Web Development: How to Colour Correct and Grade Flat Video Fast With Look-up Tables (LUTs) in Premiere Pro

Wednesday, December 2, 2020

How to Colour Correct and Grade Flat Video Fast With Look-up Tables (LUTs) in Premiere Pro

Getting the balance right between file sizes, speed and quality often means setting your camera to compress your image into flat film footage. In this tutorial, you'll learn how to use a corrective or creative LUT for Premiere Pro to tease out the best from that flat footage and have it looking great, in no time.

Flat Footage

The result of recording a lot of sensor information while balancing size and speed is a much flatter-looking, washed-out image which needs some colour grading and adjustment. In retaining more of the information in the highlights and shadows, the highlights are darker and the shadows are lighter, resulting in a very low contrast image, but one with far more scope when it comes to editing.

There are three main recording methods that produce flat, compressed footage, raw video, ProRes video, and Log video. Log profiles and ProRes Codecs are more widely available, and produce smaller file sizes than if you were trying to shoot raw. As trade-offs go, it’s not a bad one – you get manageable files but still have captured a good dynamic range to be able to get more out of your footage.

Raw Video

When it comes to shooting video or making photographs, we often think of raw data capture as the pinnacle of quality, as it’s recording as much of the sensor information as possible without any processing, and with limited compression. Even for photography this can yield some huge file sizes, but when it comes to video it’s just about unmanageable for most of us in terms of storage and computer costs just to work with the footage. Raw video essentially unenviable as-is, needing conversion to video with special codecs and high-spec equipement.

ProRes Video

ProRes is what I’ve come to think of as raw-lite. It’s a series of codecs developed by Apple that essentially store each frame as its own image in the video file (known as intra-frame) and each frame is encoded and decoded independently of the rest, which results in bigger files but also makes them easier to read in your editing software, meaning you have a slightly easier time of editing larger files. ProRes has become an industry standard and a variety of options are available on a range of cameras. For example, the Blackmagic Pocket Cinema Cameras come with ProRes 422, 422 LT and 422 Proxy, all of which are variations of the ProRes codecs, balancing size, quality and speed/complexity depending on your needs. If you’re feeling extra thirsty for lovely, nerdy Apple codec data, they’ve written an interesting white paper.

Log Profiles

Since technology has improved in leaps and bounds and become more affordable, there are more casual, amateur, and semi-pro film makers who need to make high-quality productions, but in a manageable and realistic way. Most camera manufacturers offer versions of something called Log (logarithmic) footage which are profiles customised to their specific camera abilities and compatible with widely-supported compressed video formats. Log profiles have a much wider dynamic and tonal range when compared to regular linear profiles, which means you capture more detail in shadows and highlights that might otherwise be lost.

How to Correct and Grade Quickly With Look-up Tables

LUTs, or look-up tables, are image adjustment profiles can be a quick and easy way to bring your video back up to a good base-editing point (i.e. restore the colour and contrast) and also to colour grade and stylise your footage. Here, I’ll take a look at how you can quickly and easily install and apply a LUT in Premiere Pro. Here’s what I’ll be using:

Ultra Color | LUTs pack for Any Software

How to Correct and Colour Grade Flat Video Footage With LUTs (Look up Tables)

Open Your Footage

Open the footage that you’d like to apply your LUT to and highlight it by clicking on it. It needs to be highlighted for the LUT to apply – if you have more than one piece of footage open, highlight the one you’d like to work on.

Load in Your LUT

Go to the Lumetri Color panel. There are two ways to load in a LUT.

Loading in your LUT in Basic Correction

1. In Basic Correction you’ll see Input LUT. Click to drop that down and you’ll see some default camera profiles in the list already. Click on Browse and it’ll open up your File Explorer for you to navigate to your LUT and open it.

2. In Creative there’s a dropdown menu next to Look. Hit Browse and you can navigate to where you’ve saved your LUT and click Open.

Important: Which option you’ll use will depend what your aim is. Essentially, the Basic Correction tab should be used for LUTs that are corrective. By that, I mean they bring your flat footage to a good editable base point. Creative is how it sounds, for LUTs that are intended to colour grade your footage.

You can actually install any type of LUT in either section, but choosing another in the Creative menu would simply replace any previous one you had selected. If you wanted to use both a corrective and a creative LUT, you’d need to install them in the appropriate sections.

Also, with Creative, you’ll get an opacity slider to control the effect - as above- so you can decrease it from 100 down to 0, or up from 100 to 200.

I’ve gone for Cinematic 04 to demonstrate.

Make Basic Corrections

If you want to flip between your before and after so that you can see the effect, head over to Effects Control and turn Lumetri Color off and on.