Simple Explanations of Smartphone Specifications (Part 2)

This article is divided into three parts:

PART 1: Networking technology | SIM technology | Body specs | Hardware | Memory & Storage

PART 2: Display type | Touchscreen | Resolution | Pixel density | Aspect ratio | HDR | Refresh rate

PART 3: Camera | Sound | Comms | Sensors | Battery

In Part 1, we looked at networking technology, SIM cards, body specs, hardware, memory and storage. Part 2 will look at all the specifications relating to the display.

5. Display

Display specs of the Samsung Galaxy S20 Ultra 5G (left) and the Apple iPhone 12 Pro Max (right).

Display type

The two main types of displays in smartphones are LCD and OLED. Both of them have their own sub-types, each with their advantages and disadvantages.

LCD

The Liquid Crystal Display (LCD) uses backlit liquid crystals to display images on a screen. The crystals themselves do not produce any light, so the backlight is a very important part of an LCD.

LCD screens are perhaps the most commonly used in smartphones, especially in budget and mid-range smartphones. TFT LCDs are the cheapest type of LCD and are most commonly found in entry-level smartphones. The problem is TFT displays have a narrow viewing angle and don’t perform well in direct sunlight.

The best type of smartphone LCD on the market is the IPS LCD. You won’t struggle with it in direct sunlight and it also provides you with a wider viewing angle than you’d get from a TFT LCD. For this reason, IPS displays are more expensive and commonly found in mid-range devices and higher.

OLED

LED display panels have light-emitting diodes (hence the name LED) that produce light themselves without the need for any backlighting. This makes them more energy-efficient than LCDs. In the world of smartphones, LED displays are more commonly referred to as OLED, which stands for organic light-emitting diode.

There most popular name in smartphone OLED display is Active Matrix Organic Light-Emitting Diode, a.k.a. AMOLED. This type of display provides excellent colour reproduction, high contrast, and longer battery life.

Super AMOLED is Samsung’s OLED technology which improves on the quality of AMOLED displays. Super AMOLED handles direct sunlight much better than AMOLED and uses up even less power. And because the touch sensors are built into the display itself, this makes the Super AMOLED display the thinnest on the market.

Samsung has also introduced Dynamic AMOLED, which is said to be very similar to Super AMOLED but with HDR10+ certification.

Retina display

Retina Display is a marketing term coined by Apple for its brand of displays. It basically means that the display has a high pixel density, which makes it difficult for the eye to see individual pixels on the screen. The technology behind Retina Displays is IPS LCD although OLED is also used.

Touchscreen

There are two types of touchscreens found on smartphones. Resistive touchscreen and capacitive touchscreen.

Resistive touchscreen

Resistive touchscreens work by sensing the pressure applied on the screen by the user. When the screen of the phone is touched, two thin layers of the display are pressed together creating an electrical connection that can be sensed and located.

Resistive touch screens work well with a finger or a stylus.

Capacitive touchscreen

Capacitive touchscreens do not rely on any sort of pressure applied on the screen. Instead, this type of touchscreen uses electric charges to sense where the screen has been touched. And because the human body carries an electric charge, capacitive touchscreens appear more sensitive and responsive to the human touch.

Unfortunately, unless it is made of conductive material, a capacitive touchscreen will not respond to a stylus.

Haptic Touch

Haptic Touch is a feature that was introduced in Apple smartphones starting with the iPhone XR. If a phone has Haptic Touch, it pretty much means it recognises a “touch-and-hold” gesture (or long-press/touch) instead of just a simple touch.

Haptic Touch-enabled smartphone gives you to access different options depending on the touch. In other words, a simple, quick tap on a phone’s display can perform certain tasks, while a tap and hold gesture (Haptic Touch) can give you other options.

3D Touch

Just like with Haptic Touch, 3D Touch can give you different options depending on how you touch the same spot on a smartphone’s touchscreen display. You can gently tap on a 3D Touch display to use the phone as you normally would.

But unlike Haptic Touch, 3D Touch works on the pressure applied to the display, not prolonged contact, to access other options. In other words, if you tap and hold on a 3D Touch smartphone, it won’t do anything. What you need to do with 3D Touch is press down harder on the display to get other options.

Colour depth

Colour depth basically refers to the number of colours a smartphone’s display is able to produce. The human eye is believed to be able to see 10 million colours. So, if a smartphone is said to have 16M colours (16 million), then it can produce colours well beyond what we can discern. That’s known as True Colour.

These days, it’s not unheard of to see smartphones with 1B (1 billion) colour depth. It’s commonly referred to as Deep Colour.

Resolution

Resolution is a term that encompasses multiple aspects of a smartphone display such as the physical size of the display, the number of pixels it has, and how many pixels there are per inch (ppi).

Simply put, the resolution of a smartphone display gives you an indication of how much detail and information the screen can display. Generally speaking, when it comes to the resolution, the higher the numbers, the better the display.

Below is a table that shows you the most common smartphone display resolutions, and how many pixels they each have.

Pixel density

Pixel density is a calculation that shows you how many actual pixels there are within the space of an inch on a smartphone’s display. Pixel density is expressed as pixels per inch or ppi. The higher the pixel density, the better the viewing experience will be.

The human eye can see a maximum of 300ppi from a distance of about 76cm (2.5ft). If a smartphone has a pixel density that is higher than that, it simply means that even when held closely, the display will not look pixelated (provided the displayed image is of good quality), and the human eye will not be able to see the individual pixels.

However, the bigger the screen, the higher the pixel density should be for the best possible display quality. A small HD display with a high pixel density (e.g., 400ppi) will look better than a large QHD display with a lower pixel density of only 256ppi.

Aspect ratio

A smartphone display’s aspect ratio refers to the relationship between the height and the width of a display. It is most often written as a ratio, with the first number on the left usually referring to the width and the second number referring to the height.

For example, an aspect ratio of 1:1 is a square because the width and the height are the same. An aspect ratio of 16:9 (the most common aspect ratio) is a rectangular display because the width (16) is greater than the height (9).

Sometimes, the aspect ratio is presented as a decimal. The first figure of the aspect ratio is divided by the second figure to get a decimal aspect ratio. For example, a display with a 16:9 aspect ratio can also be said to have a 1.78 aspect ratio (16÷9=1.78).

HDR

HDR stands for high dynamic range. It refers to the high contrast between the dark and the light areas of an image. In terms of smartphones, an HDR display means that the screen will make bright areas of an image appear as bright as they should be without losing any detail while keeping dark areas as dark as they should be without losing any detail there either.

The two most common forms of mobile HDR are Dolby Vision. Based on how it works, it may seem that Dolby Vision performs better than HDR10. However, more and more smartphones are adopting HDR10+, which is an improvement on HDR10 that puts it on par with Dolby Vision.

Screen refresh rate

Similar to how video cameras create moving images, smartphone displays (and any other digital screens, for that matter) create the illusion of motion on the screen by displaying multiple images per second consecutively on the screen.

The number of times in a second that the display changes is known as the screen refresh rate, which is measured in hertz (Hz). The higher the refresh rate, the less motion blur will be visible when scrolling at high speeds. This makes for a smoother user experience, especially when dealing with fast-moving images.

The standard screen refresh rate for smartphones is 60Hz, which means the display changes 60 times in a second. Some smartphones have screen refresh rates as high as 90Hz and 120Hz. The latter is a popular option for smartphone gaming, although the game has to be designed to take advantage of the high refresh rate for it to make any difference.

Screen brightness

The brightness of a smartphone display is expressed in nits, a unit of measurement that describes how bright a display is. The higher the number of nits, the brighter the display.

A smartphone with a screen brightness of around 400 nits is pretty much average. The further below that you fall, the more likely you are to struggle when using the device out in the open sun. Some smartphones have a peak brightness of over 1000 nits.

Screen-to-body ratio

Presented as a percentage, the screen-to-body ratio is basically a measure of how much space the display takes up on the phone. The larger the percentage, the more of the phone’s front face is covered by the display.

Always-on display

The Always-on display is a feature on some smartphones that allows the screen to display certain information such as date, time, notifications, etc. even while the phone is asleep. This feature also goes by other names such as Active Display or Ambient Display on some phones.