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.
   

A stripped down view of the Digital Camera

Lets start simple with the digital camera camera, which was a 'wow' accessory half a decade back, but an affordable necessity these days.
Probably the biggest change in the digital camera which has gone well with the common user is the cheap replacement of the 'camera roll' of a film camera which captures some 30 odd pictures in a film roll, by a small piece of plastic memory card which never seems to fill up and can store photos over and over again(Well, technically speaking, the memory card is not the equivalent replacement of the film roll, but i'll get to that later). Add to this a display where you can see what you've clicked immediately...tat tah da!..you have got a winning combination!
The layman physics of what happens in a Digital camera is that an image seen through the lens of the camera is 'captured' by a sensor and transferred to a memory storage device(card). As simple as that :-).

Associating a sensor to a camera might be new to many. This unacknowledged device is the place where the Mega Pixel(MP) of a camera is decided!..That's important, isn't it?!. You could imagine the sensor as the canvas of a painter. Just as a painter splashes it with colors, the colors of the world are splashed on the sensor which(colors/images) is then digitized and safely tucked away in the memory card. It is the sensor that is the replacement for the film roll.

The technology behind camera sensors is nothing short of ground breaking. If you dig deep, you'll find that camera sensors are either CCD(Charge Coupled Device) sensors or CMOS sensors with the later being the relatively newer technology. I'll sign off this section with the info that the inventors of CCD shared the Nobel Prize in Physics for the year 2009.

My tryst with Photography...

Welcome:
Disclaimer: This is a photography blog but this post has got nothing to do about photography. Jump directly to the second post if you are not interested in my history!...

"Hey, focus the subject with a half-click and then take the picture"..so i scream at friends who use my DSLR.."er..whats half-click" comes back the reply in a jiffy...Without much of a choice, i abandon the reframe command that i was about to scream next and switch from Aperture priority mode to auto and say "just see through the "eye piece" and press the damn button!!...."

If this talk is even slightly alien,congrats!!, you are at the right place and on track to capture your first "educated" photograph.

Something about me and cameras....

My inspiration for photography stemmed from the numerous(clearly an exaggeration) compliments on my "good photographic sense" that i received with my mom and dad's very first digital camera(Sony with 3x optical zoom and no image stabilisation). When i decided to get my own digital camera i decided to go for a high end zoom camera as i had a craze for "zoom more than 10x" cameras back then. The brand loyalty in me made me go for a Sony and the winner was a DSC-H7 camera with 15x optical zoom. Though i had a very good experience with that i soon got tired of the zoom factor. In all fairness i'd've produced a decent shot at full zoom probly twice or thrice during the entire year i had the camera with me. Soon i decided to upgrade and after weeks of research it was a Nikon D80 DSLR(Digital SLR) that won my heart for practical cum sensible reasons!..Don't ask what happened to the fancy "brand loyalty" here!...I now use my D80 with a 18-105mm lens and a 50mm prime lens and eagerly waiting(saving would be more appropriate) to get some good lenses :-)

This is probably my 6th or 7th attempt at writing. Never mind what happened the previous times! This effort is to blog about basic photography stuff ,photographic terminologies and share some tips and tricks that i use. The inspiration , or to be more precise the nagging force behind this effort is my favorite model and good friend Sneha Mittal..:-)

Now that i have rambled on enough about me, lets shift the focus to clicking.....
And tabilder is from the Swedish terms 'ta bilder' which means 'take pictures'. Couldn't rake up any English name of interest, and hence this seemingly interesting name(pls don't dis illusion me here!)
Note : This is no way for advanced amateurs or professionals!...