If you have upgraded from Mojave (or even an earlier version of macOS) to Catalina, the old desktop background will remain. If you prefer to set the new photo of the island of Catalina, you can.
If you had the well-known sand dune as a background under macOS Mojave, you will see that it is still there after the upgrade to Catalina. This also applies to every other image that you had previously set. For example, if you had set a picture of your vacation, it will remain your background under the latest version of macOS. Apple undoubtedly did exactly for that reason. The point is, however, that a dynamic version of the Catalina background – just like the Mojave sand dune) is available. That changes in terms of lighting throughout the day. To set Catalina as the background, first click on the apple in the menu bar, followed by a click System Preferences. Then click Desktop and screen saver in the opened window. Via the navigation panel on the left you will find below Apple and Desktop all kinds of images. First, there are the flagships of macOS, or the dynamic desktops. Click on the Catalina aerial photo and your desktop background will change in real time, adapted to the time zone you are in.
Static
If you find that changing background less pleasant or somewhat irritating, you can also opt for a static image. That can be done in different ways. In this way you can choose from in the selection menu next to the preview of the chosen theme Dynamic, Light (still) or Dark (still). Furthermore, there is a range of backgrounds available below Desktop. Firstly, the well-known aerial photo in both a day and night version. But also a whole series of other pictures made above, around and on the island of Catalina. Apart from that, you will also find some totally non-Catalina-related images, so you can go anywhere. And now that you have arrived in this panel: also click on Screen saver. You will find a whole series of screensavers below. Although they don’t have much practical use on a TFT screen, they are nicest to look at.
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