This is a trick to take pinhole photos with a Bronica SQ-A by creating a pinhole and shutter
assembly on an SQ body cap. We targeted Worldwide Pinhole Photography Day, April 29, 2007.

View the final results.

Fortunately we started early, Rev 1 definitely missed the mark a bit. But now we present Rev 2! A number of the existing parts were reworked to expand the bores of various apertures. The shutter itself had to be reworked for size and throw. Making lemonade out of lemons, we took advantage of this rework to make the shutter base plate a mirror image of the previous one. That permitted ditching the kludgey lever for tripping the camera shutter button (an operation necessary to make the camera think it took a picture, thereby allowing the film to advance).

Making a note for 2008 -- it might be cool to replace the sunshade and clamping washer with a machined filter step-up ring. That would allow not only fitting a sunshade, but also filters. Although with the three stop filter factor of a 25A, I might need a lounge chair as part of my gear. :)

The test pix below used the 0.014 inch (0.36 mm) f253 pinhole plate from the Rev 1 tests.

(Yes, technically, it is an SQ-A, but suffixing that with "hole" doesn't carry the right cachet.)

A CAUTIONARY NOTE! Recently, after a short round of pinhole and regular shots, I began having trouble with this SQ-A body using the regular lens. The shutter would only fire from the button and not from a cable release. I don't know whether "dry firing" without a lens coupled to the shutter mechanism can induce problems or not. I have obtained another body that is working, but think I will not use the SQ-Hole attachment on it.

So --- anyone enamored of what I did here should consider themselves forewarned.