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(i) Aperture
An aperture is simply a small hole or opening into the camera, which allows light to get in. The size of the aperture and the brightness of the scene controls the amount of light that enters the camera during a period of time
The lens aperture consist of overlapping movable leaves which forms a diaphragm set to different ranges of diameters so that the quality of light admitted is controlled.
Apertures control the amount of light reaching the film. The size of the aperture can be controlled depending on the amount of light present i.e. large aperture used for dim light and small aperture used when there is bright light.
The aperture also can increase or reduce the depth of field i.e. Depth of field is simply the zone of sharp focus in front and behind the focused object .NB as the aperture is reduced, the depth of field increases.
The aperture is usually adjusted by turning a narrow ring near the focus control (in some cameras) these include intermediate setting, which creates progressive doubles and halves the light that is admitted.
Each setting is given an f-number. Some simple cameras use weather symbols instead of f-number
(ii) Shutter
A shutter is simply a knob at the top of the camera, which is normally pressed when taking an exposure.
The shutter controls the length of time that the light hits the recording surface Shutters not only control the exact moments when the film is exposed to light but also the duration of exposure i.e. the amount of light that is admitted .
The length of time the shutter remains open controls the quantity of light that reaches the film. Shutters are fitted within or just behind the lens body and use a set of blades, which rapidly opens or shuts. They sometimes consist of two separate blinds positioned just in front of the film.
Shutter speed (the speed in which the shutter opens and closes the aperture to allow light) varies but the longest time it should remain open is 1 sec and the shortest is 1/250 sec ,although for others its 1/500,or 1/1000sec.
Shutter speed affects or determines how moving objects record on the picture, high shutter speeds eliminates the effects of blur, it reveals details but reduces the sense of movement .to help reduce or avoid the effect of camera shake and blurs, the shutter speed should be high or alternatively the camera should be supported on a tripod stand
NB: shutter speed and the size of the aperture can be used constructively to control sharpness of the image, the depth of field and blur