Foundation Portfolio In Media Amber Wilkinson: Aperture, Shutter speed and ISO

f-stop(aperture)-an adjustable opening which controls the amount of light coming through. The lower the number, the shallower the depth of field. This will mean it will be wider and you will have a brighter image. It is a camera setting corresponding to a particular f-number, measured in f-stops. A high f-stop like f-22 means that the aperture hole is quite small, and a low f-stop like f/3.5 means that the aperture is wide open. If you shoot with the aperture wide open, then more light is allowed into the camera than if the aperture is closed down to only allow a tiny hole of light to enter the camera.

source: http://digital-photography-school.com/aperture/

Graphic explanation of the aperture for photography basics learners

Graphic explanation of the aperture for photography basics learners

Aperture/f-stop scale

shutter speed- how long the shutter is open for and therefore the longer the shutter is open, the brighter the image will be. Has an interval of 25, measured in seconds. The bigger the denominator the faster the speed (ie 1/1000 is much faster than 1/30). Most of the time, 1/60th of a second or faster is used otherwise a tripod is needed to reduce blur and still create clear images even with a slow shutter speed.The amount of time that the shutter allows light onto the image sensor is called the shutter speed, and it is measured in fractions of a second. A shutter speed of 1/2 a second would allow more light in, giving it a brighter image.

Graphic explaining the effects of changing the shutter speed

Shutter speed scale

film speed -its sensitivity to light. Film speed is the measure of a photographicfilm's sensitivity to light, determined by sensitometry (Sensitometry is the scientific study of light-sensitive materials, especially photographic film) and measured on various numerical scales, the most recent being the ISO system. A closely related ISO system is used to measure the sensitivity of digital imaging systems.

ISO- ISO stands for International Organisation for Standisation. The higher the ISO the more sensitive it is. Each ISO setting is double the one before: if you increase the ISO from 100 to 200, you double the camera’s sensitivity; and if you increase it from 200 to 400, you double it again. This carries on through the ISO scale. You tend to set the ISO first on a camera.