Camera & Exposure

The amount of light being recorded by the camera when taking a photo is referred to as the exposure. This exposure is regulated by the shutter speed, aperture and ISO settings. Different setting are required for correct exposure in bright light compared to low light.

For your exploration of Exposure you will need to produce a series of images demonstrating your understanding and control of Shutter Speed and Aperture. Once you have produced these images and annotated them in your visual diary you will then need to produce 1 final image that applies your understanding of Exposure to create aesthetic qualities in a final image. This final image will need to be extensively annotated to explain how you have used materials and techniques to communicate ideas and create your aesthetic qualities.

Shutter Speed

Shutter Speed controls exposure by the amount of time the shutter is open. Longer times let more light in and shorter times let less light in.

Shutter Speed is measured in fractions of seconds or full seconds. A fast shutter speed will freeze motion and a slow shutter speed will blur motion.

1/250th and above is considered fast. Most cameras do not go above 1/8000th
1/125th to 1/60th is considered normal and the cut off before you need a tripod.
1/30th to 1/2 is considered slow
1 or more seconds is considered very slow. Normal cameras usually max out at 30 seconds
B stands for Bulb In Bulb the shutter stays open for as long as you hold the shutter button down.
Shooting in TV (time value) mode lets you control Shutter Speed while the camera selects aperture for you.

Aperture

Aperture, like shutter speed, controls exposure but is regulated by a series of plates inside the lens with a hole in the middle that can be made bigger or smaller.

Aperture is measured in strange numbers called f/stops as seen of the left.

The larger the Aperture hole the more light it lets in and the less the background is in focus
The smaller the Aperture hole the less light it lets in and the more the background is in focus.
The extent to which the background is in focus is called Depth of Field.
Shooting in AV mode lets you control Aperture while the camera controls Shutter Speed.

ISO

ISO is the the third exposure control and probably the least interesting.

ISO basically sets the sensitivity of the film or sensor and is rated in numbers that go; 100, 200, 400, 800 etc.

As you increase your ISO the camera becomes more sensitive, so can correctly exposure with less light.
But the down side is as you raise the ISO your images become more noisy or grainy.
Generally you want to keep your ISO as low as possible and only raise it as a last resort.
Early digital cameras were really bad a low ISO but more recently the technology has improved greatly and they can now easily produce good looking images at 1600 to 3200 ISO.

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