Before I start I need to warn you that there is a risk of cutting your fingers and hands if you follow the assembly instructions. I accept NO RESPONSIBILITY for any such injuries. You do this at your own risk.
I recommend:
That you wear gloves when filing and cutting
That you read and follow all instructions regarding chemicals, their use, and their disposal.
That if you are under 18 you get an adult to help and supervise you
You will need:
An empty beer can
A can opener
Black gaffer tape
Black card
Sandpaper
A wooden spoon
A dressmaker's pin
AND . . .
A darkroom. This can be a loo, or an attic or shed or something similar. You will need to kit it out with three developing trays, and a safelight.
You will also need the following chemicals:
developer, stop bath, fixer.
For this activity you do not need an enlarger.
You may have to look around for these things try looking at the Patterson website or googling darkroom supplies in your area. You should be able to get these things for around £50 to £70
You will also need a computer loaded with something like photoshop plus a scanner and a printer
You will see from this list that you have to be dedicated to and focused to achieve an end result. NOT for the feint hearted
1) Overview of pinhole camera made from a beer can
This is a simplistic diagram of a beer can. I have drunk the diagrammatic beer (it was lovely) and I have cut off the top with one of those tin-openers that slices neatly around the tin without leaving jagged edges. It's VERY important to use one of these because a jagged edge will cut your fingers and let light in. Don't forget to wear gloves!
I have made a light proof cap out of black card and gaffer tape, I've made a small pinhole in the front of the can, and I have put a piece of black and white photographic paper inside the can.
I'll explain it all in detail as we go on.
2) Preparing the can
I use a can opener like the Culinare MagiCan
Wearing suitable gloves carefully take off the top of the can, and sand the resulting sharp edge down.
Take a 0.3mm (ideally) dress maker's pin and push it through the can in a central position. Make sure you remember where the hole was made as it can be quite hard to find later. I often put it through a memorable part of the can design.
Pushing the pin through the can will make the hole have a indentation or burr around the hole. This needs to be filed away. I use a bit of sandpaper wrapped around a wooden spoon handle to do this.
3) Making the light proof cap.
Get some black card which is thick enough to exclude light completely and using the picture below as a guide make a light proof cap that fits snugly but not too tightly over the top of the can. Use black gaffer tape to hold it all together.
Get a piece of tape about 2 inches long, and fold one end of it over on itself t create a little non-sticky bit. Stick this over the hole. This is your shutter. To open the shutter you will pull it away to let light in. To close it you will stick it back in place.
4) Loading the camera and taking a picture
Get some 5 X 7 inch black and white photographic paper from somewhere like Jessops
Under a "safe light" (it's a red light which will not effect the paper), or in complete darkness slip the paper into the can with the emulsion side facing towards the hole. This is actually quite a tricky operation. Look again at the General View. Remember that the top of the can is sharp and you are in danger of catching yourself in the fork between your fingers. so wear gloves please. Be patient; I know it is difficult.
Put the light proof cap on and make your way out into the world to find a place to take your picture.
When taking the picture it is essential that the camera stays dead still. You will need to put it down on a surface and possibly weight it with a shoe or brick or something similar.
Exposure: With every pinhole picture there is (in my experience) an element of guess work and luck as to how long to open the shutter. You can download from the internet a pinhole calculator; there are lots. Take a look at this page http://www.mrpinhole.com/
This will help you work out the shutter speed. I find that in normal daylight it ranges between 3 and 10 seconds depending on the amount of light available. Bear in mind that the image will be distorted because the piece of paper will be curved inside the can.
You will have to steady the top of the can with one hand before you remove the tape shutter. If you don't it will spin about and result in a blurred or misframed picture.
Put the shutter back in place and retreat to your darkroom.
This is a grab from a pinhole calculator. You put in the specifications of your camera and it will work out the exposure table. The figures shown will not work for your beer can camera. They are for some other camera that I made. The ASA for the paper will be about 2 or 3 I think. Whatever you will have to experiment a few times to work what works best for your camera.
5) Processing
In your darkroom make sure that there is no daylight coming in and that your safelight is on. Mix the chemicals as directed by their instructions.
Open the camera and take the paper out and plonk it face up and firmly and completely into the developer so that the whole piece of paper is covered at the same time.
Watch carefully as (with luck) a moment of magic happens. You should see an image start to appear on the paper.
If, when taking the picture, you have opened the shutter for too short a time (under exposed) it will take ages to develop, or (even worse) show no image at all :-(
If you have opened it for too long (over exposed it) it will happen very fast and go completely black if you don't stop it quickly.
To stop the process of development put the paper in the stop bath. This will stop the chemical reaction from happening.
Finally you need to put the paper into the fixer to stop the paper reacting to light ever again.
The times involves in these three processes will be indicated in the leaflet that comes with the paper, but to be honest I do it mostly by eye as the whole process is very volatile and hap-hazzard.
Finally the fixed image needs to be washed in a sink of cold water for a few minutes.
6) Scan and Print
When you look at the image you will notice that it is a negative in form. The dark parts of the scene will be white on the paper and the bright parts dark.
Place the dried paper into a scanner and using something like photoshop acquire the image from the scanner.
Invert the image. In Photoshop this is done in the image menu + Invert (on my computer the short cut is apple+i)
The image will become a positive image with the bright parts of the scene bright and the dark parts dark. Brilliant!
You can now adjust the brightness and contrast using the computer.
When you are happy print it out!
7) examples of pinholes from my own explorations:
Venice using a cardboard box and a hole made by Clare's brooch pin
Building works in Nottingham. This is made with a flat box
type pinhole camera. (I call it the "backless box)
Basford Tram stop, Nottingham. Backless box)
Basford, Nottingham. Backless box
Victoria Centre, Nottingham. Backless Box.