The Distracting Slideshow
macOS includes a feature that allows you to set a folder of images as your desktop background, and the system will automatically cycle through them like a slideshow. Furthermore, newer versions of macOS include “Dynamic Desktop” wallpapers (like the default sand dunes or mountains) that automatically shift their lighting and color palette based on the time of day in your current location. While visually impressive, if you are a professional photographer, a digital artist, or a colorist, having a background that constantly changes brightness and color temperature will completely ruin your color perception and eye adaptation while you work.
Locking Down a Static Background
To maintain a consistent visual environment and stop macOS from automatically changing the desktop wallpaper or shifting its color tone, you must select a static image and disable the rotation features.
Click the Apple logo in the top-left corner of your screen and select System Settings. In the left-hand sidebar, scroll down and click on Wallpaper. If your current wallpaper has a small circular icon with a sun and moon on it, it is a Dynamic Desktop. To stop it from changing throughout the day, click on the thumbnail of the wallpaper you want, and look for a dropdown menu that says “Dynamic.” Change this dropdown to either Light (Static) or Dark (Static). If you are experiencing a slideshow of your own photos, scroll through the Wallpaper settings until you see the “Auto-Rotate” toggle switch or a dropdown menu that dictates the time interval (e.g., “Change picture: Every 30 minutes”). Turn this toggle Off, or select a single static image from a folder to break the slideshow loop entirely.