Since the advent of non-linear editing, digital tools for video post production have come a long way. What used to be only available within a million dollar grading suite can largely be done these days with a decent laptop and an external calibrated monitor. Nowadays more and more filmmakers are using off the shelf software to craft their cinematic visions into a reality that can truly match Hollywood standards.
Here we will take you through the basic steps of how to colour correct and creatively grade your video project for maximum impact, as well as walk you through how to choose the right colour for your video.
Assuming that you have shot your project on a digital camera in either RAW or a flavor of Log file – we can be assured that our camera footage or ‘negative’ has a degree of latitude contained within the file. This latitude is the amount of information contained in that file, the more information, the more that an image can be manipulated in post. If your camera records to a memory card, the files that are written to it can be regarded as your ‘camera negative’ – just as in the good old celluloid days, your negative contains all of the images/data that your camera recorded to it.
Nowadays, colour correction software found within modern NLE software is sufficiently outfitted to handle footage from consumer cameras, right up to the highest end cinema range from makers such as Arri, Sony and RED. Software such as Adobe Premiere Pro, Final Cut Pro and Davinci Resolve have all been proven to deliver effective workflows for TV and film productions at all budgetary levels. For our examples, we will be using Davinci Resolve to show the main points of progress to successfully colour correct and grade your video footage.
Colour correction refers to the ground work that is best done first to prepare material for further adjustment. Here we will be adjusting white and black levels, contrast, exposure and white balance to give you an image with consistent colours. The main purpose of colour correction is to ensure that subsequent colour adjustments or creative grades render correctly. Colour correction is essential to allow visual consistency for your footage and scenes. If matching more than one camera to your timeline, it is very important that the images from multiple cameras are made to match in this way.
Applying a LUT
A look up table (LUT) is a preset adjustment for your camera type that once applied, will nudge the colours in your footage to the values of a known standard. In our case we selected the common Rec. 709 LUT which is the current standard for HD broadcast television, this is regarded as the “Input LUT.” Applying a LUT is a good time to white balance your footage, either with the Auto White Balance ‘picker’ or manually inputting temperature adjustments.
Our example clips were shot using the Sony FS7 camera that was recorded in S-Log3. The left side of the image shows the Log image straight from the camera, the right side with the desired Slog3 – Rec709 LUT applied.
The difference between a Log LUT and a Rec. 709 LUT is neatly explained in this video: https://youtu.be/J0ZCVfmfIYI
Unify your clips
Consistency across your footage is key. Take a look at your clips on your timeline and select one that has the most average in exposure and levels when compared to the rest of your footage. This way, you can try to match everything to a place that is somewhat unified. This can include unifying the blacks and whites throughout your clips, as well using secondary colour correction to ensure continuity with prominent colours throughout the timeline.
This particular clip in the timeline is not looking unified. It is an interior shot, where the white balance does not look correct in comparison to the exterior shots either side.
Two clicks and it’s done. By using the auto white balance ‘picker’ on the plate reflection, and rolling the colour temperature a notch cooler using the manual override.
Here are the original S-log files from the camera, pre LUT conversion or colour correction.
Here are the same frames after correct S-Log LUT applied, with some minor colour correction to unify the frames and keep continuity in colour, contrast and saturation.
A light grade to bring out the sky saturation was added as well as some added contrast to the distant mountains.
Ok so we’ve covered the very basics in colour correcting and adding a light grade, how about something more stylised? Many modern cameras allow for a preview LUT to be applied directly to the camera monitor, allowing a director or director of photography to see the desired end result whilst shooting, but with the added benefit of knowing that the preview LUT has not been ‘baked’ into the recorded footage when shooting RAW.
Having a preconceived idea as to the ‘look’ of a final image is becoming more of a common requirement these days when it comes to creative grades, as it can often inform wardrobe colour choice, set design and lighting departments to make adjustments for.
So having the ability to foresee the planned grade can be a very important feature, as it allows shots to be composed and lit for a desired look, yet if the decision changes later…the process can be reversed, as the preview LUT is simply metadata that can be swapped out or deleted. The advantages of custom preview LUTs can be for projects where a creative grade is known to be desired. An extreme example might be a preview LUT for ‘Day for Night’ for example, where the image might be heavily tinted blue with crushed shadows.
Likewise if you know that your scene is intended to be dark and have a specific mood, having a way to ensure that enough exposure is getting to your camera ‘negative’ can be a godsend when it comes to post.
There are many online resources to find preset creative LUT’s for free (and paid for) .To obtain the best results, always look for specific LUTs that are intended for the camera type that you will use on your project. That way you can be assured that the colour corrections are correctly configured for you.
The ‘Right’ Colour
Picking the ‘right’ colour grade for your video project is totally subjective and can depend on many things. It is almost always dependent on the subject matter and how a story is being told. Mood and tone are often imparted by how a motion picture is represented in it’s colour palette, saturation and placement of colour. As simplistic as it sounds, colour can trigger emotions in ways that we still don’t fully understand.
A great way to explore the possibilities of colour grading for your project is to first learn colour correction. As stated earlier, it is the bedrock to build any creative grade upon. Pick a NLE or grading software of choice, and find the relevant YouTube tutorials out there (there are hundreds!) – Once the technical side of colour correction is mastered, you can then proceed onto the grade and find yourself the ‘right’ colour for your story.