What are the differences in one vs. the other? I'm considering a shoot-through umbrella or a softbox. Of course I know softboxes come in different sizes, but in general, is there an obvious difference in the final product? I'm using an SB-800 as the light source (and would use softboxes which are designed for this). So I'm just curious as to the difference between using a softbox or a shoot-through umbrella.