Photograpy (pinhole)

This is another of my photos of Suffolk New College, its clear and you can even see a person sitting at one of the tables if you look really close !
Right at the back you can see alot of out lines of people walking around, i think its effective.
I had another two goes at taking photos both outside, but they both turned out to be blank, i could only figure out the right timing for inside the college (six minutes).
But it wasnt a nice day out side it was very dull so i never figured out the right timing !