How do I slow down the speed of a photo slideshow I've put together on my MacBook Pro?
MacBook Pro 13″, macOS 15.6
In the project mode click on the stopwatch at the right to get the following view. The instructions are in the screenshot:
Are you trying to use File>Play Slideshow? That is just a quickie thing that has not controls.
For a serious slideshow, you should use File>Create>Slideshow>Photos. That has lots of control, including timing. See this for details:
Create slideshows in Photos on Mac - Apple Support (EG)
Adjust photo slideshow speed on MacBook Pro
