[Plugin: BuddyPress Album] BP ALbum question about upgrade

I am using BP Album – 0.1.8.10 and I want to change Album Image Size. Now image size is 600px and I want to change to 800px. I have 24000 images in my database, my question is: What would happen with these images that are 600px when I change Album Image Size to 800px? Would they be same as it is or BP Album would enlarge them to 800px?

Option “Keep original image files” is disabled, so I only have these 600px and I don’t want to BP Album enalrge them to 800px. I want them to be 600px, and new ones to be 800px…

http://wordpress.org/extend/plugins/bp-album/