1 hour technical challenge

1 Hour Technical Challenge Q5. How does a pinhole camera work?

The simplest version of a camera is a pin hole camera. A pin hole camera requires a light-proof box, film of some sort and a pinhole. The pinhole is a tiny hole which is made using the tip of a pin and pushed into a piece of aluminum foil.

A pinhole can is a simple construction and there are a number of ways that it can be constructed using a number of materials.

The cameras can be all kinds of shapes and sizes, with various formats and types of light-sensitive material, several holes, curved film planes, for panoramic images etc. There are all sorts of imaginative ways to make these cameras. Ordinary objects can create pinhole cameras such as: a travel bag, a delivery van, an old fridge or even a hotel room.

A pinhole camera is very simple to use.

When the shutter is opened, the light shines through to imprint an image on photographic paper or film placed at the back of the camera.

Pinhole cameras rely on the fact that light travels in straight lines. This makes the image appear upside down in the camera.

You may end up with a black vignette around the image if you have a shorter focal length. And this may be exactly what you want.

The pinhole in a pinhole camera acts as the lens. The pinhole forces every point emitting light in the scene to form a small point on the film, so the image is crisp. The reason a normal camera uses a lens rather than a pinhole is because the lens creates a much larger hole through which light can make it onto the film, meaning the film can be exposed faster.

A small pinhole generally produces sharper images than a larger one. However, if the pinhole is too small, light waves may be scattered slightly at the edges of the pinhole and cause distortion or loss of focus.

The focal length of your pinhole camera is the distance between the pinhole at the front of the camera and the paper or film at the back of the camera.