Upper Left: Program Mode, Flash on camera pointed at subject
Upper Right: Program Mode, Flash off camera pointed at subject
Lower Left: Aperture Priority, Flash off camera pointed at subject
Lower Right: Program Mode, Flash off camera pointed at wall

f/8, 1/40 sec at ISO 100 Equal
f/11, 1/20 sec at ISO 100 subject one stop under background
f/8, 1/80 sec at ISO 100 subject one stop over background
f/8, 1/160 at ISO 100 subject two stops over background