- Go to menu Images › Stacks › Tools › Animation options…
- In the dialog, set the desired frames per second, or “Speed”.
- Select the stack to save, and go to menu File › Save As › Animated Gif …
PS. in order to include overlays in the animated gif, such as ROI or scale bar overlays, these must first be converted to pixel data by flattening the image.
- Go to menu Image › Overlay › Flatten
or use ⌃ Ctrl / ⌘ ⌃ Ctrl on a PC ⌘ command on a Mac + ⇧ Shift + F.