filing box pinhole camera

i've wanted to build a pinhole camera out of an object that was manufactured by a company and not hand made by me. i went to fred meyers and looked through their storage section and found a 9x11ish plastic filing box. it was already black inside and seems to be opaque enough. here's what i started with.



this was way more simple than i was originally planning, i'm not complaining just a little shocked i guess. i went through and taped up all the areas that were or seemed like they would leak light. again, very easy and there were not many places that need taping.



i had to cut a hole for the pinhole. the plastic was fairly soft so it was easily done with an exact-o knife. i just measured half way from the top and bottom, and from the left to right.



i'm going to be using 4x5 film in this camera, so i cut a piece of cardboard the same size as a negative holder that fits 4-4x5 pieces of film. then i glued the negative holder on to the cardboard. this way i can just load the film into the holder and tape the cardboard on the inside back of the camera/ box.
after all my years of making pinhole cameras, i never once thought of doing this until i learned about warren harold. i recently feel in love with his work, so i thought i would give his process a try.

so here's the specs for this camera:
focal length: 9 in.
pinhole diameter: .021 in. (i want this camera to be a little blurry, so the p.d and f.l don't really match up)
f/ stop: 431