Nice article, and impressive sample pictures. Now I want someone to write an article about a low-cost sensor that I could use to turn this into a digital pin-hole camera!
With an interchangeable lens camera, a lens cap with a hole drilled in the center is a cheap approach. There are "precision" pre-drilled lens caps available for purchase. Machining provides a potentially wider angle of view, but with a digital sensor this isnt likely to be as much of an issue as with film...even at the high end, medium format digital backs currently top out at 645 format while 6x17 is not unusual for 120 film systems.
It's not difficult. You need a camera and a pinhole. With my Speed Graphic, I tape some tinfoil over a lensboard and poke a hole in it with a pin. If you know roughly the size of the hole you can make a good enough estimate of the exposure time. Then it's basically point and shoot.
With a digital camera, a person could go out in bright sunlight, play with ISO and/or shutter speed, then calculate fstop using Sunny 16 and looking at histograms.
When I looked, most parts-house available sensors are small and even a 1" format sensors are pretty dear. MFT, APS-C, etc. were a multiple of a complete entry level interchangeable lens camera. For a pinhole camera with a small sensor, it's going to be hard to frame a specific subject because the sensor's field of view is tiny. Even a wire viewfinder will probably struggle with framing due to parallax. Basically the low cost sensor for pinhole photography is photo-chemical film.
A hacky alternative for a might be modifying a flatbed scanner. Just step the photo array slowly enough that there's reasonable exposure at each point. The good part is that a flatbed scanner is a stupid big sensor and there is some literature for hacking them. But for a pinhole, I'd expect the exposures to be rather long even for pinhole photography.
This makes me want to go build one, that looks so cool! More related to computers, I remember someone telling me that video games before depth of field were essentially rendering games from the point of view of a pinhole camera (i.e. everything is in focus and the camera is just a point)
This is an awfully fancy pinhole camera. When I took a photography class we all built them by taping a piece of film to the lid of an empty oatmeal tin and poking a hole in the other end.
It was shoeboxes for us. Also, remember 126 cartridges? When I was a kid, we'd make little cardboard boxes that fit over the film area, with a pinhole in the front, held together with rubber bands, and film advance with a popsicle stick. This is sort of the whole point of pinhole, crude and sloppy.
In the US, 35mm film is still widely available as general merchandise in chain stores. 120 (medium format) is available in most camera shops (though camera shops are increasingly less common). Large format 4x5 may or may not be available in a camera shop. All of it is available over the internet. Most pinhole cameras are medium format or large format because a tripod is required anyway so the convenience of 35mm is pretty much lost.
Between B/W and Color, C41 color negative development is still widely available. E6 color transparancy, i.e. slide film is less common. B/W is also a specialty development service, but it's the easiest to do yourself but non-trivial. The internet is again an option.
