Unless they specifically tell you when you check in that you will only get to shoot for 15 minutes. (which I assume would happen)Yeah, it matters. If you got there and they let you check in at 5:15 and shut the lights out at 5:30, would you not be upset? After all, you are paying for 30-minutes. Just because YOU are saying that you are willing to pay doesn't mean that I am. If they let me sign in at 5:15, I would believe they would honor the 30-minutes that I paid for.