What pinhole photography is and how it works can be learned easily by browsing the many sites that are available on the web. Here I'd like to tell you about how I started with experimental photography.
There are 4 ways:
1.) You can buy a pinhole camera ready to go. E-bay and other internet vendors often list such brands as “Holga” or “Diana”. Such cameras are not too expensive. Whether they're worth it is another question since the bodies are made of cheap plastic and more often than not you have to use sealing tape to avoid light leaks.
2.) You can buy or make a pinhole attachment for any type of SLR camera. This is a good way to start. Instead of the lens, you install a drilled body cap outfitted with a small (and centered) pinhole in thin brass foil. Unfortunately, not all pinhole effects, such as ultra-wide viewing angles, can be explored with this technique.
3.) Given sufficient know-how and skill, you can turn any camera into a pinhole camera. The best cameras to start with are the not-too-sophisticated 120 roll film types from the 1970's or 80's such as the Agfa Click, Agfa Clack, Pouva Start, Druh, Ami 66 or the Russian Ljubitel. Such cameras can be modified in many ways including changing the focal lengths. Shorter focal lengths are the easiest ways to create fish eye lens effects.
4.) Finally, if you'd like to do it all yourself, you can build your own camera from scratch. Don't worry. It's not complicated!
I started with a 0,8 mm pinhole. The basic rule is: the bigger the pinhole, the blurrier the image. The smaller the pinhole, the sharper (but darker) the image. You can drill 0,8 to 0,6 mm pinholes using a sewing needle. If you require smaller pinholes, you will have to invest in professional mini-drill bits. I am currently using only 0,2 and 0,3 mm pinholes of my own manufacture. The photographs taken with my cameras are always sharp.
Pinhole diameter & exposure time.
Smaller pinhole diameters produce sharper images. But the exposure time is necessarily longer. My pinhole experiments have generally been in the 0,2 – 0,8 mm range. It is impossible to drill pinholes smaller than 0,2 mm mechanically; lasers are required to make smaller pinholes. The smallest sewing needles can be used for holes between 0,6 and 0,8 mm. Occasionally, mini-drills are available on E-bay for 0,6 to 0,3 diameters. To measure a pinhole made with a needle, scan it on a flatbed scanner and import it to Corel Draw. Once enlarged, the pinhole image can be measured exactly with the ruler tool.
Pinhole diameter 0,2 mm. Exposure time 3 min, Fuji Superia 200.
"I have not accounted for reciprocity failure (the so-called Schwarzschild effect) -- the huge under/over-exposure tolerances for negative films
Pinhole diameter 0,5 mm. Exposure time 8s, Fuji Superia 100
Pinhole diameter 0,8 mm. Exposure time 12 s, Fuji Superia 200