How To Shoot Reflective Objects

Learn from Director Of Academy Andrew Boey on how to shoot reflective objects by using his famous Lighters’ Cheat Sheet Formula:
Hot-shoe Flash set at 1/8 power, with ISO200 on camera:
Flash 2 feet away from subject = F16
Flash 3 feet away from subject = F11
Flash 4 feet away from subject = F8
Flash 5 feet away from subject = F8 (bcos of Inverse Squared Law, remember??)

However, if you use a flag or an umbrella, you will lose 2 stops, making it:
Flash 2 feet away from subject = F8
Flash 3 feet away from subject = F5.6
Flash 4 feet away from subject = F4
Flash 5 feet away from subject = F4