1610HD

Hello

I have a question. I just got a projector 1610HD and i have it mounted on the ceiling about 23 feet from the screen. I would like to know how to get it where the picture is right on the screen, right now it is bleeding off the screen. My connection is HDMI, Is there a setting where i can change the size of the picture? Since all screens are different sizes i would like to know how to do this