What is pixel, megapixel and how many they are necessary for a good photo?
With emergence and a wide circulation of digital equipment in everyone there was an opportunity to expand the creative appetites. Now process of creation of photos is not so labor-consuming, as during a film era. And rather available or as they are called still, the budgetary models of digital cameras allow even to the beginning pictorialists to create quite decent works.
The pixel wide popularity received the term together with popularity of figure. The term is formed as reduction of the words picture element (“ image " element;) . It is about points that form the picture which we see on the computer display or the screen of the TV. One photo made by figure can consist of several million such points.
Any pixel consists of five elements of information. Two are responsible for its coordinates: situation on verticals and situation across. And three more define color: brightness red, brightness blue and brightness of green color. In common all these elements of information allow the reader to define the correct color of a point and to place it in the correct place on the screen. All pixels filling the screen together form one shot.
But the term megapixel is even more often used . It is size in one million pixels from which the image is created. Usually measure the size of the photo or the scanned picture in megapixels. But at the choice of the camera in megapixels one of its essential characteristics - permission of a matrix is displayed.
Of shop I was convinced that than more this indicator, will be better for those. But actually it turned out that the number of megapixels - not the most important indicator of quality of the device.
the physical size of a matrix - the it is important more, the more qualitative the picture will turn out. Even at the identical number of pixels quality of photos from different cameras can be a miscellaneous. The size of pixel cells gains paramount value in comparison with their quantity. The pixel size is less, the image noise level is higher.
If on a matrix with diagonal 1 / 2,5 inches to realize 8 and more megapixels, it will turn back continuous presence of noise even at low values of a photosensitivity. In compact cameras and the majority of reflex cameras undesirable effects are smoothed by the built-in program of noise reduction, but its intervention leads to a picture zamylennost.
Of course, the size and quality of the image depends on the number of megapixels. But whether you thought of why the majority of image banks establishes the minimum border in this parameter in the area from one to four megapixels? The matter is that it is even quite enough two megapixels to print a good picture of a format 10õ15, and 4 megapixels will be enough to create a qualitative photo 20õ30.
Besides, the size of pixel cells together with quality of photo diodes influence such indicator as dynamic range is an ability of photosensitive cells of a matrix to reproduce object details in the certain range of steps of an exposition. In other words, depends on this characteristic, the chamber how precisely can transfer shades.
But even if the matrix with high resolution is installed in the camera, the cheap optics can spoil a picture literally of this word. Properties of a lens often do not correspond to stuffing opportunities therefore compact tsifrovik are not suitable for serious shooting. Nearly 90 percent of amateur tsifrovik have matrixes on which from 5 to 12 million pixels are located. Reflex cameras resolution have from 8 to 21 million pixels, but the sizes of sensors much more.
Values of intensity of pixel differ on the geometrical and color accuracy, dynamic range, existence of noise. These characteristics are influenced by number of the photodetectors used for its definition, quality of a lens, combination of sensors, the sizes of photo diodes, the preset programs of processing of images, a format in which the image etc. of
However remains if you are not going to organize a photo exhibition and to be engaged in a photoart closely, it is quite possible to find adequate model for specific objectives. And for expeditious shooting, placement of a photo and sending on the Internet it is quite possible to choose an optimal variant - compact tsifrovik the average level. Experts recommend to pay attention to 5 - 8 - megapixel models , i.e. to choose for creative works of nonprofessional photographers golden mean - such permission quite enough to receive the accurate and colourful picture.