pinhole cameras

To start my pinhole camera I started by choosing a suitable box, for my camera I used a "Jaffa cake" tube. To start I cut out a rectangular hole and painted the inside of my tube black to stop any light reflecting inside the tube and waited for the paint to dry. Once the paint was dry I put a strip of foil over the hole I had cut out and gaffa taped it on round the edges to stop any light getting in, then I put a pinhole through the foil.  After this I made a flap that will cover up the hole until I'm ready to take the picture, by doing this it stops any light getting in before I want it to. I had to then make a formula which tells me how long I will need to expose it when taking a picture.
The formula is:
Focal stop= Distance from pinhole to paper / diameter of pinhole
Focal stop = 65/0.8= 81.25
Exposure time: three and a half minutes inside and 30 seconds outside.
When all this was complete I took my camera in to the dark room to load up with photographic paper, then I chose a location to go to, put the camera on a sturdy surface and opened the flap for the right exposure time then shut the flap and took the camera back up to the dark room.
Once I was back at the dark room I got some tongs and took out he photographic paper from my camera and put it in the developer for 30 seconds, I then took it out and put it in water for 10 seconds then placed it in the fix for 30 seconds. Then I took it out and put it in a tray and took back out in to the light to see if it was any good, if it was good I took it back in to the darkroom and put it back in the fix for 5 minutes and then the water for 5 minutes. My picture was now ready to be dried so I put it through the dryer. Now I have a pinhole picture.