Dr Alastair Weakley:

Just spent ages trying to work out why my view didn't work. The error message said that the 'picture' attribute had no file attached to it. I thought because my model's ImageFile field had blank=True then it should be allowed to be empty. That's the case, but what was causing the error was my template code {{object.picture}} or something like that requires that there is a file. This is where I found the solution