Im looking for an umbrella to use for my SB600 that im starting to use off-camera. I assume I would need a somewhat smaller umbrella to amplify the light more since its not as powerful as say an alien bees. Also im not sure if I should be getting a silver one with a black back or maybe a convertible white/black umbrella. That way I can shoot through it, but im not sure if the SB600 provides enough light to be able to do any good shooting through an umbrella. Please give me any advice you can, or maybe even some photos with a setup similiar to this to see what can be done.