What do camera pixels mean?

Pixel is the basic unit of a digital image, and the resolution of the image is usually expressed in pixels per inch (PPI). So pixels refer to the resolution of the camera. The larger the pixel, the more photosensitive elements, and the greater the corresponding cost. The image quality of a camera is partly determined by pixels, and it is meaningless to compare it with pixels when it is larger than a certain size. At present, the pixel of mainstream SLR cameras is about1000000, but 5 million pixels is enough for ordinary photography and home use, because the resolution of the display we use is limited, generally from 1024×768 to 1920× 128.

In addition, besides pixels, there are two concepts that we have to know.

maximum pixels

The English name is Maximum Pixels, and the so-called maximum pixel is obtained by interpolation. Interpolation operation through the built-in DSP chip, when the image needs to be enlarged, the nearest neighbor interpolation, linear interpolation and other operation methods are used to add the pixels that need to be added after the image is enlarged. The image quality obtained after interpolation operation can't be compared with the real photosensitive image. Some merchants in the market will mark "XXX pixels can be realized by hardware interpolation", which is the same principle, but from the perspective of image quality and sensitivity, photos taken with the largest pixel are not as clear as those taken with effective pixels. The largest pixel also refers directly to the pixel of CCD/CMOS photosensitive device. In order to increase sales, some businesses only promote the maximum pixel. When setting the picture resolution, they do take pictures with the highest pixel resolution. However, users should be aware that this is the value obtained through internal calculation, and the loss of image quality will be very obvious when printing pictures.

effective pixels

Effective number of pixels is called effective number of pixels in English. Different from the largest pixel, the effective pixel number refers to the pixel value that really participates in photosensitive imaging. The value of the highest pixel is the real pixel of the photosensitive device, and this data usually includes the non-imaging part of the photosensitive device, while the effective pixel is the value converted under the zoom magnification of the lens. Take Minolta's DiMAGE7 as an example, its CCD pixel is 5.24 million (5.24 megapixels). Because some CCDs do not participate in imaging, the effective pixel is only 4.9 million. Digital pictures are generally stored in pixels, and each pixel is the smallest unit in digital pictures. The larger the pixel, the larger the area of the picture. To increase the area of a picture, if no more light enters the photosensitive device, the only way is to increase the area of pixels, which may affect the sharpness and clarity of the picture. Therefore, under the condition of constant pixel area, the camera can get the largest picture pixel, which is the effective pixel.