Well, why bother? Simply import the images directly in AE after having set the still duration in the import prefs to 15 secs. Then simply drag&drop them onto the new comp icon and once you have all your pre-comps, drag&drop them onto the icon and in the upcoming dialog let the program sequence them or use the sequence layers keyframe assistant. You're making things way too complicated...
I understand what you said...just take out the step of putting them into premiere pro first and create 15 second comps in AE. Thank you. That is what I will do. CAn you tell me how to trim up the length of the comp in AE the way I have done it so thecomps are only 15 seconds and not the duration of theentire set of images.
Since time is the same for every image, go to Comp Settings and at the bottom you can specify the length of your composition. But Myl has informed you correctly. In the Timeline you can also drag the handle at the end of each image back to 15 seconds.