Acegikmo 0 Light Poster

I'm using the drawImage(); method in Graphics2D to draw my png images. However, I'd like to be able to render them with screen blending. If it's possible, I'd really like to know how you do it, and if it's fast enough to be used real-time in games.
I think I'm supposed to use g2d.setComposite():
But other than that, I have no idea.