This is definitely a question better suited to a photography forum, however I'd rather be active on cinematography.com as I find it one of the best forums in terms of the community feel it has.
I recently invested in an old Pentax Super ME 35mm camera, and was just wondering if someone could shed some light on what the little switch to the left of the lens mount does? You can pull it down, and then it slowly ticks back into the start position. Is it some kind of self timer?