In past years my eyes and brain have accepted a 3:2 aspect ratio for photos is “normal” – whatever that means. But here of late, shooting with my Canon S90 and now my Olympus E-M5, I’ve been shooting at a 4:3 aspect, often composing with a 3:2 finished product in mind, so as to use all of the smaller sensor — then cropping the images to 3:2 during post-processing.