Any kind of recipient can be transformed to a camera. The only things we will need are:

  • Paint the interior in black, is better if it’s a matte finish paint.
  • Make a pinhole. Try to do it in the centre of the container. We need to keep it closed until the moment you want to take the picture.
  • Place a photosensitive material to capture the light. We would normally place it in front of the pinhole. You can use photographic paper (is better if it’s matte) or film.
  • Sile the recipient from the light. Black tape will be your ally in this step.

In order for the image to be in focus, we need to adjust the diameter of the pinhole to the focal distance (F).

The focal distance is the distance between the pinhole and the photosensitive material.

 

EstenopoTo calculate the diameter of the pinhole we use the next formula.

Formula D

To adjust the diameter of the pinhole we take as guide this table of needle diameters.

Nº pin 4 5 6 7 8 9 10 11 12 13 14 16
Diameter (mm) 0,90 0,80 0,73 0,66 0,58 0,51 0,46 0,40 0,35 0,33 0,30 0,25

The material where we will do the pinhole must be less thick than the diameter of the hole. A good material to do them on is the yogurt covers.

Once we know the diameter of our pinhole, we can know our diaphragm (f).

f=F(mm)/D

Knowing the diaphragm and the sensibility of the photosensitive material we can calculate with a photometer (or a camera with photometer) the exposition time.