I set my camera on manual 75% of the time, I find the auto exposure to be inaccurate and artistically bland, I have more creative ability knowing and using exposure to my advantage when taking photos. My Grandfather passed along to me his 1950's Rolleiflex and on the back is a perfect guide or cheat sheet to getting a great exposure.
A.P. is always near by watching me when it comes to cameras and gadgets, can you spot him in the pic above.
ISO/ASA/BS - the American Standards Association (ASA), and British Standards (BS); the newest term, ISO, all