I ended up rejiggering the pinhole on this. Rather than risk the pinhole I drilled through the plastic cap being less than optimal, I drilled it out with a larger hole and covered it with a square of aluminum from a pop can. Gorilla Glue to the rescue, yet again. Once that dried, I put a hole through the aluminum with a straight pin.
But what is the diameter of a straight pin? 0.0255 of an inch as best I can tell, call it 0.025 or 0.635 millimeters.
Now what? To properly expose the film, I need to calculate what f-stop results from that size hole and the focal length of this monstrosity. The focal length looks to be 1.75 inches.
Working from the helpful forms and calculations here, it looks like this camera has an effective f-stop of 70.
So, not too bad. The exposures won’t be too long. This chart displays times as long as 22 hours. That’s not too practical.
The camera is done. Time to see what it can do. I am tempted to use some color film just for testing purposes, but I don’t have any to hand. Perhaps one of these old rolls of Ilford Delta 100 will serve.