Silverbased

In a pair earlier of articles, I showed how to gut a cheapie focus-free 35mm trashcam, and replace its lens with a pinhole.

One rationale for that project was that nowadays, it’s getting harder to buy and develop any film size besides 35mm. Pinhole cameras made for other odd formats are certainly fun, but sometimes require access to a darkroom to make them practical.

But one of the joys of pinhole photography is being able to try out bizarre, idiosyncratic camera designs: Weird-shaped frames, ultra-wide-angle coverage, or warped perspectives from curving the film plane.

The moderately wide coverage of the normal plasticam pinhole is interesting; and its standard 24×36mm frame makes developing the film at any lab easy. Yet compared to more exotic possibilities, it does begin to seem a little tame…

A Japanese woman on Flickr wanted to make a panorama-format pinhole camera. Her inspired idea was to take a plastic Holga, and saw it into pieces. She reused its film-supply and take-up-spool compartments, but replaced the middle section with a homemade “stretch limo” version: A light-tight box with film gate, pinhole and shutter. Genius!

A Holga uses 120 film of course; but she inspired me to consider doing something similar with 35mm film. (Aside from getting interesting widescreen framing, with pinhole cameras a larger format helps give a more detailed image.)

The way I build a 35mm plasti-pinhole, the original shutter is discarded; so it’s not the button on top that takes the picture any more. But the film-winding mechanism remains intact. As you wind, a toothed wheel allows 8 sprocket holes to go past, then locks; this yields the standard-width frame spacing. You still need to click the button on top to release the winding thumbwheel, before you can advance to the next frame.

But you do this independently from making the exposure. And I had an “aha” moment when I realized that if you clicked and wound twice between pictures, that standard mechanism would permit shooting double-width images: 24 x 72 mm!

But how to build the rest of the camera?

Here is my whimsically warped solution: I took two identical plastic trashcams, and sawed through them, exactly at the edges of their film gates. Then I glued and taped them back together “siamese-twin” style, to make a panoramic pinhole camera.

Two focus-free plastic 35mm cameras; $1.40 for the pair at my local thrift store.

A majority of trashy plastic models use curved film gates, to mask the deficiencies of their crummy lenses. But for this purpose, finding two matching cameras with flat film gates makes construction much simpler.

Some plasticams have their own “panorama” mask which you can swing into place. But all those extra parts would add more complications, so I shunned that style too. These two ultra-simple Bell & Howell trashcams turned out to be perfect.

I arbitrarily chose one camera for the supply-compartment half, and the other for the film takeup side. Then I disassembled both cameras and discarded all the unnecessary bits and pieces inside—lenses, shutters, springs, etc. It’s important to remove all stray metal parts before sawing into the camera body!

Discarding useless innards; black lines mark the approximate cut locations

Unlike in my standard plasticam-pinhole, I could not reuse the sliding lens guards as a shutter: The pinhole opening would not be aligned with either camera’s original lens position. So all those moving parts got tossed too.

Next I screwed the shells back onto the camera bodies, wrapped tape around both to hold their backs shut, and sawed through each one.

The crapcam types shown here include dummy weights glued into their bases (to lend an illusion of quality!) It was particularly tricky to avoid grinding the saw blade into those metal chunks—so be careful. An old hand-saw miter box is a great tool for getting a straight, square cut.

I sawed just inside the right edge of one camera’s film gate, and the left edge of the other. This still left some interior partitions standing in the way of the desired pinhole location, all of which needed to be cut away with a sharp knife.

Now, I wish I could say I used some sophisticated assembly technique to combine the two bodies. But really I just spooged the halves together with copious amounts of black silicone sealant—supplemented with much electrical tape. I was trying to fill all gaps where light might leak in, and keep the now-combined film gates as well-aligned as possible.

I also glued an aluminum bar across the two film-door halves, so the back would swing open and latch shut correctly as a single unit again.

A piece of aluminum sheet with an 0.2 mm pinhole went across the front of the camera body. Positioned only 26mm from the film plane, I knew this camera was going to give some wide-angle coverage! (Horizontally, it’s about 110°.) The pinhole size works out to f/128, for those of you keeping track.

For this camera I tried a new shutter idea, a design which has quickly became my absolute favorite. I will definitely be using it again for any future pinhole cameras.

I took a spare cable release I had lying around, and cut away the rotating barrel intended to thread into a shutter button. This uncovers enough extra length of the moving shaft to allow me to hot-glue it to a piece of thick black cardboard. Then the cable sheath is glued to the front of the camera body.

The moving shutter piece is outlined in red here. It has a cut-out which uncovers the pinhole as the cable release is pressed. A couple of scrap pieces glued around the edges guide the moving panel.

What’s wonderful about this design is that the cable-release’s own internal spring snaps the shutter closed again—or, it can be locked open indefinitely with the set-screw of the release. And there’s no jiggling the camera when you open the shutter.

The front shell of the camera needed a matching rectangular opening cut into it. Then finally, I screwed and taped the camera shell back together again. (There’s no particular significance to the metallic tape—it just hides several no-longer-needed openings in the camera’s front panel.)

The block of particle-board contains my usual homebrew tripod socket: A 1/4-20 nut epoxied into a hole in the bottom.

For a while I was jokingly calling this camera the “HaxPan,” in reference to Hasselblad’s multi-thousand-dollar panoramic XPan camera system. Of course, my camera covers a wider angle than even its 30mm lens (as well as saving a few pennies… )

Obviously no ordinary lab will know how to make prints from these crazy non-standard frames. But the negatives can be developed just like any other 35mm, and then scanned on any of the current inexpensive flatbed film scanners for further processing.

Making this camera was truly an experiment. There are still a couple of small light leaks at the joint between the cameras. And next time I would probably do a few things a little differently…

Placing the pinhole so close to the film does give extremely wide views—but you can’t see much detail at the edges, because the light fall-off is so extreme. And a 110° angle of coverage is so hard to visualize without a proper viewfinder that I found framing to be quite hit-or-miss.

So next time, rather than placing the pinhole so far back, I would build up the light-tight inner compartment a little deeper and use a slightly longer focal length.

But that’s the great thing about pinhole cameras: The cost of experimenting is low… and the fun of blazing new ground is priceless.

Happy hacking!

Sample photo from the double-width 35mm pinhole. Note small light leaks at the seam between camera bodies. More samples here.