Changing std crop areas

I am working on with Fotografie and trying to get a local site operational before going "live". I love the theme but one feature is driving me nuts! The 1:1 aspect ration of "featured images" on the All Posts page is excellent - but it is a crop of the "featured image" on the individual Post page. That is displayed with an aspect of 2:1. If I edit the image to get a good square image on the Post summary, the 2:1 crop on the individual page chops off the upper portion of the photo. [Or vice versa if I focus on the individual page]. Is there any way to modify the selection - or do I need to go into the Uploads directory in wp-content and individually crop/modify each of the stored images? Not an inviting option for the long run.