Whether when buying smartphones, cameras or monitors – the information on the pixel display is always equated with the image quality. But what is a pixel actually about? What is described by pixels and megapixels? And what size are the pixels? Find out below.
- A pixel is an image point in a raster graphic.
- Several subpixels result in one pixel.
- The size of a pixel depends on the resolution of an image.
What is a pixel
The term pixel stands for the image point in a raster graphic. In English this point is called “Picture Cell” – abbreviated: Pixel. Each image shown is made up of millions of pixels. In practice, the word pixel refers to the individual pixels on a panel, for example on a television or your home theater – or on a smartphone display. The finer the pixel grid, the higher the resolution of the display or screen. A standard full HD monitor has around 1920 x 1080 individual pixels. These are arranged in a grid.
How is a pixel constructed?
A pixel consists of several sub-pixels. These dots in green, red and blue come together as a whole to form a pixel in any color tone and thus create the overall picture in interaction with other pixels.
How does a pixel affect image quality?
With larger screens, each individual pixel is correspondingly larger. The dimensions and the distance between the individual points affect the sharpness and clarity of the respective image. If you look at a screen from a short distance, you can sometimes even see the fine subpixels. If a pixel is defective, it either always lights up or not at all. In the latter case that means: it remains black. These pixel errors then stand out from the overall picture and may even affect the viewing experience.
Adjust the pixel size on the display
In order to get an optimal picture, it is sometimes advisable to change the pixel size. This can easily be done in the settings for many displays and monitors. You vary the resolution and in this way adjust the size of each individual pixel. For example, reduce the resolution from 1920 x 1080 to 1080 x 720 in order to reduce the number of pixels – with the same display size. The pixels become larger accordingly.
How big is a pixel?
Pixels are not of a fixed size. Rather, it depends on the resolution of the image. The following applies to printed photos: The resolution information is given in pixels per inch (ppi). One inch is 2.54 cm. This information tells you how many pixels can be found on one inch.
What are megapixels?
The term megapixel is mainly used in product descriptions for cameras and smartphones. A high number of megapixels stands for high image quality. Basically, it can be said that a megapixel comprises one million pixels. This defines the resolution of the image. With a higher resolution, a recording has more depth of detail. In the case of a camera or smartphone camera, however, various other factors also play a decisive role.
So have, among other things
- the focus,
- the brightness setting and
- the noise reduction
Influence on detailed photos.
The added value of the high resolutions
The added value of oversized resolutions is rather low. The modern full HD displays with 1920 x 1080 pixels, i.e. 2.5 megapixels, can only reproduce the exact details precisely when you zoom in.
When printing photos, however, you should always use a high number of pixels. This enables you to enlarge certain sections or to cut the desired areas without the notorious “stairs” being visible.
How to find the optimal resolution for your pictures
If you want to design your own website, the recommended resolution for photos is 72 ppi. When printing pictures, however, different guidelines apply to getting the best results. The distance of the viewer and the overall size must also be taken into account. Instead of the unit ppi, the unit dpi for “dots per inch” is used here. With a long viewing distance – for example on an advertising panel – around 30 to 40 dpi are recommended for motifs larger than 2000 x 2500 mm. For posters smaller than 800 x 1500 mm – at normal viewing distance – 100 to 150 dpi are advisable.