Pixels are the small dots that make up your computer, TV, and phone screen. Digital displays are comprised of pixels. Pixels work together by switching colors extremely fast to create a persistent and smooth viewing experience for the user. Learning everything there is to know about pixels is a challenge especially as screen technology changes more rapidly. But there are some basic terms relating to these tiny dots that make up so much of our world that are helpful to know. Let’s jump in!
Resolution is the total number pixels are on a given screen represented as dimensions of width and height. You may be familiar with the term 1080p when referring to a computer screen or TV. 1080p is a simpler way of saying 1920×1080 which is a pixel count of 1920 pixels wide and 1080 pixels tall. This is an extremely popular standard for widescreen computer screens, TVs, and (more recently) phone screens over the past few years. Videos have a resolution as well. Video cameras will shoot certain resolutions (most often 1080p these days) and screen recordings are based on the resolution of the recorded screen.
It takes a lot of computer power to run high resolution screens, which is why it takes a while for new resolution standards to be adopted into the main stream. 4K (easy term for a resolution of 3,840x 2,160) is four times as pixel dense as 1080p, thus a much sharper picture. As consumers adopt 4K screens, more 4k content is being produced. 4K video cameras are starting to become affordable, Netflix streams 4k content to subscribers with compatible devices, and video game consoles are starting to adopt the standard as well.
Most computer screens have pixels that only produce red, green, and blue. Every other color is created from a precise mixture of those three base colors. Pixel depth refers to the number of colors a particular pixel can produce. A higher color depth means more colors and a more realistic and well represented image. Color depth is represented in bits, each bit adds exponentially to the number of visible colors. The lowest possible color depth is 1 bit for a total of two colors, black and white. A standard computer usually supports 24 bit color (224) which is 256 shades of red, green, and blue respectively for a total of 16,777,216 possible colors each pixel can produce. So while a higher resolution will make your picture sharper, a higher color depth will make it more vivid.
Pixel density is the relationship between the number of pixels on a screen (resolution) and the physical size of the screen. Just like resolution this affects the sharpness of the digital image. The denser the pixels the sharper the image. A 24″ computer screen at 1080p is technically sharper than a large 60″ TV at the same resolution, though the difference can be negligible to the untrained eye. In recent years phone manufacturers have been in a pixel battle, rapidly increasing the resolution of their relatively tiny screens resulting in very pixel dense devices (for example 1080p on a 5″ screen.) The benefits of this are sharp video, browsing, and games. These dense screens are particularly useful as virtual reality applications become more common-place. These applications use the gyroscope in your phone to track your head movements, but for full immersion require a head mounted adapter which puts the phone very close to your eyes. VR at lower pixel density suffers from the immersion breaking screen door effect
Phone based VR in a not-so-recommended setting.
With these three terms under your belt (resolution, color depth, and density) you should have a basic understanding of pixels. But there’s much more to cover on each of these topics as well as many others we didn’t get to cover. For more on video resolution specifically check out our blog posts What is hi-res and Why is my video blurry.