Metal and glass, its all about the reflections - and to hold focus you may need to go from f/8 to f/16 or even f/22, so a bunch of light too. I've shot larger pieces like this by shooting through a hole in some foam board and surrounding the subject with as much white as possible. A few 4x6 foot panels getting full flash power sure helped. BTW - With speedlights there is probably no reason to shoot at 1/10th, a safe 1/250th (or better) can avoid slight blur from mirror shake etc (assuming it is not locked up).


BTW - I actually just bought a 4th 580exII just to deal with some metallic subjects,.. set that room a light! and good luck.


-Shea