Photography Evaluation

Pinhole Camera
As the name suggests a pinhole camera has an aperture the size of a pinhole. The only professional equipment that needs to be used when creating a basic pinhole camera is the photographic paper itself. The rest of the camera can be made from any light-tight box from anything such as a metal biscuit tin to a cardboard mobile phone box. The inside of the camera should be painted black to stop any unwanted light from bouncing around inside and creating undesired effects on the photographic paper.

The photographic paper needs to be held in place within the box, this can be achieved using some masking tape or Blu-Tac. The aperture must be directly opposite, and centred, to the photographic paper. Light is projected in a straight line so the cone of light that has entered the camera, through the aperture, has been inverted onto the photographic paper and is known as a ‘negative’.

It is important not to over expose the photographic paper. This is why a shutter is vital to the camera. The shutter can be made up from a simple piece of cardboard and tape that will cover the aperture at all times when you are not taking your picture.

The calculation we used to determine how long the shutter needed to be open for was;

Focal Length / Diameter of pinhole = f.stop

The focal length is the length from the aperture to the back of the tin/box (where the photographic paper is situated).

My pinhole/aperture was 0.8mm.
My focal length was 9mm.
f. stop = 118.75

Due to the large f.stop number of a pinhole camera, photos will encounter severe over exposure if the shutter is open for too long and result in a dark or completely black image.

Using a rough guide this equated to a 45 second open shutter or ‘shutter speed’ for outside locations and for 10-12 minutes inside. This proved to be too long and overexposed all of the images so we halved the exposure time, creating much better results.

Developing Film.

The developing of black and white photographic paper takes place over three steps.

Before you begin it is imperative that the camera is opened up in the dark room. Exposing the paper to any light will clearly ruin your picture.

The paper has a light-sensitive surface called the emulsion. In it there are silver halide grains; silver atoms bonded to chlorine, bromine or iodine atoms. If you expose a silver halide grain to light, the photons in the light will loosen the bond between the silver and the halogen. The paper is usually suspended in gelatin.

1. Developer.
The developer is a chemical that makes the latent image visible. It does this by reducing the silver halides that have been exposed to light to elemental silver in the gelatine matrix.

2. Fixer.
Typically a dilute solution of acetic acid or citric acid. This halts the developing of the picture.

3. Water.
Washes off any remaining chemicals.

Below are the original negatives I shot and also the Photoshop edited images (on the right).

Atrium
4 minute 30 second exposure.

I darkened this shot slightly so the blacks and whites are more distinct and prominent.














Outside Bike
0 minute 20 second exposure.

This shot could have benefited from a further five seconds of exposure. The sharp edges of the buildings and pavement goes well with the bike leaning against the railing.

Outside Trees
0 minute 20 second exposure.

This exposure captured the detail of the gravel and concrete bench extremely well.












Mug Shot
3 minute 0 second exposure.

This shot didn't come out too badly considering I had to lean against the window looking like an idiot for three minutes. The background didnt come out at all because there simply wasn't enough light in the room. The slightly blurred effect is because I am not a robot.