One of the main aspects of photography is composition of the subject. This includes various variables such as visibility, sharpness or softness, motion blur and other things and also includes lighting, exposure, ISO metering and other lighting related variables. For a top rated picture, the lighting must make it easy for the object to be identified and softly add a touch of importance to the area being focused upon. In digital photography these tenets are no different, but perhaps the advantage lies in changing these values dynamically and adding them without much of sweat for a beautiful photograph in the hands of the user within moments of assessment of the subject, or the object.
The most important part of a camera’s working is the aperture. Very simply, this is the diameter of the ‘hole’ that lets light into the camera’s sensor when the shutter is clicked. The size of the aperture determines the amount of light that is let into the camera. Larger the size, brighter the image. Apertures are measured by f-numbers such as f/2.8, f/5.6 etc. Smaller the f-number, larger the opening and thus more light streams into the camera. Each step of the f-numbers exactly double the intensity of light that streams into the camera. Aperture also has an important role to play with depth of field, i.e. the sharpness of the object being focused in relation to its background.
Exposure is the time the shutter is open for light to enter into. For a lot of people, this has no relation to the aperture – but it has. Each aperture increment or decrement in standard steps doubles or halves the amount of light entering into it respectively. So, if the aperture is increased and the exposure is decreased, the amount of light entering the picture is exactly the same, but the depth of field is altered, thus allowing for a differently focused photograph to come out of the digital camera. These settings can be dynamically changed using menus and buttons on basic point and click cameras as well!
ISO numbers are standardised indications of how sensitive the film of the camera is. Though the term “film” is obsolete in this age, ISO’s are still used to alter the sensitivity settings of the sensor. Lower the ISO number, lower the light sensitivity, but the noise levels are drastically reduced, while higher the ISO number, greater the light sensitivity, but at the cost of high noise.
