The new Galaxy S23 Ultra allows you to record videos in professional mode. It supports 4K and 8K video recording from the native camera app. To shoot any videos in high definition, you have to first open the Camera app on S23 Ultra. In the app, now tap on Video. On the above side, you can see FHD option, which is default option to record the footage. Tap on it, and it will show all the available options.
Now, as per your requirement, you can select 4K @30fps or 8K @24fps format. After changing to required video mode, you can shoot it and save it in the Gallery. Note that, higher quality video will require more space on your Galaxy S23 Ultra.