Sensors and pixels for the beginner

A sensor known as a CCD, CMOS , or something else as new types are invented all the time.

The sensor is the part of a digital camera that captures light , turns it into a photograph and sends the image to be saved on a memory card. There are many types of sensor, as I've written, there are different types of sensor but as is a lesson beginner I will leave it at that, particularly as they all do the same job, although in a slightly different way and quality.

The sensor is covered with an array of light sensitive diodes that convert the information into picture elements that are known as pixels , to most people we jump a step and call the diodes pixels, again there are different shapes of pixels but lets keep things simple as most are square. When we talk about 10 million pixels or 10 megapixels, it means that the diodes will create 10 million small dots that will be of varying colors, these make up the image to be saved on the card. By this time the image has been automatically corrected and compressed by the camera with preset settings, these are known as jpeg images, on some cameras, there is a setting to override this in camera processing, and create a RAW uncompressed image, that allows the photographer to choose his own settings, allowing processing later on with a computer, this will be handled more in an advanced lesson.

So sensors are the part that captures the light and pixels are the small dots, that hold the information of an image.

Although generally we think the more pixels in an image ,the better the image quality, this is not true, as the size and quality of the sensor comes into play.

A word of warning never clean a sensor yourself, unless you have been instructed on how to do it, as damage can occur.

Lesson by:
Phillip McCordall