There are few things more overwhelming than keeping up to date with new television technologies. The alphabet soup of acronyms to draw from (including QLED vs OLED? HFR vs HDR? Mini-LED vs Micro-LED?) can easily dissuade even the most eager customer hoping to get the best television for their situation.
In order to help cut through the confusion let’s take a deep dive into some of the more common terminologies and try to make sense of all this jargon.
What is TV resolution?
TV resolution refers to how many pixels make up the picture your TV produces. The number of pixels on a digital display should be the easiest metric to consider. Each “pixel” is a unit of chroma and luminance information (i.e., colour and light), where an image is created by pixels turning on and off many times a second.
In order to generate the wide spectrum of colours within an image, each pixel is actually made up sub-pixels that are themselves individually controlled to generate various hues and brightness intensities.
The difference between old school televisions and new
Old-school television CRTs weren’t resolution-dependent but instead counted their capability on the number of horizontal lines they produced. In North America., they were limited to 525.
Modern digital screens use a fixed grid of pixels. That means you can feed it content from a variety of sources, say an old video cassette or an 8K test pattern, and it will display at the resolution of the television itself.
This can get less straight forward though. For example, displays can have dramatically lower “effective resolution” when it comes to images in motion, as smearing and other artifacts can come into play; so some 8K televisions can actually look worse with moving images than some televisions that are “merely” 4K.
The tech behind SD, HD, 4K, and 8K
As you can see, it’s easy to confuse the source resolution (i.e., the content you actually want to watch) vs the resolution of the TV itself. 4K content on a regular HD TV may well look better than, say, HD on an 8K, depending on the scaling mechanism of the given model.
Perhaps the simplest way of thinking about is that each new HD display format has essentially doubled the number of horizontal pixels, meaning that 4k has twice as many as regular HD, and 8K has twice as many as 4K. Another way is to think about it the way the manufacturers do, where a 4K television is, essentially, four regular HDTVs stuck together in a 2×2 grid. An 8k television is four 4K TVs, or a whopping 16 regular HD screens worth of pixels crammed into a display!
Standard Definition resolution
In terms of content, DVDs had what was referred to as Standard Definition resolution. SD has a 16:9 rectangular ratio (720 horizontal pixels vs 480 vertical), which was a slight improvement over what analog broadcast television or VHS/Laserdisc was able to deliver.
High definition resolution
High-Definition broadcast was introduced with two competing technologies (1280×720 vs 1920×1080), the latter which can be roughly thought of as thousand horizontal pixels and one thousand vertical. It’s the horizontal resolution that gets used, and thus you can think of HD as being almost 2K resolution (K being a mathematical symbol for 1000). Blu-ray discs use the full HD resolution for the majority of their titles.
Ultra High Definition resolution or 4K
UHD (Ultra High-Definition) bumped the pixels number up to 3840×2160, which for convenience is rounded up to be called 4K. The vast majority of premium models, and even many laptops, use 4K panels to display all their content. Most streaming services use a mix of HD and UHD content, and there are 4K Blu-ray discs that allow a much higher resolution presentation on your television.
And then there was 8K…
8K televisions (7680×4320) remain an extremely premium display technology, and there’s an absolute dearth of actual content that can take full advantage of all those pixels. With sixteen times the number of pixels as their HD cousins, these are technological marvels.
One thing to keep in mind right now; there’s almost no 8K content. Any television would have to take whatever signal that’s received and upscale or translate the lower resolution signal to correctly display on its more than 33 million pixels.
The size of the individual pixels are naturally directly proportionate to the size of the TV, meaning that cramming a 4K screen onto your phone will have these dots much closer together (so-called “pixel density”) versus a screen hanging on your wall. While 8K is on its way, and you can buy LCD or OLED sets from the likes of LG, Sony and Samsung, the vast majority of even discriminating viewers will be well served with 4K models for many years to come.
HFR and HDR: Frame rate and an explosion of colours
Moving beyond resolution, there are a few other TV technologies to consider when choosing the best TV for you.
HDR vs HFR
These two technologies provide in many ways an even larger paradigmatic shift for modern displays, and are a much bigger deal for most people than worries about 4K vs 8K. HDR refers to high dynamic range, dramatically expanding the contrast ratio (the max brightness vs the max darkness), and exploding the number of individual colours to number in the billions.
HFR high frame rate refers to high frame rate, and there are two ways to look at HFR. There is the frame rate your TV can produce and the frame rate the content you’re watching or playing was shot in.
While conventional, 8-bit HD shows and discs do a very good job, a properly mastered HDR title is a whole other level of clarity and fidelity to the source, regardless of the resolution. HDR is closer to the way our eyes work (and how film and professional digital projectors as well), truly bringing the magic of the cinema to our homes. Think of the subtleties of skin tone, or the sea of blues and greens of a field and a summer sky and you’ll get an idea of what HDR can provide.
All displays rely on a magic trick of our brains where we can see movement as a series of individual frames changing rapidly. Conventional television signals in North America ran at 60 fields/second, while film standardized back in the 1920s to 24 frames/second (measured in a unit called Hertz, or “hz”). There are inherent artifacts in both these techniques, resulting in what some consider a “cinematic” presentation versus the more “video-y” look of 60hz and above.
Thanks to the push of video gamers, where milliseconds of response time can be the difference between surviving the mission or losing out to a faster reaction time, many televisions now allow for up to 120hz at full resolution. Some content creators like Ang Lee, Peter Jackson, and James Cameron with his upcoming Avatar films are pushing the boundaries of HFR for movies as well, making unconventional-looking films that are often startling in their clarity and absence of motion blur, while disturbing others with their apparent artificiality for those weaned on traditional presentations.
Choosing between LCD and OLED television
For the last decade, the two primary and competing display technologies have been LCD and OLED. Both have their unique strengths and challenges, yet thanks to some remarkable engineering by the leaders in the field the difference are growing more and more subtle.
Both OLED and LCD use light-emitting diodes, which are essentially lightbulbs on individual computer chips, but they do so in fundamentally different ways.
OLED (organic LED) doesn’t have to do anything with the diet these TVs are fed while they’re on a farm; it refers to a self-emissive technology where each individual pixel is controllable and can turn off and on.
It’s not dissimilar to how the “cells” on a plasma used to operate. The huge advantage is that you get perfect blacks on this display – you want to have a dark area then you simply turn off the given pixel, where one right beside it can be at full luminosity. The tradeoff is that you can only drive these individual pixels so much before they’re damaged, meaning that technologies such as ABL (automatic brightness limiting), pixel shifting, and so-on are employed so you don’t inadvertently overpower the TV and age the pixels at different rates.
That aging is what some have dubbed “burn-in.” This means for HDR content you’re not going to get the intense brightness of some top-level LCDs, but you will get the darkest blacks possible. Thanks to major advancements, with protection circuitry and other factors, modern OLEDs are nearly free from concerns about image retention that was a factor in previous models.
While the price has come down significantly, there’s still a premium for this remarkable display technology, and OLEDs only really shine to their full potential in a light-controlled room like a home theatre. For those that want the ultimate for their home theatre OLED remains at the top of most people’s lists.
Liquid Crystal Displays, or LCDs, operate with tiny elements that behave almost like stain glass windows, where a strong backlight shines through the various colour layers to reproduce a given image. The brightness of the TV is only restricted by the power of this backlight, which is usually made up of a series of uniform LEDs shining white light.
The downside is that two pixels right beside each other share some of the same backlight, so for an image like a starfield, for example, you’re going to see a bit of ringing, ghosting or blooming instead of a pinprick of light. Similarly, there’s a bit of a lag in how each colour pixel opens and closes, essentially, meaning that during motion there can be smearing and other artifacts.
The shortcoming of LCD black levels has resulted in a number of impressive advancements including FALD (full-array local dimming). Instead of the entire backlight providing a uniform illumination that results in milky/grey blacks as light leaks out through the darkened pixels, you get a checkerboard-like pattern where individual zones can be turned on or off. This allows the bright part of an image to have the full impact while other parts of the screen are unaffected by the backlight.
One more choice: QLED, Mini-LED, and MicroLED
There’s a bit more to the TV selection process when choosing an LCD TV, especially this year with the arrival of Mini-LED and MicroLED displays.
Looking a lot like OLED from across the store floor, this is Samsung’s cheeky naming for their “quantum dot” technology. These quantum dots help transform the blue light emitted by the backlight layer and convert to a more “pure” red and green, resulting in a better spectral clarity that’s then sent through the LCD layer. Almost every high-end LCD TV from a wide variety of manufactures uses this type of backlight, but the naming from the one manufacturer that’s long been competing with OLED display manufacturers should not be confused with the very similarly named competing tech.
The magic of Mini-LED
Several modern TVs improve local dimming even further, employing much smaller LEDs to allow for thousands of more zones that can be individually dimmed or brightened. The result is a picture much closer to the black levels of OLED, with all the brightness advantages of LCD remaining intact. It’s still not a perfect solution, compared to what are essentially millions of individually controlled illumination pixels on an OLED, but the recent advancements are welcome ones. Read more detail about Mini-LED here.
MicroLED and a fantastic future.
Some manufactures are exploring the ultimate hybrid, where the array of LCDs is controlled by a 1 to 1 grid of back-lit LCDs. This would allow the purity of colour from conventional televisions with the power of OLED’s luminosity control. MicroLED panels are built in small segments and can be strung together like wall tiles into a myriad of shapes, expanding your display in seemingly endless ways.
The implementation of MicroLED is likely years away for most consumers, but it’s an exciting promise where we have the advantage of self-emissive technology combined with the stability and colour fidelity of LCD. Read more about Micro-LED here.
Making Sense Through A Simple Game
Now that you have a handle on all this jargon, it’s perhaps helpful to simplify things down to an almost child-like level. Think of a simple tic-tac-toe grid, where one can place a series of Xs and Os. This gameboard display would have a fixed “resolution” of 3×3. The X can be anywhere from just over black to full bright, and can be any colour we choose, where the O is, ideally, pure black with no light emitted.
If the signal was to use the full resolution of the board you’d be able to individually control each of the nine blocks. On OLED, an X could be right beside an O without any of its colour or light leaking out to its neighbour, but due to the nature of this display technology it cannot approach the brightness of its LCD counterpart.
On the other hand, for LCDs, when a grid slot is marked O some of the light from neighbouring X spots inevitably leaks through. FALD and Mini-LED backlight lighting is meant to help reduce this light spill, but it still means that an O is never as black as it might be with an OLED screen. The dream of technologies like MicroLED is to have each individual square be an X as bright as you’d like, and an O with pure black, thus providing the ultimate contrast. HDR determines how many colours each X can present, and HFR determines how fast each square changes per second.
What TV will you choose?
In the end, this morass of tech mumbo-jumbo shouldn’t intimidate you when selecting your dream television. There are choices to be made, for sure, but most modern televisions produce images that only a few years ago were the stuff of dreams.
There are many considerations to be made outside the tech specs, including where in your home the TV is going to be placed, what you’re going to be watching, and so on. But for those interested in the nitty-gritty of display capabilities this hopefully has given you a good boost and help you make the best out of your buying decisions.
Find your new TV right now on Best Buy.