Weekend Project #1 - Building a Pinhole Camera

December 31, 2007

Building a Pinhole Camera - By Kenneth Fagan
In our first “Weekend Projects” segment, we explore a fun and easy project brought to us by Ken Fagan, one of our moderators on the PhotographyBB Forums. Ken has put together some step by step instructions on how to build your own functioning pinhole camera, and has even included sample photos of his own pinhole camera! Let’s have a look:

A pinhole camera is basically just a light tight box with a tiny pinhole at the front and a film plain on its opposite end. They can be made from pretty much anything and contain absolutely no glass lenses or any of the materials which you would normally expect to find with a standard camera. In this article I will explain to you how to go about making one, preferably at absolute minimal expense, because I believe that pinhole cameras are meant to be cheap and use “on hand” materials.

To start you will need the following tools and materials:

- Cutting knife

- Sharp scissors

- Ruler (metal rulers are ideal but not vital)

- Set square (useful if you have one)

- Sticky tape / Sellotape

- Ducting tape

- Black matte paint (and paintbrush) or black tape (I used black PVC electrical tape)

- Cardboard at a workable thickness for main structure (about 2mm thick)

- Thin card stock (black) for front of camera.

Step 1

To begin, lay some card out flat and draw out a template, start by drawing a rectangle 140mm X 225mm. Draw a straight line down the centre of the rectangle on the length, where the centre line meets the top of the rectangle mark off 50mm on each side then draw a line from these two points down to the corners at the opposite end, so now instead of a rectangle you will have a shape 100mm wide at the top and 140mm at the bottom with a length of 140mm.

You will need 4 of these side panels to be cut (2 of Side Panel A, and 2 of Side Panel B). Each side of the templates must have a tab which allows each one to be joined together. Two pieces must have tabs on all four sides (Side Panel A), and two pieces must only have tabs on the top and the bottom (Side Panel B).

Once you have all these cut out they can be painted matte black on one side (the black side will be the inside of the camera) and tape them all together (the tabs give extra strength and make sure they are taped down or glued securely for a light tight seal) tape on both the inside and the outside, the result will be a four sided conical structure. The loose tabs on the larger end should be taped together to create a lip - this is essential for a light tight camera. Here’s what it should start to look like:

Step 2

Step 2 is the making of the front of the camera (with the pinhole). Start by laying out a piece of black card (not corrugated would be beneficial) and draw a square the same dimensions as the narrow end of the cone you made earlier by tracing the outline of it carefully onto the card (this helps if the measurements are a bit off) straighten and tidy up the lines using a ruler.

The best way of explaining how to construct this piece is by a diagram (see below) as it may get confusing otherwise as it is very important that it is “light tight”.

Step3

Once you have taped up the piece you made in step two, it is time to fit it onto the cone, it should fit comfortably, and pushed as far in as possible, momentarily use sticky tape to stop it from moving around while you make sure it is evenly placed, and perpendicular to the rear of the cone. Once it is secure and properly placed, use some ducting tape or PVC tape to tape it up (don’t be afraid to go overboard with the tape) keep taping up until its light tight ( use a flashlight to test it for light leaks).

When everything is taped up, get a pencil and draw two intersecting lines from top left corner to bottom right and top right corner to bottom left corner, where these two lines intersect is the centre, get a pin or a needle and pierce it once through the centre. A hole about 0.5mm is fine for a camera of this focal length (225mm).

Step 4

Step 4 is a crucial part of this project. If it is done incorrectly you most definitely will get light leaks. It is basically like a lid which the film is placed inside. The design came from the way 4×5 film is packaged, a lid, a box and then an inner box, 3 parts altogether.

Making the rear ‘film holder’ requires two parts, an outer lid and a frame to hold the film like an inner lid, you will see shortly the purpose of the ‘lip’

On a piece of card, draw an outline of the rear of the cone, then tidy it up with a ruler as you did with the front piece. In the diagram below you will see the cutout pattern and the assembly. Tape up all the joins and make sure that it is light tight.

Step 5

This is the final part of the project: Measure the dimensions of the hole in the rear of the cone, and make up a box that will fit neatly into the square hole. The box ideally should be about 10mm to 15mm deep. Fix this little box into the centre of the outer box/lid you made in step 4. The film is placed in the small box. When the Lid is completed, the lip blocks any stray light which may have entered the outer lid from reaching the small box (which holds the film), now you have (or, at least, should have) a completely light tight box apart from the pinhole at the front.

Finishing Touches

You will need to make a cover for the pinhole at the front. Do this by cutting out a 30mm x 30mm square from a piece of card, then punch a hole out from the centre about 10mm x 10mm. Tape it onto the front of the camera make sure you have the hole (you just made) centered over the pinhole. Tape only the two sides and the bottom, not the top, cut another square piece from thick card, and slot it into the space you left open. It should be smooth to move up and down but not loose. Now you have a completely light tight box, when you want to expose your film for a picture, remove the slide (like a lens cap) from the desired time and then replace it once the exposure time is up.

You will want the camera to sit straight so prop it up with some card (or empty tape roll) taped to the bottom of it.

Here are some sample photos taken with the Pinhole Camera:

The first of each image is the actual negative, and the second represents the image inverted, rotated, and flipped (because when the light hits the film in the camera, the image is upside down and backwards). These were also developed at home, so please forgive the specks on the film!

Image 1: 10 Min Exposure Time