Somehow I find that hooking a lens cap pinhole onto an expensive digital camera just ain't into the spirit of things.
Atta, boy! Now you're talking!

Yup, those fancy lens caps seem to be all the rage over at that place called get a lens cap, drill a hole (or fit a laser-cut pinhole from eBay) and away you go. Trouble is, pinholes are a world apart from auto-everything, computer-dependent digital: the results you achieve with a camera obscura first made famous by Leonardo in the Tower of Winds are a statement of artistic visual expression using one of the most primitive photographic instruments available. As they say of pinholes, "out of nothing, comes something. And then some."

AND, prey tell: why is the Zero Image "hopeless in [your] hands"? Mr Au would be appalled. Nobody has ever said that before. The Zero (any which one of them you use) works best if you have a fluid understanding of metering and exposure interpolation, film response, flexible visual styles (and restrictions e.g.the camera's extreme DoF and how to employ it with your subject). Don't let it gather dust! I had a riotous ball today with a Goth in a country graveyard.