Pinhole camera constructionMake the inside of the selected box (preferably cylindrical) non-reflective, by painting the inside with dull and coarse black paint. The paint must be non reflective with rough texture. Alternatively you can make the box light proof and non-reflective by lining it with black paper. To make the box totally light proof cover the exterior with black paper. Make the lid also light proof by painting it black on both sides. It will be of advantage to make the pinhole at the closed end and photo paper loading arrangement at the other end. Now you have to make the pinhole and you can make it directly on the bottom of the box. If your box is of about 3 to 6 inches in length, you can get best effects with a pinhole of 0.013 inch diameter. You can do this in the following manner. Select and mark carefully the center of the inside bottom of the box. Make a hole with 10 size sewing needle and push it through the bottom material up to half of the needle shank. To get smooth and round hole keep rotating the needle as you make the hole. If the bottom is of metal, file the edges smooth with the help of fine sandpaper or file.
Make the pinhole as earlier explained with a sewing needle in a separate metal foil or black paper. Punch a hole of ½ inch or above on the center of the box bottom.
Tape the metal foil/black paper with pinhole over the center of the box bottom hole made earlier.
Now make a shutter to prevent light from entering the camera when you are not taking a photograph.
A flap of card board with the provision of tape hinge can be used as shutter. A small piece of tape can be used to keep the shutter closed.
Though you can use both film or fast photography paper for taking the image, it is preferable to use paper as it can be loaded into the camera under a safelight.
Depending upon the size of the lid choose the size of photo paper. You can trim the corners, if necessary, to make the photo paper fit in.
Now under safelight fix the photo paper to the inside of the lid with the help of a small piece of tape on the opposite corners.
Take care to keep the emulsion side of the paper facing the pinhole.
Cover the camera with the lid loaded with photo paper. Tape the edge with black tape to prevent light leaking in from the lid edge.
Required exposure time may vary anywhere between 2 - 8 minutes for photo paper (KODABROMIDE Paper, F2) depending upon the brightness of sunlight.
As the exposure time is longer care must be taken to fix the pinhole camera without movement during exposure.
Develop and print the photograph in the usual required manner for the photo paper.
With a few trials and errors you can find the required exposure time for your pinhole camera.
images courtesy: Ellywa, Douglas Whitaker