I've had this plywood 4"x5" pinhole box camera for years, and it was getting a bit long in the tooth, time for some upgrades.
First, there was a light leak around the top of the film holder slot, caused by some worn out black craft foam used as a light seal, and some black paint that had worn off the metal piece that serves as the main light seal for the raised ridge on the right edge of the film holder.
I took out the metal piece and repainted it with textured black spray paint. Then I removed the residue from the old craft foam along the top of the film holder area, sanded it down and reapplied fresh craft foam. I also sprayed more textured black paint to the groove where the film holder ridge fits into.
Another big change was in the way that the holders are held in place. This camera had originally used a removable view screen with a large removable viewing hole, and therefore used a system of rotating wooden discs as cams, along the top and bottom of the film holder, permitting a clear view of the screen. Since I rarely use the screen, preferring to use viewing dots instead, I removed the cams and in their place installed a 3/8" hardwood dowel.
I discovered that a sheet of black foam core board fits snugly between the dowel and a film holder, so that's the new method for securing the holders in place, using a rectangle of foam core board as a wedge.
Finally, I finished spraying the interior of the camera with black textured paint, there was an area along the front that I had left bare.
Here's an image of the rear of the camera showing the dowel and the newly painted surfaces:
Here's an image of the rear with the foam core plate installed:
And here's an image of the front of the camera with internal shutter in the open position. The brass acorn nut handle also functions as the front viewing dot:
I tested the camera today by exposing six Harman DPP prints, they all came out fine. After they dry I'll scan and post the results.
New life for an old camera, hopefully much more pin holing this year.
~Joe
PS: Poor quality photos via Hipstamatic on the iPad2 from the comfort of the man cave, cigar in hand.
PPS: I couldn't find my original post when I first made this camera (over on F295), otherwise I'd show you the old cam system. But you can see in the third photo the removable pinhole plate, secured by an oak frame and brass screws. The camera is 85mm focal length, f/285, about a 0.3mm pinhole in thin brass.
PPPS: The label "4.79" atop the camera is the conversion factor between f/128 and f/285. I meter the scene with my Gossen, reference the exposure time for f/128 on the meter (its highest f-stop) and multiple by the conversion factor to get the actual exposure time. The formula is: (285/128)^2, where 285 is the camera's focal ratio and 128 is the metered focal ratio.
