Lesson 1: Understanding Exposure:Part 1/4

'Exposure'  is a simple word that every hand holding a camera should be aware of...Its a magic term that makes you feel like Sachin with a cricket bat or Federer with a tennis racket!...But before we start digging to substantiate this seemingly preposterous claim of mine, we need to know two small components of a camera which together form the basis for exposure.

I'll build this section from a line that i used in the earlier post. '..an image seen through the lens of the camera is 'captured' by a sensor and transferred to a memory storage device'.

Lets just take up '..an image seen through the lens is captured' by a sensor.' - Well, that is the honeymoon view of things...Its slightly more complicated than that in reality!...The lens is an optical device which sticks out of the camera when you switch your digital camera on. This lets all the light to enter the camera. The light has the image in it. So far,so simple...

 Now comes the two components that decide on how much light that enters the lens should fall on the sensor. They are,

1. Aperture
2. Shutter

I'll connect the significance of the "how much" of the previous line with 'exposure' later in this post or in the next post.
   Aperture is an opening or a hole of variable size that places the first breaks on the light that enters the lens. Think of it as a 8 lane road suddenly becoming either a 2 or a 4  lane road. The second and final break is applied by the shutter which decides on how much time the light let in by the Aperture has to fall on the sensor by opening and closing for that amount of time. Simple ain't it? !Well, that's exposure for you!..When you take a picture in Auto mode, the camera decides for you how on how big the aperture has to be and how long the shutter has to open for that particular picture. This combination for deciding on how much light has to fall on the sensor is called as an Exposure. Exposure means what it means literally!..

    Now that we know the basis of exposure, we are all set for some interesting posts on exposure. I'll post in the following fashion.

1. Explain more about Aperture and how you can use this knowledge in deciding on your next purchase of a digital camera. For example you'll learn to appreciate difference in an 'Aperture Range : Auto(F3.5-F10) / Program Auto(F3.5-F10)' specification of a 250$ Sony T90 Cyber-shot Digital camera  and an 'Aperture Range : Auto(F2.5 / F5.1(W), 2 steps) / Program Auto(F2.5 / F5.1(W), 2 steps) ' specification of a 100$ Sony DSC-W180 Cyber-shot camera.
2. How Aperture and Shutter speed are related. And the need to restrict the amount of light falling on a sensor and thereby the significance of  exposure. i mean why not let the full light fall on the sensor and save all these gory details!..
   
3. Understand Underexposture and Overexposture and how you can add creativity to your photographs by varying aperture and shutter speed.