As a TV buyer today, you‘re faced with an alphabet soup of confusing acronyms and technical jargon when reading spec sheets and sales pitches. Terms like OLED, QLED, full array LED, and more get thrown around freely. And it‘s hard to tell what impact features actually have on real-world picture quality and performance.
One of the most important – yet often overlooked – considerations is the backlight technology powering your TV. Backlights provide the necessary illumination for the liquid crystal display (LCD) panel to actually generate images from the screen. Different backlight designs can significantly influence critical metrics like peak brightness, contrast and dimming capabilities, uniformity across the screen, viewing angles, motion clarity, and more.
In this comprehensive guide, we’ll demystify the most common backlight technologies you’ll come across while shopping:
- Edge-lit LED
- Direct LED
- Full array LED
- Mini LED
- OLED
You’ll learn how each option works under the hood and stacks up objectively based on lab test data. We’ll also cover key strengths and weaknesses and recommend multiple real-world TV models showcasing the latest implementations of each backlight type across varied price points.
Armed with this information, you‘ll be able to confidently identify and choose a TV with the right backlight system to deliver an exceptional viewing experience for your needs – whether that‘s catching every detail of the big game in a bright living room, losing yourself in cinematic films in a dark home theater, or casual streaming in the kitchen.
Backlighting Crash Course – Illuminating LCD TV Panels
Before examining different backlight designs, it helps to understand why LED backlighting is a critical component of LCD televisions in the first place.
The LCD panel which makes up the display contains millions of microscopic liquid crystal pixels sandwiched between polarized glass filter sheets. Each pixel acts like a tiny shutter – it can twist or untwist to modulate the amount of light passing through from behind.
But the liquid crystals themselves don’t actually emit light. For images to be rendered, there needs to be a light source that illuminates the LCD layer from the rear. That’s where LED backlights come in.
LED backlights provide the light shone through LCD panels to create the picture
LED (light emitting diode) arrays emit bright white light from behind the LCD screen. As voltage is applied to each liquid crystal pixel, they twist to precisely control what percentage of that backlight shines through. Varying transmission pixel-by-pixel is what forms a complete image.
Now let’s explore different backlight designs and their impact on real-world TV performance…
Entry-Level Edge-Lit LED TVs
The most basic version used in affordable LCD TVs is an edge-lit LED backlight. As the name suggests, white LED arrays are positioned only along the edges of the screen – generally the bottom.
A specialized optical light guide panel diffuses and spreads this edge illumination somewhat evenly across the LCD layer. Adding more LEDs can increase overall brightness potential.
Edge-Lit Backlight Pros:
- Narrow screen depth
- Lower production costs
- Suitable for basic HD/4K TVs
Edge-Lit Backlight Cons:
- Mediocre contrast
- Visible clouding artifacts
- Few to no dimming zones
Tests of edge-lit models consistently show two major drawbacks compared to more advanced backlight designs:
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Screen uniformity – With light originating only from the edges, it can be difficult to maintain consistency across the entire display. Darkening and bright patches are often visible, an effect called “clouding” or “dirty screen”.
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Contrast control – Most edge-lit TVs have zero to under 20 dimming zones controlling backlight intensity. With such large zones spanning much of the screen, you lose precise control over illumination behind both bright and dark picture areas. This leads to muted contrast and blacks appearing more like gray.
If you’re looking for good picture quality on a tight budget, edge-lit LED TVs can still get the job done. But for better performance in a moderately lighted or darker viewing environment, it’s smart to consider upgrading from the most basic backlight design…
Great Budget Edge-Lit Model: Hisense 55U6HF – $448
Direct LED Backlights – A Step Up for Less Money
Rather than pushing light outwards from the edges alone, direct LED backlights move the LED components directly behind the LCD panel instead. This allows for brighter and more uniform screen illumination.
Direct LED Pros:
- Increased overall brightness
- More consistent screen uniformity
- Lower cost than full array options
Direct LED Cons:
- Contrast still limited
- Visible blooming artifacts
- Minimal local dimming capability
With light originating throughout the display area rather than just the edges, direct LED TVs avoid most of the uneven clouding problems of edge-lit models. You‘ll notice more consistent brightness from corner to corner.
However, contrast and dimming performance remains mediocre on many affordable direct LED sets. There aren‘t enough independent dimming zones to prevent obvious light blooming around bright objects on dark backgrounds. This phenomenon is called "blooming" and can heavily distract from picture accuracy.
For the next step up in contrast and local dimming prowess without a huge price penalty, full array backlighting is the go-to option…
Great Mid-Range Direct LED TV: TCL 55R655 – $700
Full Array LED Backlights – Contrast and HDR Powerhouses
Rather than lighting the screen as a whole unit, full array LED backlights split the display into dozens to hundreds of zones. The LEDs behind each zone can be independently controlled to emit anywhere from very dim to very bright. This is key for enabling refined contrast.
Full Array LED Pros:
- High brightness and uniformity
- Hundreds of dimming zones
- Excellent per-pixel contrast ratio
Full Array LED Cons:
- Increased TV depth/weight
- Higher production costs
With light output carefully tailored to hundreds of areas behind the screen, full array LED TVs can render deep blacks and vivid colors right next to each other with minimal light bleed or blooming to spoil the effect. This precision contrast is also essential for making high dynamic range (HDR) content really pop.
The only real downsides are somewhat bulkier dimensions and higher prices stemming from the extra LED control hardware packed inside. But the visual rewards outweigh these costs for many enthusiasts and home theater buyers.
Until recently, full array backlighting with extensive zone counts was limited to rather expensive flagship TVs. But improved manufacturing techniques are bringing high-performance full array capabilities to mid-range models as well…
Excellent Full Array TV: Sony X90K Series – $1,599
Cutting-Edge Mini LED Backlights – The Pinnacle of LCD TVs
The latest and most advanced LED backlight design is mini LED. As you may have guessed from the name, mini LED TVs utilize teeny-tiny LED diodes just 1/40th the size of normal LED components.
Cramming in these microscopic mini LEDs at extremely high densities allows for spectacular local dimming zone counts reaching into the thousands across a large screen. More zones equals unparalleled contrast precision.
Mini LED Pros:
- Most advanced LED dimming
- Over 5,000 local dimming zones
- Near OLED-level contrast
Mini LED Cons:
- Very expensive
- Increased TV depth
By condensing each illumination zone down to tiny clusters of mini LEDs, these TVs gain incredible control over managing light output across small, specific areas of the display. With the ability to turn down LED intensity behind dark picture regions and crank it up behind bright regions, you get perfect pixel-level contrast without any noticeable blooming effects marring your viewing enjoyment.
The only catch is the intricate mini LED systems with dense zone counts require specialized manufacturing processes that are currently extremely costly. So be prepared to pay a premium for these peak LED LCD performers primed to deliver an exceptional viewing experience.
Cutting-Edge Mini LED TV: TCL 65R756 – $2,500
Self-Emissve OLED Displays – True Pixel-by-Pixel Illumination
OLED televisions may sound like just another variation of LED tech. But they‘re actually an entirely unique class of displays. Rather than relying on an array of LEDs for backlighting, OLED screens utilize completely self-emissive organic material in each pixel.
OLED Pros:
- Self-illuminating pixels
- Virtually infinite contrast ratio
- Wider viewing angles
OLED Cons:
- Potential burn-in over time
- Lower peak brightness
- Very expensive
When voltage hits an OLED pixel, the organic compounds making it up directly transform that energy into light. This means each pixel contains its own light source independent of any backlight. As a result, OLEDs achieve unparalleled contrast by being able to manipulate each pixel across a near infinite range of brightness – from completely off (perfect black) to intensely luminous.
Without reliance on LED backlights that inherently cause some amount of light bleed across zones, OLED TVs also avoid any issues with flashing, blooming or haloing artifacts you see in even the most advanced LED LCDs. The viewing experience is essentially perfect regardless of content or room lighting conditions.
If you have the budget, OLED televisions handily deliver the pinnacle of picture performance available on the consumer TV market today. Their per-pixel illumination and precision contrast control is unmatched.
Just be aware that potential image retention is a tradeoff for susceptible viewers. And super bright, wide-gamut footage reveals that OLEDs don‘t quite hit the same searing peak luminance levels as the brightest premium LED LCDs. For most buyers seeking true cinematic fidelity however, the pros far outweigh these cons.
Stunning OLED Display: LG G2 Series – $2,100
Finding Your Perfect Backlight Match
We‘ve covered a whole range of LED backlight technologies powering today‘s LCD TVs, along with contrast-king OLED. It‘s a lot to take in. So let‘s boil things down to a simple decision flow based on your budget and needs:
Budget buy – Stick with basic edge-lit LED models
Step up on a budget – Choose direct LED for better uniformity
Strong contrast and HDR – Get full array LED with ample zones
Best LED performance – Splurge on mini LED dimming sophistication
Ultimate picture – Invest in per-pixel OLED illumination
Virtually any modern LCD TV will cover the basics fine for casual TV watching. But home theater aficionados and discerning viewers need to carefully factor backlight capabilities into their selection criteria for the best experience. Contrast, color, clarity and pop will all depend greatly on the backlight system.
Keep this backlight breakdown handy while display shopping and you‘re guaranteed to end up with a TV tailored to your priorities. Understanding the technology inside actually gives you tremendous power to cut through branding buzzwords and navigate to a set that perfectly matches your viewing tendencies. Happy shopping!
