Saturation is one of those fundamental pieces of a look that for me sits right next to saturation in terms of importance. That being said, saturation also is one of those pieces that can easily be overlooked. It’s easy to just adjust your global saturation dial and move on to other, ‘shinier objects’ in the look development process when you should spend time dialing it in before moving on to anything else.
Simply put saturation describes the intensity of a color in relation to the absence of color. Adjusting it can make colors appear vibrant or muted, and affect your narrative or visuals in a variety of ways.
What Is Image Saturation In Color Grading?
At it’s core, image saturation simply describes the intensity of a color. If you’re talking about how saturated the reds in an image are, you are describing how “red” it is in relation to the absence of color.
Take the below color wheel, where at the center is the absence of color – also known as white. Saturation is essentially the distance of a color from the center of this wheel. The greater the distance from the white, the more saturated a color is.
In terms of look development in color grading, color saturation is one of the fundamental elements you should be considering. Similar to how contrast is the foundation of light and shadow, saturation is the foundation of color. The way saturation is shaped will play a major role in how the colors in your image make the viewer feel.
It serves your look on both a global and local level. Saturation can be applied to your image as a whole with a saturation dial adjustment, or it can affect particular colors.
It’s a versatile tool that you can in a handful of ways to adjust a variety of aspects in your look. With a number of tools and methods to tweak the color saturation in your image, it’s a tool you should be familiar with as a colorist, and a key tool in color grading toolbox.
Importance Of Saturation In Color Grading
You can think of contrast and saturation as the “meat and potatoes” of color grading. Think of contrast as the meat – like a hearty centerpiece. On its own, it provides depth and structure, and in the instance of a monochromatic or black & white image, can be enough to stand on its own.
Next consider saturation, our “potatoes”. When paired with the meat it adds another layer of flavor and complexity to help round things out. In the case of our image, it’s the saturation that adds additional layers of depth, and helps to create a richer visual palette.
Outside of a rich, well-crafted visual palette, it also has the ability to enhance or magnify particular storytelling elements. The difference in saturation between scenes can evoke different emotions and enhance the story, depending on the context.
When we overlook saturation entirely in an image, we’re sidestepping elements that can inject more interest, depth, and storytelling into our images.
Impact on Colors
When looking at the mechanics of color grading, image saturation tends to the the go-to lever to pull when adjusting colors. It’s the logical first tool and offers everything from sweeping global adjustments, to nuanced hue-specific tweaks.
At the global level, adjusting tools like the saturation dial, vibrance dial, or drawing a custom saturation curve, you have the power to shape the overall look of the colors in your image.
On the other hand saturation can be adjusted at the local level. By manipulating specific hues you can carve out different pockets of contrast and fine-tune your color palette.
Stills from Causeway (2022), left, and Bullet Train (2022) right, showcasing two wide differences in color saturation.
Let’s say we want to increase the saturation of reds in our image. You could use this to highlight a character’s wardrobe, enhance a setting sun, or draw attention to a significant prop. It’s ability to emphasize particular elements or create additional contrast in your scene is what makes saturation shine on the local level.
Ultimately whether used locally or globally, saturation should act as a cornerstone of your color grading process.
Impact on Moods and Themes
Image saturation is a dynamic tool that can be used to vastly dictate the feel, mood, or theme of your look. The same scene with a variety of different image saturation levels can tell strikingly different stories.
Increasing the color intensity to create a higher saturation level might help instill a level of brightness, cheerfulness, or optimism in a scene. A desaturated frame on the other hand, where colors are far more muted, can take on a more somber or dark tone. It all depends on finding the right balance and usage of saturation for your image.
Saturation in color grading can be a nuanced tool, allowing for selective adjustments. For instance, by saturating a particular hue, we can amplify a critical storytelling element or guide the viewers eye to a particular part of the frame. It’s similar manipulating your lighting to emphasize a particular part of the frame, helping ensure the audience’s attention is exactly where it needs to be.
Operations: Working with Saturation
As with anything in color grading, there’s a variety of ways to adjust saturation in color grading. Many of which I haven’t even touched on here. But when adjusting your image it’s important not just recognize what you’re doing to your image, but understanding the ‘how’ behind it. Below I’ve mapped out a few of the most common adjustments and some of my favorites – in no particular order.
Saturation Dial or Slider
The saturation slider or dial is the basic, straightforward tool most start with. It simply adjusts the overall saturation like a volume knob, raising all levels at once.
A simple, global saturation can have it’s role in color correction or other instances. However it often ends up acting as the default when the are other more precise tools to consider.
Color Boost or Vibrance Dial
The Color Boost dial focuses on boosting saturation in less saturated areas without affecting already vibrant regions. While it has more nuance than the saturation dial, drawing a custom saturation curve will let you accomplish this same adjustment, just with more control.
HSV or HSL Color Space Saturation Adjustment
The HSL or HSV adjustment is my preferred method, though it’s a bit more complex. As with several other topics I’ve discussed, Cullen Kelly has a great video on this technique, but I’ve also done my best to break it down below.
Through node system built into Davinci Resolve, you can transform your image into an HSL (or HSV) color space. By moving into this color space, your Red, Green and Blue channels become Hue, Saturation, and Lightness. Giving you a specific channel for saturation.
By disabling Disabling H and L, you can adjust only saturation in this node through the primaries or curves. This pure color saturation adjustment provides an additional level of control over the specific areas of saturation in your image.
Saturation vs Saturation Curve
This tool let’s you adjust saturation based on its current intensity. Meaning you can increase saturation in the less saturated regions, or decrease it in the more saturated regions, or anywhere in between.
It’s operationally similar to the saturation curve found in the HSL / HSV method, but in my opinion is a bit harder to control in some cases. Ultimately it depends what I’m using it for.
Image Saturation: The Potatoes Of Color Grading
As I mentioned, saturation is one of those fundamental steps in color grading. It’s one of the big building block parameters you’ll likely want to figure out before jumping into more nuanced adjustments. It’s a key piece that can add visual and narrative impact to your image, so it’s worth spending time on and developing as a major step in your look.
For me it all comes back to starting broad and working your way towards the more detailed elements of color grading – and saturation is no exception to this rule.
Keep grading -r