Most novices and beginner photographers, when purchasing their first digital camera, do not have the slightest idea what a pixel is. Their curiosity is justified because cameras makers today categorize digital cameras on the basis of megapixels. To understand megapixels it is first important to understand what is a pixel. Technically, it is the single point in a graphic image. It can be reproduced at any size without the appearance of visible dots or squares. The word pixel stands for “(PI)cture (El)ement, with the common abbreviation PIX for PICTURE". Having a numerical value between 0 and 255, each pixel is made of three-color channels.
A digital image that has more pixels is considered to be of a higher quality when compared to a picture of the same size but with less number of pixels. The quality of the picture becomes even better when there are more pixels compressed over every square inch of space. However, a higher megapixel count may not always translate into better images. In cheaper digital cameras with a high megapixel count, the sensor may not be large, or the size of the pixels may be smaller. This can reduce the quality of the pictures.
The computer screen is a good example of what a megapixel is like. A standard computer screen size today is 1024 by 768 pixels. This means the number of pixels in this area is 786,432 pixels (1024 pixels multiplied by 768 pixels). This is quite close to a million pixels. If you notice, the resolution of this screen is better than a computer screen, which can be an 800 by 600 pixel.
The term megapixel refers to a million pixels. This means that a 1 megapixel camera, also sold as 1MP camera, can shoot a picture with one million pixels. In today's photography world such a camera is meant for beginners. The professionals use high-end cameras whose megapixel count ranges from 14 MP to 22 MP. The megapixel count is also used to decide the size of a print. A 3MP camera can provide excellent 4x6 inch prints, while a 4 or 5MP digital camera can deliver high quality 8x10 inch prints. This is because the resolution of a print is directly proportional to the number of pixels. Another interesting metric is the pixel ratio. You will find the camera makers talk of a 1:3 ratio. This means that for every 1 one pixel down, there are 1.3 pixels across. This ratio is to give an idea of the dimensions of the photograph.
Apart from the megapixel count, you may want to compare the picture quality, optics, menu system, storage capacity, and responsiveness of different models before deciding a digital camera's efficacy. Just looking at a pixel count does not answer all the questions that need to be answered about the new camera.
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