The technology behind digital cameras

Photography is no longer unpredictable and, for better or for worse, the ‘snap and hope for the best’ feeling that once accompanied every photographer is now far behind us. Film stock was not cheap and the disappointment of realising that 15 out of 20 of our holiday snapshots were shaky, overexposed, or even burnt, was enough to put most of us off that hobby forever.

Thanks to digital cameras, photography today has exploded. Using dslr technology we can preview and erase any pictures we don’t like. We can take pictures with our digital cameras, our phones, our ipods, our laptops, and even underwater, with our waterproof cameras, such as the canon powershot, millions of pictures are uploaded daily on facebook and other social networks, making photography one of the most common routines of our daily lives.

However, has anyone ever stopped and wondered what exactly happens when we take a picture? With old-fashioned cameras, the process was tangible and therefore easy enough to understand. The lens created a small replica of the scene inside the camera by focusing the light. This light then shined on the film, imprinting the image. This image was eventually exposed with the help of chemicals in the laboratory.

What happens with digital cameras though?

Digitals use what is known as nanotechnology. When you take a picture with a digital camera, light falls on a series of digital sensors instead of a strip of film. These digital sensors are called chips and they are made up of millions of sensory elements, the pixels, which is actually short for ‘picture elements’. These are laid out in lines and columns just like in an excel spreadsheet.

So, when you read something such as 3008x2000 pixels it means that you have 3008 across and 2000 down. If you multiply these two numbers, the result you will get will indicate the sensor elements of your camera in millions e.g. 3008x2000= 6,016,000 = 6megapixels. Each contains a little piece of your image.

The more the megapixels, the larger the digital analysis of your camera. The digital analysis is commonly known as resolution. This is why you are generally advised to buy a camera with as many megapixels as possible, as when you come to print your photos the quantity of megapixels will make all the difference.

Today you have extremely sophisticated cameras, like the Canon Powershot camera, which will provide you with 12.1 megapixels of resolution or over, as well as having extra features like being waterproof, freezeproof and shockproof.

But how do megapixels work exactly? First of all the image goes through the colour filters, and then though the image sensors. Each sensor translates this image into a light wave, which is then transformed into an analogue-electrical signal.

This then goes through a digital converter where it becomes an actual analogue signal. Any pixels that are left over get discarded thus the image we get in the end is the compressed version of the original.

This compressed and filtered image gets stored into the digital camera’s buffer memory and then on an external device such as a memory card. And then you take it from there, either printing the photos or transferring them to a hard drive, thus freeing your memory card for its next lot of savored moments.