Great looking battle scene, but like pied said, make sure to use a solid bckground, and focus the camera (which I still need help on doing to) to really make the moc pop :)
I like how the ballista turned out and the fire effect, but some of the pics are bluury and hard to see and I kept getting distracted by that awesome Death Star! A couple quick suggestions about things I've picked up over time: Your camera should have a Macro setting for taking close up pics. Learn all the functions of your camera. A great MOC is lost if no one can see it. Also, use a neutral backdrop like a sheet, or something. That way all the attention is on your MOC. Keep building and improving those pics. Oh, by the way, who ended up getting the goblet?