Most novice and beginning photographers, when they buy their first digital camera, have no idea what a pixel is. Your curiosity is justified because camera manufacturers classify digital cameras based on megapixels. To understand megapixels, it is first important to understand what a pixel is. Technically, it is the single point in a graphic image. It can be reproduced at any size with no visible dots or squares. The word pixel means “(PI)ture (El)ement, with the common abbreviation PIX for IMAGE”. With a numerical value between 0 and 255, each pixel is made up of channels of three colors.
A digital image that has more pixels is considered higher quality compared to an image of the same size but with fewer pixels. Image quality is further improved when more pixels are compressed into each square centimeter of space. However, higher megapixel counts may not always translate to better images. In cheaper digital cameras with a large number of megapixels, the sensor may not be large or the pixel size may be smaller. This can reduce the quality of images.
The computer screen is a good example of what a megapixel looks like. The standard size of a computer screen today is 1024 by 768 pixels. This means that the number of pixels in this area is 786,432 pixels (1024 pixels multiplied by 768 pixels). This is pretty close to a million pixels. If you notice, the resolution of this screen is better than that of a computer, which can be 800 by 600 pixels.
The term megapixel refers to one million pixels. This means that a 1 megapixel camera, also sold as a 1 MP camera, can capture an image with a million pixels. In today’s photography world, such a camera is meant for beginners. Professionals use high-end cameras whose number of megapixels ranges from 14 MP to 22 MP. The megapixel count is also used to decide the size of a print. A 3MP camera can deliver excellent 4×6-inch prints, while a 4 or 5MP digital camera can deliver high-quality 8×10-inch prints. This is because the resolution of a print is directly proportional to the number of pixels. Another interesting metric is the pixel aspect ratio. You will find that camera manufacturers talk about a ratio of 1:3. This means that for every 1 pixel down, there is 1.3 pixels wide. This relationship is to give an idea of the dimensions of the photograph.
In addition to the number of megapixels, you may want to compare the image quality, optics, menu system, storage capacity, and responsiveness of different models before deciding on the effectiveness of a digital camera. Just looking at a pixel count doesn’t answer all the questions that need to be answered about the new camera.