Today we’e welcoming Todd Schlemmer into the fold with his review (preview?) of the terraPin “Snappa”, a 35mm pinhole film camera prototype he designed and 3D printed; and the latest in a long line of creations by this master of 3D printing.

Over to you, Todd.

This camera, which I call the “Snappa”, is a direct descendant of the many pinhole cameras I have designed, built, and shared. Here’s what’s covered in this review:

Most of my pinhole cameras are designed around various 120 formats — It’s a great medium for pinhole, with big luscious frames and a lot of flexibility. However, I hear from people all over the world who would like to build one of my cameras that they have no idea where to get 120 film. Luckily, almost everyone with an interest in photography can find 135 (35mm) film and this is where the Snappa comes in.

Origin and evolution

My very first 3D printed camera was the 135 PINHE4D, an ugly beast that made some great photographs. The failings of this camera have had me mulling the evolution of my next 135 pinhole for a few years now and as they say, no time like the present.

Some of the things that bothered me about the PINHE4D were:

  • Clunky design – The removable back was a quick and dirty solution that required rubber bands to hold it closed.
  • Difficult to print – Overhangs and “bridging” are difficult for some 3D printers to handle well.
  • Frame indexing – Unlike 120 film, 135 film is normally indexed by a cog that engages the sprockets. Eight sprocket holes is a 36mm-wide frame, and modern 35mm cameras won’t let you over-wind.
  • Horrible styling – I want people to like using my cameras, so their look and feel is important.

The terraPin Snappa improves on the PINHE4D in a number of ways:

There is an indexing cog that turns 180 degrees for every frame advanced. This allows for very precise indexing of standard frames. This indexer is a nice feature but it does add complexity to the design, and will be an option when I release the files.

Over the years, I have gotten better at designing light-tight 3D printed boxes, and the Snappa benefits with a tight flush-fit back. That said, the Snappa has no special printing requirements, and should fit on even the smallest 3D printers.

Lastly, it has flat faces front and back, which allows for easy glue-on decoration and customization — a trick I borrow from my friend and fellow pinhole photographer, Jeff McConnell.

There are a couple of things I need to sort out before I publicly share the Snappa — the “rewind knob” isn’t captive and could (but hasn’t yet!) fall out and maybe cause a light leak.

Also, the back is held on by sliding clips that work well, but add a bit of clunk to the camera. Small things maybe, but small things ruin photographs every day.


Technically, the Snappa stacks up as follows:

Approximate focal length: 27mm
Pinhole diameter: 0.23mm
Aperture: f/117

I have a pinhole photography workflow that begins with the camera. A pinhole camera (usually) has a single aperture and f-stop. Even though a pinhole cannot focus light, when I design my cameras in CAD (Computer Aided Design) software, I can specify exactly how far the pinhole will be situated from the film (the so-called “Focal Distance”).

Furthermore, knowing how far the pinhole will be from the film plane allows to me specify an appropriate pinhole diameter based on some simple math. The FD divided by the aperture diameter gives me the f-number of the camera.

When I build my cameras, I use a calibrated needle-awl to “drill” the pinhole, and then check and measure the resulting aperture with a digital microscope. Armed with these measurements, I can then make an exposure chart with reciprocity failure adjustments for my selected films (more on that below).

I meter every shot and don’t waste my time calculating the exposure in the field. I also won’t shoot a new film unless I can find some kind of RF data for it.

As a camera designer, I feel an obligation to prove that the camera works as advertised, and the first few rolls of film are intended to demonstrate good exposures over artistic expression.

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For the purposes of testing, I prefer a heavy tripod and longer exposures to minimize blur from shutter and camera movement.

The irony is that I hope my technically competent photographs are also visually compelling to someone who imagines they might 3D print and assemble a pinhole camera – possibly their first.

Testing the Snappa

To test the Snappa, I chose a roll each of Kodak Ektar 100 and Fujifilm Neopan Acros 100; one color and one black and white negative film, respectively.

I have a lot of experience shooting pinhole with these films and I trust the exposures I make with them. Long exposures (like pinhole) often require additional time for proper exposure, a property of film called “reciprocity failure” (RF). Every film has a unique RF curve, and I try to be diligent in metering and calculating my exposures.

To test the Snappa, I stuck it into my smallest sling-style camera bag, along with my Gorillapod, light meter and exposure chart. I carried it around for a few days and shot two rolls in a variety of locations. As I mentioned, I prefer a heavy tripod and the Gorillapod really must be wrapped around something sturdy for best results. Otherwise, long exposures and/or a very gentle touch are necessary.

I started with the Ektar and made a number of shots at the St. Demetrios Greek festival in the Montlake neighborhood. Every September, the church sells calamari, gyro, and retsina to hungry, but patient crowds.

I walked the dog with the camera, stopping to make a few pinhole snaps. I found myself down at the marina, and made a seascape. Later, a playground offered some demonstrations of infinite depth of field, and while at work, I shot a backboard rainbow outside the hospital. A visit to the cemetery, some fall foliage and finally I made a couple selfies outside the drugstore where I dropped off the color roll.

I foresee many new pinhole photographers shooting 135 and then taking it to a pharmacy for processing. I decided to test this, in lieu of my usual photo lab. They were out of some photo chemicals and told me upfront about the delay in processing. They gave me a discount for the inconvenience, but it would have much faster to use Moon Photo.

In the end, the negatives and scans were acceptable, and if I had no other option, I’d be satisfied.

After the Ektar roll, I loaded the Acros B&W and lugged Snappa No.1 around for a day. I shot on an errand to Harborview Hospital, and a walk through Seattle’s Ballard Neighborhood.

I organize regular pinhole photography meet-ups, and also brought the Snappa along with me. We went to the UW campus in Seattle and I made a number of shots around the campus. I finished up the roll at Woodland Park Zoo, shooting some quick scenes outside the fence as the autumn light faded.

Final thoughts

All in all, the Snappa has a place in the Schlaboratory collection of pinhole camera – which is something I cannot say about all of my experiments – and I look forward to refining the last couple of issues I think remain unresolved. 

I am delighted with the indexing cog and its precision, and I think that will make using “drugstore film processing” easier.  Given, however, that a 36 exposure roll of 135 has plenty of film to waste on overwinding, I am not sure the cleverness of a cogged wheel merits the complexity of 3D printing and assembling it.

The photographers must weigh in! 

In my 135 pinhole exploits, I have found that 36 exposures is a slogging exercise in delaying gratification, as I am more used to having only 12 or 16 exposures in my 120 film cameras. 

I may also design a revision that is as simple as possible, something like a 3D printed matchbox camera.  Even though 135 is not my favored format, I think there is a lot of room to utilize the convenience of the format, and I look forward to seeing others leverage the advantages of 135 in cameras I have designed.

The best part of this crazy science fiction hobby is seeing people create art with my tools. Stay tuned for further developments, and I truly enjoy hearing from people who have ideas or feedback.  

~ Todd Schlemmer

Note: Moon Photo processed and scanned this roll.

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  1. good job on this one, Todd! I’m sure many peeps will be happy to see this come to fruition. and if nothing else, 35mm is great as a stepping stone to get more people into pinhole photography with larger formats B-)