Change duration between slides in album

A photo album slideshow is a convenience display. It has no settings. I know of no way to vary the default duration of slides in a photo album slideshow, from within the features of the Photos app, other than to create side-by-side duplicates to double the duration of the display. Converting to a project slideshow would give you more options.

-- Rich

You could use iMovie to vary the durations of your photos, then export the iMovie project to a file on your desktop, then import the file into your Photos album.

-- Rich

You can control the duration of individual slides in a slideshow run from an album, if you start the slideshow with an Apple Script, then pause and resume the slideshow after each slide using an Apple Script. Use the "Wait" command after each slide to wait a bit longer.

When you use Apple Script to start a slideshow from an album, you can control the timing a bit by stepping through the slides manually. Create a loop, where you do the following for each slide:

• Pause the slideshow with pause slideshow
• Wait for a few seconds with delay showslide_duration
• Resume the slideshow with resume slideshow

• then use next slide

As an example: This script is shuffling selected slides to play a random slideshow and display the title of the photo as a notification: Script: A Random Slideshow in Photos with… - Apple Community