Megapixel (or megapixel) definition

Basically, a megapixel is equal to 1 million pixels. Sometimes it is abbreviated mpixel or MP, it is also used as megapixel.

The megapixel is often used to count the number of pixels in a digital image or also to measure the resolution of digital cameras.

For example, a 3.1 megapixel digital camera can take images with a maximum resolution of 2048 x 1536 (3,145,728 pixels).

Another example, the resolution 640 480 is 307200 pixels, which is equivalent to 0.3 megapixel.

Image quality of a digital camera and megapixels

The more pixels there are, the higher the resolution of the image, and the more times you can enlarge it without ruining the image quality through pixelation or pixel stretching.

Photos with more megapixels are larger in file size and therefore may take longer to transfer or send, and take up more storage space.

Most cameras and camera phones have the option to take photos at a lower (smaller) resolution, if desired. This can be useful to save storage space.

Megapixels are considered one of the most important features of a camera, but this measurement is not the only important factor that determines image quality. Megapixels only determine the size of the resulting image based on the total number of pixels. What really determines the quality of the images captured by a camera is the type and quality of the image sensor. The sensor makes the difference between a good 10-megapixel image and a bad one.

Recommended print size based on megapixels

The number of megapixels determines the size of the image that can be printed without loss of quality. For example, a 1.3 megapixel cell phone camera can take images that are good for prints up to 4×3 inches. If the image is enlarged beyond that size, the image quality degrades drastically.

As you can see from the chart above, almost any modern photography device now provides us with enough megapixels in the digital images it captures to make a good size print.

Using megapixels to achieve digital zoom or to crop images

A high number of megapixels is what matters most when enlarging or cropping a photo. For example, some phones allow users to zoom in without losing quality, without the need for an optical zoom lens. To do this, they simply crop an 8-megapixel photo from the center of the original 23-megapixel image captured by the camera (for example).

For more information read: digital zoom.

There are other reasons why you might want to buy a camera with more megapixels. Sometimes you want a part of a digital image you photographed that you find more attractive than the rest. If you crop the image slightly, it looks much better than it would if you left it alone. This is the main advantage of having a camera with more megapixels. It gives you a little more room to play when you’re cropping your photos.

Megapixels in digital cameras

A megapixel (MP) is one million pixels; the term is used not only for the number of pixels in an image, but also to express the number of image sensor elements in digital cameras or the number of display elements in digital screens. For example, a camera that creates an image of 20481536 pixels (3,145,728 finished image pixels) typically uses a few extra rows and columns of sensor elements and is often said to have «3.2 megapixels» or «3.4 megapixels». megapixels», depending on whether the reported number is the «effective» or the «total» number of pixels.

Digital cameras use photosensitive electronic components, either charge-coupled device (CCD) or complementary metal-oxide-semiconductor (CMOS) image sensors, which consist of a large number of individual sensor elements, each of which records a measured intensity level. In most digital cameras, the sensor array is covered with a patterned color filter mosaic that has red, green, and blue regions in the Bayer filter array, so that each sensor element can record the intensity of the light. a single primary color of light. The camera interpolates color information from neighboring sensor elements, through a process called demosaicing, to create the final image. These sensor elements are often called «pixels», even though they only record 1 channel (red, green or blue only) of the final color image. Therefore, two of the three color channels for each sensor must be interpolated, and a so-called N-megapixel camera that produces an N-megapixel image provides only a third of the information that an image of the same size would get from a scanner. Thus, certain color contrasts may appear more diffuse than others, depending on the primary color assignment (green has twice as many elements as red or blue in the Bayer array).

DxO Labs invented MegaPixel Perceptual (P-MPix) to measure the sharpness a camera produces when paired with a particular lens – as opposed to the MP a manufacturer sets for a camera product that relies solely on the camera’s sensor. . The new P-MPix is ​​intended to be a more accurate and relevant value for photographers when weighing camera sharpness. For example, in mid-2013, the Sigma 35mm f/1.4 DG HSM lens mounted on a Nikon D800 had the highest measured P-MPix at the time. However, at 23 MP, it still blotted out more than a third of the D800’s 36.3 MP sensor].

A new method of adding megapixels has been introduced in a Micro Four Thirds system camera that only uses a 16MP sensor, but can produce 64MP RAW (40MP JPEG) by taking two exposures, shifting the sensor half a pixel between them. Using a tripod to take multiple level shots within one instance, the multiple 16MP images are generated into a unified 64MP image.

related terminology

image resolution

pixel

digital camera

Digital image