Saturday, April 01, 2006
Sensitivity and Sharpness in Digital camera
Sensitivity
You know that there are specific ISO settings in film cameras corresponding to different slow and fast speed of films or sensitivity of films. Slow speed films are used for bright light conditions and fast films for
conditions of low level lighting. You may also know that provision for automatic change of ISO setting on recognizing the sensitivity of the film loaded is also available in many cameras.
In digital cameras the sensitivity of the CCD is automatically adjusted. If you increase the sensitivity the images captured are likely to be overridden by noise.
The CCD sensitivity setting may range from ISO25to ISO 1600.Manual setting is also normally provided.
The need for manual setting may arise in low-level light conditions. Use of tripod is essential in such cases.
The working range of flash is normally reckoned with standard output sensitivity of ISO 200. Increasing ISO range also increases the working range of flash.
In case of a close up of, say a flower moving along the wind breeze, if you have made the aperture small to ensure maximum depth of field, the resulting slow shutter speed may result in a blurred image. If you increase the ISO setting now, the aperture and shutter speed will increase and capturing the image in a moment of freeze becomes possible.
In most of the situations, it is always desirable to keep a standard lower sitting and auto option ‘on’ in the camera’s menu.
Certain broad guidelines for ISO setting are given below.
Auto ISO is ideal for most of the situations.
ISO 80 may be chosen in bright light conditions for close ups, portraits and landscapes. Detailed and fine image quality can be expected.
ISO 100 may give a little less of image quality.
ISO 200 may be chosen for cloudy days. Image quality will be good.
ISO 400 and above will be the choice for in door photography and sports photography. High noise levels are to be expected.
Sharpness
The sharpness setting helps you to shift from a normal position to a sharp or soft setting when you want to have sharper outlines with increased contrast on the edges of the image or softer outlines. The sharp setting may be chosen in the case of edge of a building against the sky. The soft setting, which softens the edges, is chosen to create an ideal soft focus effect in portraits.
A normal setting is generally desired.
Saturation
A saturation setting is intended to add vibrancy to all colors. A normal setting keeps up balanced saturation with natural looking colors. Setting enables an increase or decrease in saturation.
