photography breakdown

ISO:

In a camera there is a light sensitive sensor which can tell how much light falls onto the sensor and in what parts to produce an image. The way ISO works is to control the sensitivity of the sensor, the higher the ISO the more light sensitive the sensor is. One way to use this in photography is to counter wether your in dark conditions or very bright conditions, for example if you are taking pictures in a very low lighted room, you can raise the ISO so your picture turns out well. Depending on what sort of camera you have the range of ISO can vary, the very high end cameras have the whole range.

This images shows the way ISO can influence an image

Aperture:

aperture allows you to change the depth of field in the photo, by this i mean it influences the focal length and sharpness in different regions of the image. The way it works is in the lens, the lens has shutter blades to allow certain amount of light into the camera but creating a hole, by changing the aperture you can change the size of the hole. The bigger the hole is the more light is let through into the camera, as a result the focal region is smaller meaning the blurred areas are extremely blured. If the hole is smaller there is less light going into the camera which in turn makes more of the image sharper.

The unit of measurement for aperture is the 'F number', the higher the 'F number' the smaller the hole is. A lower 'F number' the larger the hole is. Some specialist cameras such as prime lenses have a aperture range which is a lot lower than normal lenses, This is for certain types of photography such as portraits.

The diagram below will illustrate the aperture setting and what the hole would look like.

This photo was shot which a very high aperture therefore more of the image is in focus. They best time to use a high aperture is in landscape and architectural photography where you want all parts of the image to be sharp.

This image was shot with a low aperture (f/5.0). More of the image is blurred so the attention is shifted towards the subject more. this is great for macros photos and especially in portraits.

Shutter speed:

shutter speed controls how long the light sensitive sensor is exposed to the light, This is done using a shutter which stays closed. when the shutter opens the picture is being taken, when the shutter closes the photo is finished taking the picture. using the shutter speed you can change how long the shutter stays up. If the shutter speed is fast the image will capture moving targets in a still shot and will reduce motion blur, the side effect of having a fast shutter speed is that you image will tend to be darker because less light is being registered.

A slow shutter speed with register more light because the sensor is exposed for longer, this can be used to take really good effects such as light streams, misty water and rolling clouds. The image will also be blurred if there are moving subjects but this depends on the length of the shutter speed.

In this image the shutter speed was fast enough to capture the water sprout whilst in mid air, this means that the shutter opened and closed before the water moved to much. Normally the image would be pretty dark but because its was outdoors and very bright it canceled out and created a good photo.

Here is an image i took with a very slow shutter speed. The light streams were done by vehicle lights being registered by the sensor and they go past. This is great for landscape photograph and cool city photos.