent presets to create uniformity across your shots and create a specific aesthetic for your work. Your LUT can act as your guide to how to make your work look as cohesive and uniform as possible. 

Instead of carefully editing each shot to match the other, LUTs being input into a pipeline render each shot automatically match one another. Of course, this also means creating a LUT that can be applied across multiple shots, which can be tricky but can be mastered with practice! 

4. Provides versatility

LUTs come in two primary forms; 1D and 3D. 1D LUTs see color grades across a one-dimensional grayscale. While this may sound flat, they work excellent for ‘flat’ photography to play around with the contrast. Some 1D LUTs also has three color rendering capabilities. Still, they require some extra attention to get it right because the colors don’t coordinate to create cohesive hues and color grading. 

3D LUTs offer more versatility; they read images across three primary colors; blue, green, and red. You can use them for more complex shots or make more complex edits. 3D LUTs help filmmakers make shots look just as they would if each shot was individually manipulated by a colorist. These LUTs employ mathematical formulas to sample values automatically, giving more depth to the color and contrast manipulation. 

 

Final takeaway

LUTs can be a tricky concept to grasp. For beginners, it takes lots of practice to understand them fully. However, once you’ve got the hang of it, the sky’s the limit! LUTs help filmmakers become more efficient with their editing and color grading, allowing them to create more aesthetically pleasing and visually uniform shots. 

Working in the creative field, collaborating with other teams is a given. However, collaborations often come with miscommunication and other hiccups that slow down work processes. For smoother filmmaking workflows, try GoVisually – the fastest and easiest video approval software! 

 

Want to send big files?

Need a quick way to share large files and creative assets?

With GoVisually Share, it’s absolutely free! Try today.

LinkedIn
X
Facebook
Email
Picture of Alina Zahid Khan

Alina Zahid Khan

Alina Zahid Khan is a storyteller, brand strategist, and growth manager at GoVisually. She loves creating value-driven content for creative professionals.
Subscribe to Newsletter
BEFORE YOU GO

Review & Approve Designs, Videos & PDFs 3x faster

Speed up your creative reviews & approvals with Govisually.

Get started with a Free Trial.