04 Check your stacks
To make sure the right images are stacked, you can close all your stacks at once, either using the Stacks menu or with this toolbar button (available if you customise the toolbar). Each stack becomes a single thumbnail (the first image in the stack) with the number of images in the stack displayed in the thumbnail’s top left corner. You can click this number to open the stack, and click it again to close it.
05 Change your key image
But what if you don’t like the image used for the stack thumbnail? It might not be representative of the whole sequence, or it might be badly composed or exposed. There are a couple of ways to change this key image, and here’s one – just open the stack and drag the new key image to the front.
Aperture’s stacking system is simple and intuitive and incredibly useful… and with the auto-stack feature, Aperture does all the work for you!
See also
More Aperture tutorials