Camera And The Eye

The eyes as we know is that part of the body which helps us see. The phenomenon of the working of the eye is very similar to that of a camera. The human visual is system (HVS) is as complicated as the working of a camera.
Whatever we see, is the result of the message sent through the eyes to the brain. The brain interprets the signals sent from eyes to it hence allowing us to see what is in front of us. To understand a camera, human eyes should be understood first. It would be really fascinating to know the similarities and dissimilarities of both the processes.

Our eyes have ISO (sensitivity), like that of a camera, with the help of which we are able to adjust to various intensities of light. In bright light, our eyes’ ISO falls and we are able to see fine details of objects and can easily see all bright colors. Whereas in dim light, ISO of our eyes becomes higher, which makes us able to see in the dark.
Our eyes, very quickly adapt to the bright light, but in comparison, take a longer time to get adjusted to a dark environment. This is the reason we can’t see anything when we enter a dark-room while when we move out of it, it takes very less time to adjust to the bright sun-shine. Though our irises may hurt a little in this process of adaptation to the bright light.
But in case of a camera, a photographer has to do the task. The fuzziness of the view has to be removed by adjusting and modifying the light. This is automatically done by retina in case of human eye.

SHUTTER SPEED

Vision is a continuous process of the human eye. But eye-lids act as shutters which creates a small time gap between two continuous visions. This small time gap is the shutter speed which is adjustable in case of camera but natural in case of human eye. According to researchers, an eye on an average has a shutter speed of around 1/50 of a second. Whereas, shutter-speed of a camera can vary from as less as 1/4000 of a second to as high as 2 seconds. Some cameras may even have an exposure time (shutter speed) of a few hours according to the need of the photographer.

APERTURE

Aperture of the eye or the lens decides the depth of field that is the area which remains in focus. The size of the hole of the aperture allows the required amount of light entering in the eye or the camera which results the focusing of a particular object of the whole view. The aperture of our eye is the black spot in the centre of the eye. It can vary from 1mm in the brightest light to 9mm at the night time. This is why this black spot shrinks when we move out in bright sun-shine and expands when we enter a dark-room.