What is shutter speed in digital photography?

Shutter speed is the amount of time that a shutter is opened. Shutter speed is measured in term of second. Example of shutter speed value are 1/30, 1/15, 1/8, 1/4, 1", 2.5", etc. For shutter speed that involved a fraction, a higher denominator indicates a high shutter speed and vice versa. For a shutter speed that involved a whole number, it means a slow shutter speed. For example, 1" means 1 seconds.

Most point and shoot cameras have electronic shutter instead of the mechanical one found on the DSLR. Electronic shutters act in a similar way by switching on the light sensitive photo diodes of the sensor for as long as is required by the shutter speed. A disadvantage of using electronic shutter is that it will have a shutter lag. To combat shutter lag, it is good to pre-focus a certain object by half pressing the shutter button and when you are about to take the picture, depress fully to take the shot.

To start off with how shutter speed is used in photography, take note of the following points:

A shutter speed of 1/30 will probably be enough in most cases: This is because anything lower than that amount will result in camera shake. This will lead to image blur which is not desirable. If you found that the shutter speed is lower than that amount, you can try increasing the ISO value so that you can increase the shutter speed. Some cameras come with a built in image stabiliser to combat handshake. They are especially useful when you are taking an object in dim light environment. Alternatively, you can use a tripod to prevent camera shake.

A moving object: You can choose either to set a high shutter speed to freeze an object or choose a slower shutter speed to create a deliberate blur to the image. Whether you want to freeze an object or blurring the object will very much depend on the choisce of shutter speed used.

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Choosing the right shutter speed for long focal length: A good rule to remember when dealing with focal length and shutter speed is to choose a shutter speed at 1/focal length. This is because at high focal length, camera shake is inevitable so a high shutter speed is neccessart to combat handshake. Thus, if you are shooting at 200mm, a suitable shutter speed will be more than 1/200 to ensure the image is blur-free.

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