OLED vs LED LCD – An in-depth guide to the rival display technologies
It’s an understatement to say that 2018 has been a big year for screen tech. Ultra HD 4K continues to be adopted as the standard resolution in the TV world. High dynamic range (HDR) is no longer the next big thing – it’s already here. The same can be said of smartphone screens, which continue to reach dazzling levels of sharpness thanks to increased resolutions and better pixel-per-inch densities.
But for all the new features coming our way, it’s worth taking a minute to consider an old battle going on between two display types. Two display types that can be found across monitors, TVs, mobile phones, cameras and pretty much any other device sporting a screen.
In one corner is LED (light-emitting diode). It’s by far the most common type of display on the market, and it features in all kinds of tech. However, it might be unfamiliar to you because there’s slight labelling confusion with LCD (liquid crystal display). For display purposes, the two are the same. If you see a TV or smartphone that states it has an ‘LED’ screen, it’s actually an LCD. The LED part just refers to the lighting source, not the display itself.
The trouble is, it’s a completely different technology. Some people say OLED is the future, but is it really that much better than a good LCD display? Well, we’re here to find out. We reveal how the two display technologies differ, what they’re good for, and how they work.
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OLED vs LED LCD – How are they different?
In a nutshell, LED LCD screens use a backlight to illuminate their pixels, while OLED’s pixels actually produce their own light. You might hear OLED’s pixels called ‘emissive’, while LCD tech is ‘transmissive’.
The light of an OLED display can be controlled on a pixel-by-pixel basis. This sort of dexterity just isn’t possible with an LED LCD – but there are drawbacks, too, which we’ll come to below.
In cheaper TVs and LCD-screen phones, LED LCD displays tend to use ‘edge lighting’, where LEDs actually sit to the side of the display, not right behind it. The light from these LEDs is then fired through a matrix that feeds it through the red, green and blue pixels and into our eyes.
OLED vs LED LCD – Brightness
LED LCD screens are brighter than OLED. That’s a big deal in the TV world, but even more so for smartphones, which are often used outdoors, in bright sunlight.
Brightness is generally measured in ‘nits’ – roughly the light of a candle per square metre. The OLED-equipped iPhone X has a typical peak brightness of 625 nits, while the LCD-toting LG G7 claims a peak of 1000 nits. In the TV world it goes further – Samsung’s QLED TVs can go over 2000 nits.
Brightness is important when viewing content in ambient light or sunlight, but also for high dynamic range video. This applies more to TVs, but phones are increasingly boasting of video performance, and so it matters in that market too. The higher the level of brightness, the greater the visual impact, which is half the point of HDR.
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LG OLED TVs
OLED vs LED LCD – Contrast
Take an LCD screen into a darkened room and you may notice that parts of a purely black image aren’t actually black, because you can still see the backlighting (or edge lighting) showing through.
Being able to see unwanted backlighting affects a TV’s contrast, which is the difference between its brightest highlights and its darkest shadows. You’ll often see a contrast ratio quoted in a product’s specification, particularly when it comes to TVs and monitors. This tells you how much brighter a display’s whites are compared to its blacks. A decent LCD screen might have a contrast ratio of 1,000:1, which means the whites are a thousand times brighter than the blacks.
Contrast on an OLED display is far higher. When an OLED screen goes black, its pixels produce no light whatsoever. You can’t get darker than that. That means you get an infinite contrast ratio, although how great it looks will depend on how bright the LEDs can go when they’re lit up.
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Sony’s demo of LCD vs OLED contrast
OLED vs LED LCD: Viewing Angles
OLED panels enjoy excellent viewing angles, primarily because the technology is so thin and the pixels are so close to the surface. That means you can walk around an OLED TV, or spread out in different spots in your living room, and you won’t lose out on contrast. For phones, viewing angles are extra important because you don’t tend to hold your hand perfectly parallel to your face.
Viewing angles are generally worse in LCDs, but this does vary hugely depending on the display technology used. And there are lots of different kinds of LCD panel.
Perhaps the most basic is twisted nematic (TN). This is the type used in budget computer monitors, cheaper laptops and some very low-cost phones. It offers poor angled viewing. If you’ve ever noticed that your computer screen looks all shadowy from a certain angle, then it’s more than likely a twisted nematic panel.
Thankfully, a lot of LCD devices use IPS panels these days. This stands for ‘in-plane switching’ and it generally provides much better colour performance and dramatically improved viewing angles.
IPS is used in the vast majority of smartphones and tablets, plenty of computer monitors and lots of TVs. It’s important to note that IPS and LED LCD aren’t mutually exclusive; it’s just another bit of jargon to tack on. Beware of the marketing blurb and head straight to the spec sheet.
OLED vs LED LCD – Colour
The latest LCD screens can produce fantastic natural-looking colours. However, as is the case with viewing angles, it depends on the specific technology used.
IPS and VA (vertical alignment) screens offer great colour accuracy when properly calibrated, whilst TN screens can often look weak or washed-out.
OLED’s colours have no issues with pop and vibrancy, but early OLED TVs and phones had an problems reining in colours and keeping them realistic. These days, the situation is better – the Panasonic FZ952 series OLED TV is even suitable for use in Hollywood colour-grading studios.
Where OLED struggles is in colour volume. That is, really bright scenes may challenge an OLED panel’s ability to maintain levels of colour saturation. It’s a weakness that LCD-favouring manufacturers enjoy pointing out.
What is the future for LCD and OLED ?
Display makers are doing their best to tweak and improve the various limitations of LCD. While OLED’s job over the next few years is to become cheaper and brighter, we’re seeing more distinct developments in LCD.
Perhaps the most catchy is the ‘quantum dot’. It’s a new way to approach the LCD’s backlight. Rather than using white LEDs, a quantum-dot screen uses blue LEDs and ‘nanocrystals’ of various sizes to convert the light into different colours by altering its wavelength.
Samsung has been rocking quantum dot tech for a few years now, and the company’s latest development actually puts LCD (nicknamed QLED) a lot closer to OLED performance. Samsung has wrapped nanocrystals in a metallic alloy and rejigged the lighting system, which fixes much of the contrast and viewing angle issues associated with LCD panels.
Which tech wins?
That’s a tough one. In terms of sheer numbers, LCD is definitely winning. It’s been around for much longer and it’s cheaper to make, which gives it a head start when it comes to market saturation.
If you’re dealing with a limited budget, whether you’re buying a phone, a monitor, a laptop or a TV, you’ll almost certainly end up with an LCD-based screen. OLED, meanwhile, remains a more luxury proposition.
But LCD’s dominance is slowly being chipped away; OLED tech is gaining momentum. The tech already features in the very best smartphones, and it’s making big waves in the TV world too.
Which is better? Even if you eliminate money from the equation, it really comes down to personal taste. Neither OLED or LCD LED is perfect. Some extol OLED’s skill in handling darkness, and its lighting precision. Others prefer LCD’s ability to go brighter, and maintain colours at bright levels.
How do you decide? Stop reading this and go to a shop to check it out for yourself. While a shop floor isn’t the best environment in which to evaluate ultimate picture quality, it will at least provide an opportunity for you to realise your priorities. Whether you choose to side with LCD or OLED, you can take comfort in the fact that both technologies have matured considerably, making this is a relatively safe time to invest.