How to Understand Pixels

What are pixels? How important are they. This article explains pixels, camera size, and how to decide what to buy.

Difficulty: Easy

Instructions

1. What is a pixel?
   A pixel is a light capturing device, which in large groups on a sensor (often a CCD or CMOS sensor: the abbreviation for the types of sensors. CCD=Charged Coupled Device, or CMOS=Complementary Metal Oxide Semiconductor. I only add this to define the letters, it's more than most folks need to know, but I hate it when letters etc. are not defined!) Many new cameras use the CMOS sensors because they now use less electricity.
   Interestingly, pixels are not a color, there is a filter above each pixel which is only red, green or blue which determines the color captured by the pixel.

2. Pixels are arranged on the sensor as tiny squares (on most common brands), just like a checkerboard. The count of pixels is determined like acreage or length by width and rounded off to the nearest number, like 8Mp.
   The sensor in your camera, which is generally not much bigger than a large postage stamp, takes the place of film, and captures light information, which is then translated into zeros and ones which are stored on the memory card in your camera. When re-translated by most programs and computers these files can be turned into a photo.

3. The number of pixels on a camera has been increasing every year. The term mega pixel is the common designation for the number of pixels on a sensor. Mega being the prefix for a million, if you have an eight mega pixel camera, there are eight million pixels on the sensor, which, remember, is not much larger than the average postage stamp! The common belief is that the more pixels you have, the higher the quality the enlargement can be made. Also, the more pixels you have, you can still make a reasonably nice quality image from only a cropped part of the image.

Tips & Warnings

• The common cameras on the market these days are reaching large mega pixel counts. Eight to twelve mega pixels are quite common on small cameras (the point-and-shoot style), and eight or more is common on the DSLR (Digital Single Lense Reflex cameras - those which have interchangeable lenses.)
• The number of pixels is therefore, not even important these days as most folks rarely make prints, and even more rarely a print larger than 8x10. All cameras on the market these days will easily make very nice 8x10 prints at the cameras highest quality settings.
• The drawback to cameras making large size images (High mega pixel count), is that they also make large files, and many email programs will not accept more than one or two large files (if that many), for attachment to an email. Preventing sending of the email.
• Image size must then be reduced to send as an email attachment. Many programs are available to reduce file size, and NIKON cameras as well as some other brands have added this reduction option to its menus to perform this function on images on the memory card while in the camera.
• If you are not planning to make large prints, a smaller mega pixel camera (6 mp) will serve your needs quite well.