When we talk about the Galaxy S5, LG G3 or iPhone 5s,you may hear us rambling on about IPS this, AMOLED that, Retina whoduzzit and new fangled LCD thingamabobs and scratch your head and wonder what the heck we're talking about. Well, today we're going to clean that confusion right up for you as we break down how each display type works, what they're good at and which is best for you. And don't worry, we won't go too heavy on the geek speak.
Note: The moiré effect visible in some photos is related to the mode of shooting, not the display type.
LCD means Liquid Crystal Display. As you can probably figure out, LCD is made up of an array of liquid crystals that get illuminated by a back light. Because LCDs don't require much energy to power a screen, the technology is very popular in portable devices. Likewise, because LCDs are back lit, they tend to perform quite well in direct sunlight, as the entire display is being illuminated, so they are ideal for smartphones. However, this back lighting means that blacks tend to appear gray and they therefore have less contrast than some other display technologies. There are two main types of LCD: TFT and IPS.
TFT stands for Thin Film Transistor and they are an advanced version of LCD that uses an active matrix (like the AM in AMOLED). Active matrix means that each pixel is attached to a transistor and capacitor individually. Their main advantage is their relatively low production cost and increased contrast when compared to traditional LCDs. Their disadvantage is more excessive energy consumption than some other LCDs, and less impressive viewing angles and color reproduction.
IPS stands for In-Plane Switching and it is an improvement of TFT LCDs. To summarize very roughly, the way the crystals are electrically excited is different and the orientation of the crystals array is rotated. This change improves viewing angles, contrast ratio and color reproduction. Energy consumption is also reduced compared to TFT LCDs. Because IPS LCDs tend to be better than TFT LCDs, they are also more expensive when put on a smartphone.
To identify whether a smartphone has an IPS or TFT screen, just look at the technical specs: if they simply say it is an LCD then you know it's a TFT LCD; IPS LCDs are always labeled as such.
A Retina display is not defined by any particular characteristic, other than that they are supposedly of sufficient resolution that the human eye can't discern pixels at a normal viewing distance. This measurement obviously changes depending on the size and resolution of the display. Apple popularized the concept with the iPhone 4, which had a 960 x 640 pixel resolution on a 3.5-inch IPS LCD screen, resulting in 330 pixels per inch. Considering the current 5.5-inch QHD displays sit at 534 ppi you can see that in the Android world we've moved on a bit from the iPhone 4.
Apple, on the other hand, have stayed true to Steve Jobs' dictum and the current iPhone 5, 5c and 5s all have a Retina display with 1136 x 640 pixel resolution for a pixel density of 326 pixels per inch. With a rumored large-screen iPhone 6 coming up, we'll have to see just what resolution Apple opts for in a device that will have to go head to head with the best Android displays available. With a 577 ppi Galaxy S5 LTE-A being released in China, a 300 ppi iPhone 6 would be a prime target for criticism.
AMOLED stands for Active Matrix Organic Light-Emitting Diode. While this may sound complicated it actually isn't. We already encountered the active matrix in TFT LCD technology, and OLED is simply a term for another thin-film display technology: OLED is an organic material that, like the name implies, emits light when a current is passed through them.
As opposed to LCD panels which are back lit, OLED displays are ''always off'' unless the individual pixels are electrified. This means that OLED displays have much purer blacks and consume less energy when black or darker colors are displayed on screen. Because the black pixels are off, the contrast ratios are also higher than LCD screens. AMOLED displays have a very fast refresh rate too, but on the down side are not as visible in direct sunlight as back lit LCDs. Screen burn-in and diode degradation (because they are organic) are other factors to consider.
Difference between AMOLED and Super AMOLED
Super AMOLED is the brand name given by Samsung to its range of displays that, like IPS LCDs, improve upon the basic AMOLED recipe. Super AMOLED displays reduce the thickness of the screen by integrating the touch response layer with the display itself. Super AMOLED displays handle sunlight better than AMOLED displays and are also better on power consumption. As the name implies, Super AMOLED is simply a better version of AMOLED.
OK, got it: so which one is better?
As we have seen, each term is not restricted to one manufacturer: AMOLED is not always Samsung and Retina is not all Apple. iPhone IPS LCD displays are currently manufactured by LG, Samsung has built screens for the iPad and not all Samsung devices are AMOLED either. As is probably clear from our explanations above, it is not simply a case of which display is better: it's all a trade off between pros and cons.
All of this is to say two things: numbers and technical data are obviously important when comparing the screens on two smartphones, but equally important is the real-world performance of these displays. It is impossible to gauge a display on paper, you really need to see it in real life to know if it is too cool or warm for you, is too saturated or has too poor contrast, brightness, viewing angles and so on. Don't fall into the trap of believing the marketing hype. Analyze the displays for yourself, ask other users on the forum, or if a device is not yet available, then seek the advice of sites whose opinion you trust.
Lastly, know your usage habits and select accordingly: if you are a couch potato all night and are desk-bound all day, then the daylight viewing benefits of LCDs are probably not so important for you, but if you're an outdoors type then maybe they are. If you're crazy about squeezing every drop of life out of your battery or are simply obsessed with eye-popping color, then take a look at AMOLED, and so on. In some ways the grass will always be greener, but you can still make informed choices that tick as many boxes as possible for you.
What kind of display do you prefer? Tell us why it's your pick in the comments!