Those kinds of questions are easily answered using the F1 key to access PD's online Help pages. The answer you're looking for is at the bottom of this
page.
You can also access that feature by selecting the Fade transition in the Transition room then click on the "Apply to all" button that will appear above the timeline, like this:
This message was edited 1 time. Last update was at Mar 29. 2023 22:28