Foundation
Early Photography
Camera Obscura
In the 9th century the Arabian scientist, Alzahen, invented the Camera Obscura to capture still images in a dark room through a small hole with a convex lense or aperture. The image would appear inverted vertically, the artist would then use the projected image as a stencil to draw or paint over. The Camera Obscura would become recognised as the first camera and the first step towards a fully digitalised camera of today.
Many artists in the 17th century were very fascinated in creating a realistic image. Capturing a photograph documents reality in an instant, using light and time to reproduce a moment, as it is seen in real life. |
Johann Heinrich Schultz (left), a professor of anatomy, after experimenting discovered that silver salts, especially a piece of chalk dipped in silver nitrate turned black from white when exposed to the sun. The unexposed side kept its original colour.
In 1834, an English scientist, Henry Fox Talbot (right), created the Calotype process. This is when paper is soaked in silver chloride and fixed with a salt solution. Talbot created positive images by contact printing onto another sheet of paper. |
Louis Daguerre was a French painter and physicist who invented the first practical process of photography, known as the Daguerreotype. It used a silver plate which was polished and coated with silver iodide and "developed" with warmed mercury. The Daguerreotype could only make positive images so copies had to be made by taking another photo. He won the battle for the most popular type of photography over Henry Fox Talbot, mostly because the government made it freely available to the public.
This is the model of Camera Obscura that I made. It's made from cardboard and lens. When light comes through the lens onto the tracing paper it appears vertically inverted.
Shutter Speed
1"
1/125
1/500
Shutter speed is the length of time that the shutter within your camera is open, and this affects the amount of light let into the camera sensor. If the shutter speed is slow, light is let into the camera for longer. You can use a slow shutter speed to capture movement in an image, or if you're taking an image in a darker area. If the shutter speed is fast then it lets light into the camera for a shorter amount of time. Fast shutter speeds are used to capture a freeze frame in an image, and shows a still image of movement.
Aperture
Aperture refers to the opening of a lens's diaphragm through which light passes. It is calibrated in f/stops and is generally written as numbers such as 1.4, 2, 2.8, 4, 5.6, 8, 11 and 16. The lower f/stops give more exposure because they represent the larger apertures, while the higher f/stops give less exposure because they represent smaller apertures.
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F4.0 F8.5 F11