I am just beginning to experiment with strobe light. I am doing outdoor photos of my wife and am using a Sunpak PZ42x through a 43" white westcott umbrella. I am looking for general tips and had a few specific questions. 1 - should I leave the flash at full power and just move the stand closer or subject closer/farther? 2 - what Zoom should I have my flash at? ( lower like 13mm or higher like 70mm ? ) I do have a second flash and trigger, so I may try two flashes, but am hoping to just use one for now and get used to that before going further. Thanks for the advice guys.