What is frequency separation?
Frequency separation is a technique used to separate color information from the other details of your image so you can adjust details and colors independently of one another. Usually, this is a high-frequency layer and a low-frequency layer. High-frequency information usually refers to fine details within an image, like hair, texture, pores, lines, and skin features. Low frequency, on the other hand, contains information about shadows, tone, and color.
With frequency separation, you can retouch either the high or the low frequency without affecting other areas — but it doesn't apply any actual edits to your work. Instead, it allows you to break an image apart so you can work on different sections, like modifying skin texture independent of color or shadow.
Here are some examples of tools and techniques you might use in tandem with frequency separation for retouching work.
Whether you’re working with people or products, you always want your photos to put their best foot forward. Techniques like frequency separation create a canvas for you to work within precisely so you’re able to make fine adjustments with other tools.
Once you’ve used frequency separation to parcel out areas of your image, you can then use layers, blur effects, shadow and color features, and blending to help you change the shape and tone of any image.
Once you’ve separated your frequencies, you can use the Dodge and Burn tools to control lighting and shadows — giving you fine control over your canvas and making edits and retouching efforts more rapid.
Frequency separation can take a lot of steps, but it’s an opportunity to learn Photoshop actions — a feature that allows you to record a particular set of operations so you can do complex edits and techniques in a single click. They’re handy when you need to make a series of edits that are the same every time.
When would you use frequency separation?
Here are some common examples of when you might need to separate the details of an image from its color information.