I have dabbled in large format somewhat and have owned three 4x5 cameras including the Crown Graphic I bought yesterday. This one came with a medium format roll back, which I have never used before. I obviously thought it would be empty when I was looking at the camera but when I cracked it open to look inside there was a full roll of film. It couldn't have been open for more than a second and I know this will cause exposure but I am wondering about the film that was still protected by the roll and if it might still be viable. Also, how can I tell if I am at the beginning or end of the roll and how to unload it safely. Any thoughts or links to info?