F-Mount Pinhole Lens

This is a simple pinhole lens designed to fit any Nikon F-mount camera. The focal length of the lens is equivalent to about 67mm, and it has an aperture of f/256 (which equates to a viewing angle of about 30 degrees). A viewfinder is included, which slots into the hot-shoe of the camera, for easier picture composition. 

Print and Assembly Instructions

1. Print one each of the lens, retaining ring, and viewfinder. The lens should be printed with supports around the three thin flanges where it connects to the camera. The recommended print settings are 0.10mm layer height, 3 wall perimeters, and 20% rectilinear infill. This should take about 2.5 hours, and use about 30 grams of filament.

2. Cut the pinhole plate from an aluminium soda can. The plate should be square, with an edge length of 18mm.

3. Place the pinhole plate into the square cutout of the interior of the lens. The retaining ring can then be placed over the top of the pinhole plate to hold in in place. This is a friction fit, so a small amount of force is needed here. The retaining ring has a chamfer on one side to make it easier to push into the lens. Some superglue around the edge of the pinhole plate (where it meets the inner ring of the retaining ring) will help prevent any movement of the plate. If the ring is loose, superglue can be used to ensure it doesn't fall out.

4. The inside of the lens should now be painted black with spray paint. This is optional, but will result in less artifacts in the image.

5. Drill the hole in the lens plate using a wire-gauge drill (twist drill) with a diameter of 0.3mm. These types of small drill bits can be found on Amazon. Alternatively, use a small sewing needle to puncture a hole in the plate. This will result in a hole diameter of about 0.5mm, which will produce a wider image, although not as sharp. 

Usage Instructions

1. A marking is present on the lens to allow for easier alignment and mounting to the camera. Once the lens and viewfinder are mounted, the camera is ready to shoot. A tripod is required for this lens, due to the long exposure times.

2. The camera should be set to the "B" mode (bulb) for a manually timed exposure, and a trigger release is recommended.

3. For exposure on 100 iso film, use an exposure time of about 4 seconds in daylight, 30 seconds on an overcast day, and 30 minutes for a home interior. These exposure times can be reduced by using a higher iso film, or a higher iso setting on a digital camera.