Understanding ISO

At times it can be impossible to achieve the desired aperture or shutter speed to take a photograph. This usually occurs in low light situations where you need to use a large aperture, but, because it's getting dark, you have no other choice than to use a slow shutter speed. This shutter speed required may well be too long to hand hold the camera without causing camera shake and fuzzy pictures.

In these situations this is where the sensitivity of your camera sensor comes into play by controlling ISO. Even though digital cameras do not use film, the industry has retained the expression ISO (International Standards Organisation). ISO refers to the light sensitivity of a camera's image sensor. Lower numbers like ISO 100 are less light sensitive and produce better quality images because 'digital noise' is kept to a minimum. Higher numbers such as 1600 ISO, whilst more sensitive to light, can suffer from increased digital noise.

Digital cameras allow you to adjust the image sensor's sensitivity by dialing in different ISO settings. This can be done between shots and for this reason a digital camera can rapidly adapt to changing light conditions.

The practical use of ISO is this:

• If you use a low ISO setting you need more light in your photograph, which is controlled by your aperture, shutter speed or both.

• A low ISO setting results in better quality.

• If you use a higher ISO setting you will not need as much light in your photograph but you do riskadegredation in quality caused by'digital noise'.

Cameras have an ISO range from 100 to 1600 and several pro camera models go up to 6400 and higher! In a perfect world it's best to shoot at the lowest ISO, such as 100 or 200, but this is not always possible.

Digital Cameras For Beginners

Digital Cameras For Beginners

Although we usually tend to think of the digital camera as the best thing since sliced bread, there are both pros and cons with its use. Nothing is available on the market that does not have both a good and a bad side, but the key is to weigh the good against the bad in order to come up with the best of both worlds.

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