A camera, whether a simple point or shoot or a high end professional DSLR, pretty much works the same way that a human eye does. In fact, the entire electrical or mechanical functions of a camera are just a reflection of the biological function of human eye.
1. Cornea: transparent tissue covering the front of the eye. This is the part of the eye that lights travel through. Lens of a camera has the same function, let allow light to travel through to the sensor.
2. Pupil: Pupil is an opening in the center of the iris that changes size by narrowing or widening to control how much light is entering the eye. Iris on the other hand is a ring of muscles that helps pupil to narrow or widen. This is pretty much the same function that an aperture has in DSLR. You chose your FSET to decide how much light you would like to enter the sensor.
3. Eyelids: Your eyelids do the same function of that of a shutter. Shutter opens, light passes to the sensor. In other words camera is able to see. Shutter closes down, camera isn’t seeing anymore.
4. Retina: Retina is a membrane at the back of the eye that changes light into nerve signals. This is where the camera sensor comes into play. It gathers the light that travelled through the sensor and records it in form of electric signals, or in other words, forms the image.
It is however for a fact that even the most expensive camera in the world today is no-where closer to working with the same efficiency of human eye. It is said that to make a subject look the same way in a picture as our eyes saw it, a camera would have to be equipped with at least 600 megapixels. Imagine that!!!!!
