Endless Slideshow Screensaver allows to show up to 20 pictures in every [ Slideshow zone ]. The major difference between showing several pictures in every slideshow zone and having several slideshow zones is the ability to display a random number of pictures in every slide while the number of the slideshow zones is constant throughout the entire slideshow. Plus, although a transition is executed for the entire slideshow zone, you can still set how many photos are replaced in the current slide and select how those photos are replaced.
The number of photos in every slideshow zone can be modified in the screensaver settings, [ Slideshow ] tab, [ Media files per zone ] section:
If you want the same number of pictures in every slide - select this number in both [ From ] and [ to ] drop-down lists inside the [ Media files per slideshow zone ] section. But if you want to see a different number of pictures in different slides - select the minimum number in the [ From ] field and the maximum number in the [ to ] field.
By default, Endless Slideshow Screensaver replaces all media files in the current slide to create the next slide for the slideshow (if there are enough files). But you can change this behavior using the [ Next slide creation mode ] section. So, if you do not want to keep pictures from the current slide in the next one - select the [ The next slide replaces the selected number of files ] option. Then you can choose how many files to replace in the current slide to create a new one using the [ From ] and [ to ] drop-down lists. Just like with the number of media files in the zone, you can select the same number in both [ From ] and [ to ] to have the same number of photos replaced in every slide. But if you choose different numbers in those [ From ] and [ to ] lists, then a random number of pictures will be replaced (minimum [ From ] pictures and maximum [ to ] pictures).
After that, you can select what media files are replaced and in what order using the [ How to replace ] drop-down list. It offers the following options:
Multiple pictures are always positioned in a grid inside a slideshow zone and you can set the number of cells and rows of that grid for every possible number of photos (from 2 to 20).
Use the corresponding drop-down lists inside the [ Arrange media files in a grid ] section. Using different grids for different numbers of media files adds a lot of flexibility and is particularly useful for ultra-wide monitors. For example, you can position 4 pictures in 1 row and 4 columns to occupy all those ultra-wide pixels and in the next slide have 5 pictures placed in 2 rows and 3 columns instead of using the same 4 columns and viewing 4 pictures in the first row and only 1 picture in the second row.
You can add some space between the photos using the controls inside the [ Spacing ] section. Having different amounts of horizontal and vertical space can be used, for example, to place some text between the photo rows while having minimum or no space at all between the photo columns.
It's also possible to place photos that do not occupy all available space in random positions inside that available space using the controls inside the [ Small media files ] section. Simply check the [ Position a media file randomly if it occupies less than ] box and select the percentage. The algorithm is the following: if the photo is less than the selected percentage tall, it will be moved to a random number of pixels vertically from the center. If the photo is less than the selected percentage wide, it will be moved to a random number of pixels horizontally from the center. The photo can be moved in both directions if it's not tall enough and not wide enough at the same time. Random photo positioning is only available if you select the [ Do not enlarge (show in original size) ] option in the [ Viewer ] tab, [ Picture resize ] section.