So I am going to be photographing in a church soon with okay lighting and need some advice on what film speed to use. I am using a canon sureshot 60 zoom as the camera, and will likely use no flash as the flash on the sureshot is terrible. In terms of film, I am considering Kodak Portra 800. How grainy is Portra 800? Should I just use Ultramax 400, or would that be more grainy?