PINH5AD - a 4x5 inch Pinhole Camera
by schlem, published
The P5 is designed around a 4x5 film holder, widely available used or surplus. Film holders have a "dark slide" that protects unexposed film/paper from light, so the rubber band to close the shutter is not necessary (or desirable for long exposures). See exposure times note in instructions section.
Using the proven Pinhead shutter design, and lacking any film transport mechanism, the shutter blade is the only moving part.
NEW! 150mm extension available for "normal lens" exposures (not wide-angle, not telephoto) see: http://en.wikipedia.org/wiki/Normal_lens).
90mm focal length
designed for a 0.40mm pinhole
f-stop of f/225
70 degree horiz. field of view.
150mm focal length
designed for a 0.50mm pinhole
f-stop of f/300
46 degree horiz. field of view.
If you print a PINH5AD, message me, and I will send you some Pinhead stickers.
As always, more build pix available at:
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The mission is to share and promote open source cameras and related parts, created with CAD applications and 3D printing. Please join and post content!
-------- UPDATES since CAD illustrations --------
- viewfinders added for both extension lengths
- manifold issues in P5 Body fixed - please re-download corrected file if you have strange slicing behavior.
- opening on shutter plate resized to 4:5 rectangle to minimize very slight vignetting of 90mm field of view
- body reinforced at tripod mounting points to minimize possible lateral flexion / vibration
- corners of extension mount enlarged for thicker walls
- bottom added to small cavities in body for better bonding to film holder bracket
- inside perimeter of pinhole clamp enlarged for better fit
- 3D printed ground glass holder http://www.thingiverse.com/thing:267909
- Film Holder Clip added to hold holder/ground glass firmly against back of camera. Designed for rubber bands (elastics) or small bungies, and to not obscure the projected image on the ground glass.
Available at Shapeways in laser-sintered nylon:
This work is licensed under the Creative Commons - Attribution - Non-Commercial license. This license applies only to the files and documents available for download from the Thing Files section of this Thing.
All other related content (photographs, videos, and verbiage such as contained in "Description" or "Instructions" ) are excluded from this license. with all rights reserved, unless specifically available for download This notice constitutes a clarification, not a change, to licensing for this design.
I am printing this at 0.25mm layer height, 2 perimeters, 40% infill (tripod mounts at 70% infill) I found that two perimeters gave me consistent infill, ergo better strength, but 3 perimeters generated interior voids in some walls that might bend and crack. Cracks = light leaks = bad.
Print the following in black ABS or an OPAQUE PLA:
- film holder bracket
- PINH5AD body
- 90mm extension
- P5 small parts
Every part can be printed without support.
NOTE Complete 90mm and 150mm variants are available as zipped collections of parts. See "Thing Files"
You will also need:
- 4 - 3mm bolts, 16mm long and nuts (shutter)
- 4 - 3mm socket head bolts, 16mm long and nuts (tripod mounts) may be a tight fit
- Adhesive-backed BLACK velvet (http://www.rockler.com/product.cfm?page=9852)
- ABS glue of choice (I'm experimenting with a black plumbing glue)
- Loctite or similar for shutter bolt
- 2 X 1/4 inch (1/4 - 20) T-nuts (without prongs) for tripod mounts (glued in place) Alternately - 2 X 1/4-20 flanged nuts for use with modified tripod mount.
The P5 currently comes in two flavors:
a 90mm focal length, designed for a 0.40mm pinhole, with an f-stop of f/225, and a 70 degree angle of view.
And a 150mm focal length, designed for a 0.50mm pinhole, with an f-stop of f/300, with a 46 degree angle of view. Your pinhole diameter is not critical, and modern film has plenty of leeway for good exposure if your pinhole is not quite the "right" size. Additionally, there are now viewfinders for each focal length. They are designed to clip on top of the body of the camera for the landscape orientation. I need to add an additional clip so that they can be rotated if you opt to shoot in portrait. Coloring the inside edge of the larger box white will increase contrast and allow you to better sight your frame.
I originally designed a 66mm extension, which spaces the pinhole 90mm from the film plane in the film holder, recently added the longer option for a "normal lens" perspective. A chosen extension is intended to be glued in position, but I plan to design a clamping mechanism for interchangeable extensions, making for a more versatile camera system. I also plan to make a shorter (wide angle) extension. The base for the extension is 93mm x 116.5mm should you desire to make your own. The Pinhead Nose Assy can be used if you want to utilize the Pinhead pinhole mount and shutter parts. The framing in the body is sufficiently large for a 200mm focal length without vignetting.
At 70 degrees, the 90mm length is already a wide angle camera. A shorter extension (and consequently wider angle of view) has the potential for significant vignetting (corner cropping) at the shutter plate, and will necessitate a redesign of that part.
For bright light exposures, even with ASA 100 film (approx 1 second), the slight bit of vibration from opening and then subsequently closing the shutter can be enough to render your photo disappointingly blurry. Slower film (ASA 50 for instance, or a dramatically even slower print paper) would minimize this effect. I consider 2 seconds to be the fastest effective exposure time for pinholes without a remote shutter mechanism, and beautiful buttery images will result as you slow things down and shoot in more subdued light or with slower film/paper.
The largest part (camera body) is 143mm x 137.5mm (5.4 x 5.6 inches), which barely fits on a 6" x 6" bed with a peripheral skirt.
Assembly is straightforward (see pictures and diagrams):
The Film Holder Bracket is glued to the bottom of the Body (bottom surface to bottom surface, as printed), ALIGNING THE FRAME OPENINGS. I used black ABS pipe glue, pre-mounting the tripod mounts helped with alignment. Rubber bands and a wedge under the open end of the film holder made for a nice clamp while the glue dried. Careful - It's pretty goopy - the body has been redesigned to simplify assembly (larger gluing surfaces).
The fit of all parts is tight. Expect to sand/file the pinhole plate to fit into the extension. I find that a file is a good way to get a nice smooth edge and remove burrs without scratching the plastic. The nut traps in the nose of the extension are a tight fit and you will swear less if you trim them out with an Xacto knife prior to wedging tiny little 3mm nuts in the cavities. On a related note, fully fit and assemble the extension and shutter/pinhole assembly before you glue the extension into the body - there's a very small and remote chance the nut traps might break if forced. Would be a shame to have to print a new body too.
At present, the Extension is intended to be glued into the recessed opening on the top of the Body, orientation to your preference (removable clamp mechanism pending).
The outside surfaces of the bracket that carries the film holder should be lined with the self-adhesive velvet. It's fiddly, I know, but you will gain a very light-tight connection if you ensure that the velvet extends up the sides, around the inside corners of the film holder.
Each Tripod Mount is mounted to the Body with 3mm socket head bolts (16mm long), holding a 1/4 inch T-nuts captive. Glue on mating surfaces is optional. Tolerances are tight; I used a 1/8 inch drill to dress all 3mm holes and an extra T-nut as a disk sander to smooth the recess for the T-nut. The T-nuts I used have an 8mm shaft diameter - an 8mm drill bit makes these fit perfectly.
I have added an alternate tripod mount that takes a flanged 1/4 - 20 nut, if the T-nuts are hard to source. I will add pix to illustrate soon.
The Pinhole/Shutter assembly is clamped to the Extension with 4 - 3mm nuts and bolts, 16mm long. A dab of superglue can hold a corner of your pinhole in centered position during assembly.
--- LINKS ---
An encyclopedic article with cross references:
A self-described comprehensive pinhole tutorial:
The basics from Kodak - a quick and dirty primer.
Make your own pinhole:
Pinhole Designer - an excellent pinhole design and exposure calulator. The reciprocity failure function is gold. Sadly, Windows only, but worth it.
Mr. Pinhole - More calculators and more links.
Worldwide Pinhole Photography Day:
A paper pinhole camera, 2D printed in a Czechoslovakian magazine, in the 1970's: http://www.pinhole.cz/en/pinholecameras/dirkon_01.html
Books, books, books; Knowledge is power: