What is the fascination of pinhole cameras? For me, I think there are two main reasons.
Firstly, the pinhole camera yields an image which has unique characteristics. To begin with there is no depth of field - or, more accurately, the image has an almost uniform degree of sharpness (or unsharpness) across the entire depth of the scene. Also, because the aperture of the pinhole camera is small, exposures tend to be much longer than with conventional photography. In that sense, the pinhole photograph encompasses a longer timescale than usual and can give images beyond the normal scale of vision.
Secondly, pinhole cameras are often low technology and the scope for construction, out of almost anything to hand, adds another level to the creative process. Not being tied to a mass-produced camera body allows for all sorts of perspective distortions for expressive ends. I have made pinhole cameras out of Pringles boxes, show boxes, an old box file, 35mm film canisters as well as making a panoramic camera with a circular film path. More recently I have fitted pinholes on to digital cameras.