ISO

The ISO is an important aspect of digital photography and will allow you to have much more control over your photography.

 
Changing the ISO setting on your camera is one the the quickest ways to see results in your photography. Learn what the ISO does and how to use it and I'm sure you will be surprised.
 

What is the ISO?

 
ISO was traditionally the measure used in film photography to determine how sensitive the film is to light. The ISO is measured in numbers, 100, 200, 400 800 ect ect. The lower the number the less the film is sensitive to light.
 
ISO now is used in digital photography for setting the image sensor's sensitivity to light. Depending on the modal of camera you have the range of ISO will differ ranging from 64(slow ISO) to 1600(fast ISO). 100, 200, 400 and 800 are the most popular ISO settings and one that you will use the most.
 

Photographic 'noise' and ISO.

 
Photographic noise is when a photograph becomes grainy, this is usually a result of using a high ISO.
 
When the available light is low a higher ISO is used to allow a shorted shutter speed. This is helpful when photographing action or sport shots indoors. The problem with using a high ISO will probably result in a grainy or noise photograph. When used in full auto mode the camera will set the ISO and try and keep it as low as possible to avoid those noise photographs. All most all cameras give you the option to set the ISO yourself and to gain more interesting and crisp photographs.
 

How to set the right ISO.

 
 
Before setting the ISO you need to think about a few things,
 
  • How much light there is. How well your subject or scene is lit.
  • Is the subject still? Is there a lot of movement in the scene or is it going to be totally still.
  • Will you be holding the camera? Are you using a tripod.
 

How much light is there?

 
Here is a simple chart to help you get the right ISO for the light conditions.
 
ISO Speed
Light conditions
100/200
Bright sunshine
400/800
Over cast skies or sun set and sun rise.
1600
Night and dark indoors.
 
So basically the more light the lower the ISO. The more the available light the less sensitive the light sensor in the camera needs to be.
 

Is the subject still?

 
If your using the camera mode that sets the shutter speed and aperture but allows you to set the ISO then by increasing the ISO your camera will set a faster shutter speed.
 
  • Low light moving object that you want to capture as a still image = set a high ISO which will give you a faster shutter speed.

 

Will you be holding the camera?

 
If your shooting in low light and the subject is moving you will want to make sure your camera is held still by using a tripod or resting the camera on something stationary.
 

ISO over 100.

 
ISO 100 is considered as normal. ISO 100 is the ideal ISO as the images will be crisp, but it is not possible to use ISO 100 in some situations.
 
Here are some situations where you may want to increase the ISO;
  • Indoor parties: where the light is low and you want to capture candle light or a atmospheric photograph.
  • 'No flash zones': These may include art galleries, theaters and concert halls, museums, Churches, ect.
  • Indoor sports events: The subjects are moving fast and there is limited lighting.
 
Things to remember when setting the ISO;
 
  • By increasing the ISO the camera will set a faster shutter speed to gain the correct exposure, this will allow you to capture moving object.
  • By increasing the ISO the amount of noise in the photograph will also increase.
  • Use the lowest ISO that you can for the available light.
  • Don't be afraid to play with the ISO on your digital camera, you wont have to worry about waisting film after all!
 
Abby x

 

 

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