Font size photo presentation

Where can I set the font size for captions in the photo presentation?

If using Kookaburra, in the page template under either Slideshow or Single-image pages > Captions.

If using Pangolin, you’ll need custom css.

for the slideshow presentation:

.fancybox-caption__body {
  font-size: 18px;
}

For the single-image pages, try:

.single_image figcaption {
  font-size: 18px; 
}

You may want to use em: font-size:1.2em; See CSS Font Size

Thanks