how do I keep a vertical image instead of it being cut horizontally
All the still images in the slideshow that are vertical are cut off in a horizontal format How do I change this?
MacBook Pro, OS X El Capitan (10.11.6)
If your images are larger (vertically) than your screen and/or the available options of the app you are using, then you will need to decrease the size of the photo before putting it in a slideshow. Depending on whatever you are using, you may need an image editing app.