Selection before technique

As with a moodboard, the first rule is: select strictly. A slideshow of 25 strong images in a sensible order is more captivating than one of 120 thrown together. A narrative order (arrival → highlights → farewell for a trip; or chronological for a party) gives the slideshow a thread. Cull ruthlessly from the photo pile before you start.

Format and resolution

The target medium sets the format:

  • TV, YouTube, projector: 1080p landscape (1920 × 1080, 16:9).
  • Stories, Reels, TikTok: portrait 1080 × 1920 (9:16).
  • Square feed post: 1080 × 1080 (1:1).

The individual photos should be at least as large as the target resolution, so nothing has to be upscaled and blurred. Downscaling from 4K for a 1080p slideshow is no problem; upscaling from a small web image looks bad.

The calm trick: uniform sizes

The most common annoyance of shaky slideshows: photos with different aspect ratios. In a 16:9 video, portrait photos are either shown with bars or cropped — and when that happens inconsistently, the image jumps. Two solutions:

  • Bring them to a uniform format first (see Make multiple images the same size) so all sit the same.
  • Deliberately use a soft background: portrait photos in front of a blurred, format-filling version of themselves — that elegantly hides the bars.

Without an extra app: the built-in tools

  • iPhone: the Photos app builds Memory videos with music automatically from an album; they can be edited and exported.
  • Google Photos: under "Create" it offers movies/animations from selected images.
  • On the computer: presentation programs (PowerPoint, Keynote) can export slides with images and transitions as a video — an underrated, ad-free route.

Timing and music

3–5 seconds per image is the proven guideline. Soft transitions (cross-fades) feel calmer than hard cuts. With music it helps to roughly set the image changes to the beat — that gives the slideshow rhythm. Less is more here too: a tight, well-timed slideshow sticks in memory; an overlong one tires.

In short

  • Select strictly and order narratively.
  • Match format to the target — 16:9, 9:16, or 1:1.
  • Uniform sizes keep the slideshow from jumping.
  • 3–5 s per image, soft transitions, music to the beat.