Thursday 23 September 2010

Pinhole Camera


Scott Bourne


Pinhole photography is lensless photography. A tiny hole replaces the lens. Light passes through the hole; an image is formed in the camera.
By making a pinhole camera, you must insure that the inside of your desired object which you will be using to create the body of your pinhole must be painted completely black on the inside. The main reasons for this is because light travels in straight lines and the only colour that absorbs light is black. All other colours on the spectrum reflect the light which as a result could cause defects on your image that you will be producing.
Pinhole cameras are small or large, improvised or designed with great care. Cameras have been made of oatmeal boxes, coke cans or cookie containers. Cameras have been cast in plaster like a face mask, constructed from beautiful hardwoods, built of metal with bellows and a range of multiple pinholes. Station wagons have been used as pinhole cameras – and rooms in large buildings. Basically a pinhole camera is a box, with a tiny hole at one end and film or photographic paper at the other.
In serious photography the pinhole camera is just an imaging device with its advantages and limitations, special characteristics and potentials. By making the best of the camera's potential great images can be produced. Some of the images could not have been produced with a lens.
All cameras work in a way much like the human eye. The image if it were not corrected would be constantly upside down. The reason for this is because light travels in straight lines, and as you can see from this diagram the ray of light at the bottom hits the top of the box and visa versa for the top.

 


With a pinhole camera there must be a precise time on how long the cover must be left open for, this is known as the F stop. The way that we figure out the F stop is by finding out the width of your desired box. Once you know the width of your box you, divide it by 0.8 then this will give you somewhere between 90 and 93.
Apertures is a definition for the size of the diaphragm opening in a camera lens regulating the amount of light passing through onto the film inside the camera the moment when the shutter curtain in the camera opens during an exposure process







Making the can or box Pinhole
A pinhole camera is a small, light-tight can or box with a black interior and a tiny hole in the center of one end. By using common household materials, you can make a camera that will produce pictures.
Making the pinhole camera is quite an easy and simple process which requires little skill, the only down side is that it is time consuming. First to begin with its best to paint all over the inside of the box or can with black. This is because the only colour that absorbs light is black. All other colours reflect light. Once the pinhole is painted in black, cut a square hole in the box. This will be for the lens. Then play foil over the hole and stick it down with tape. Then make a cover to protect the photographic paper from being ruined.
The Box:
When you make a pinhole camera for roll or sheet film, use a small can or box as the camera body. You can use anything that has a tight-fitting top - a clean paint can, a vegetable shortening can, a 2-pound coffee can, a shoebox, or even a cylindrical oatmeal box.
To make the can light-tight, paint the inside with dull black paint or line it with black paper to prevent light reflections. If the can you use has a plastic lid, paint the lid black.
Be sure to paint it inside and out; then before using it, check to make sure no paint has chipped off. Chipped or peeling paint on the lid will allow light to enter the camera and ruin your pictures.

Pinhole camera
made from a can.


The Pinhole:
The film will be attached to the inside of the lid so you will need to make the pinhole in the bottom end of the can. You can make the actual pinhole in the can itself, but it's much easier to make it in a separate piece of heavy black paper or thin metal and fasten this piece over a larger hole cut in the center of the bottom end of the can. Heavy-duty aluminum foil is good for this purpose.

The distance of the film from the pinhole and the diameter of the pinhole will determine the angle of view and sharpness of your final image. For a camera with the pinhole 3 to 6 inches from the film, you'll get the best results if the pinhole is about 1/75 inch in diameter.

The Shutter:
The shutter for the camera can be a flap of opaque dark paper hinged with a piece of tape. Use a small piece of tape to hold the shutter closed before and after you take a picture.

Loading a Can or Box Pinhole Camera:
You can load the camera either with film or fast photographic paper. Your choice of film or paper may depend in part on the exposure times. Paper, because it is less sensitive to light than film.Paper is easier to handle since you can load it into the camera under a safelight. If you don't have a safelight, you can work by the light of a flashlight covered with several thicknesses of red cellophane paper placed 6 to 8 feet away. Most film, on the other hand, must be handled in total darkness.

Exposure:
To get clear, sharp pictures, your camera must remain very still while the shutter is open. Use plenty of tape or a lump of modeling clay to hold your camera still. Lift the black paper to uncover the pinhole and keep the pinhole uncovered for the recommended time. Cover the pinhole with the black paper between exposures.
The following table gives approximate exposure recommendations for a pinhole camera. It's a good idea to make three exposures of different durations for each scene to improve the likelihood you'll get a good picture.




 These were the two original pictures that i took with my pinhole camera. The one at the top is taken with the camera on the floor and it is of a corner part of the college building. It captures the stoned floor coming out of a dark colored building as-well as some of the college bushes.



This photo was again taken on the floor. It captures the old building of the college and also captures the new building. I positioned the camera so that it captures both. It gives off that feeling that because the old building is black its showing its old and unused whereas the new building is white and looks fresh, clean and nice to look at.






Evaluation:
In my evaluation i will be discussing what i could have possibly improved on with my pinhole photography work. Drawing near to the end of my photography work i was able to realize that the duration of the cover being left open was mere seconds. I think the longest amount of time i left the cover open for was 1 minute. The problem that i found with this was that by leaving the cover open to long, i was actually over exposing the photographic paper to the light. this meant that once it had gone through the developing stage most of the picture came out black. What i also found out was that there is a much shorter time on leaving the cover open if you are to take a picture outside rather than inside, this is because there is more direct sunlight hitting the box outside than if you were to take a picture inside.

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