Skip to main content

Active vs. passive 3D TV technology: What’s the difference?

TV makers are introducing 3D HDTVs at a fast and furious clip. For example, Panasonic has 14 new ones, Vizio five, LG seven…the numbers keep piling up. Screen sizes range from 32- to 70-inches, and there are enough features and price variations to make your head spin. We’ll leave those specifics for another day. What we want to address is the issue of the 3D technologies you’ll encounter as you don your glasses and gaze at the infamous wall of flat panel TVs at the local store.

The practical difference

Active and passive 3D technology are two rival systems for accomplishing 3D effects, both competing for your money. We’ll get into the mechanics shortly, but the key differences are the 3D glasses supplied with each type of set. Passive glasses are similar to ones handed out at the movies: They’re light, cheap and do not require any power. LG, for example, includes four pair with its new models, such as the recently reviewed the 47LW5600. We reported the 3D experience was quite good, and the price for the 3D eyewear is definitely right.

LG passive 3d glassesLG passive 3D glasses

Active 3D glasses are bulkier, heavier, require battery power and cost a lot more than their passive counterparts. Typically, one or two pairs are supplied with a new 3D TV, while additional glasses cost anywhere from $50 to $179 per pair. Want to invite a bunch of friends over to watch Tron in 3D? Get ready to spend. That said, the quality is better, with much finer detail and the extensive sense of depth one expects from 3D HDTV.

Sony active 3D glassesSony active 3D glasses

How they work

Active 3D HDTV, which uses active shutter glasses, is a sequential system. All 1080 lines of resolution are beamed from the TV display panel to your eyes. An infrared signal paired to the supplied eyewear opens and closes the left and right lenses of the glasses at a very rapid rate, hence the term active shutter. Your brain perceives these fast-moving alternating frames as 3D. The important fact to note is the amount of resolution – 1080 lines. Active models are often labeled Full HD 3D.

The vast majority of passive 3D HDTVs use panels are supplied by LG Display, which operate on Film Patterned Retarder (FPR) technology. The 3D effect is created when the set’s left and right images are viewed with polarized glasses. Instead of active’s sequential frames, it’s an odd/even system and resolution drops to 540 lines to each eye, but you perceive high-def 3D. The glasses do not have to turn on and off; they just rest there “passively.” That’s why they’re so cheap, light and in our view, more comfortable. The system works well, and besides the fact quality isn’t as good as a top-tier active shutter HDTV, they are less forgiving in terms of placement; you really have to be at eye level for the best 3D effect.

What do they look like?

We recently sat through a side-by-side comparison of a new Panasonic plasma using the active system versus a passive 6500 series LG 3D LED LCD HDTV. The difference was dramatic as the detail and effects of the Panasonic looked far crisper and more realistic. A still image was shown of a guitar on both screens. The strings on the LG had jagged edges, and turned into double lines as you stood up and moved off center. The Panasonic held rock steady. We know this is not a true apples-to-apples comparison as plasmas use a faster self-illuminating technology that’s far more responsive than any LCD on the market. This speed is the reason plasma 3D effects have less blur and crosstalk, which you see as double images on the screen. Competitors readily admit plasma has an inherent advantage over LCD because of this faster response time. So if you’re looking for the absolute best quality in 3D as well as 2D, plasma is the way to go. They also admit plasma doesn’t lend itself to passive technology—it’s too difficult and expensive to implement.

panasonic 3d tv family
Image used with permission by copyright holder

The price of perfection

Now the price-versus-quality debate begins. Take a look at that wall of 3D HDTVs and check out new passive models from LG and Vizio. We gave the passive LG 47LW5600 an Editor’s Choice award because the 3D quality is very good, the price is right while the glasses are inexpensive and light. We have absolutely no problem recommending them. And yet active shutter 3D is better, especially on a plasma display. Those in the active shutter camp well know the sticker shock consumers face dealing with the cost of eyewear. That’s why Samsung recently dropped the price of its basic glasses to around $50, plus many of its sets come with two pair of active shutter glasses. You can expect similar price drops from other makers as the year progresses. Competition is a wonderful thing!

See for yourself

It’s hard to make sweeping pronouncements once you start comparing one specific model to another, as features and prices vary greatly. And unless you’re a total video geek you won’t have active and passive 3D HDTVs sitting side-by-side in your house. We’ll get on our soapbox now — it’s absolutely imperative you do a glasses-on comparison of the two technologies, compare features and then find your best price. You might opt for Vizio’s Theater 3D, LG’s Cinema 3D (both passive with lighter eyewear), a Sharp Quattron LCD or Panasonic Viera plasma with active shutter glasses as your final choice. Join an online debate if you feel strongly one way or the other. As for us, it’s all good. We just wish there was more 3D content to watch…

Editors' Recommendations

David Elrich
David has covered the consumer electronics industry since the "ancient" days of the Walkman. He is a "consumer’s"…
This 85-inch Samsung 8K TV has an incredible $3,000 price cut this week
The Samsung QN900C Neo QLED 8K TV in a living room.

One of the best upgrades you can make to a home theater system is grabbing yourself a large and high-end TV, and for that, you may want to consider this massive 85-inch Samsung QN900C. Not only is it one of the best TVs on the market, but it even runs at an 8K resolution, so even if you have it up close, you won't notice the pixel density. Of course, it is an expensive piece of kit, and it usually goes for an eye-watering $8,000, although you can get it from Samsung directly for $5,000, which is a whopping $3,000 discount and probably one of your few chances to grab such a high-end TV for a lower price.

Why you should buy the 85-inch Samsung Neo QLED 8K QN900C
Like some of the other best QLED TVs, the Samsung QN900C is packed with a lot of excellent features, starting with the Neural Quantum Processor 8K, which can upscale your content up to 8K resolution. That's absolutely needed given that there essentially isn't any 8K content available on the market right now, so having an upscaler like this means it's compatible with your current and even older content, although the results will vary depending on the source material. It also comes with Neo Quantum HDR 8K, which is just Samsung's own high-end proprietary HDR, but at least it also supports HDR10+, so you can access pretty much all HDR content.

Read more
Our favorite headphones, Sony WH-1000XM5, are $70 off today
Woman wearing Sony WH-1000XM5 headphones.

With how loud and crowded the world has gotten, having a solid pair of headphones to keep all the noise out can be really helpful. When it comes to active noise cancellation (ANC), our pick for the best headphones on the market is the Sony WH-1000XM5, which easily competes with the likes of the AirPods Max. That said, the XM5s can get really expensive, which is why we're happy to see this deal on Amazon that brings the price down to $329 from its original $400 price, saving you a solid $71, which may not seem like much, but it's a great amount for one of the best headphones you can grab.

Why you should buy the Sony WH-1000XM5
There is a lot to love about the Sony WH-1000XM5, and the excellent audio fidelity is one of them. Ironically enough, it has smaller drivers than the previous generation, and yet it still manages to upgrade the audio quality with a balanced overall sound and a surprisingly great bass response that makes it thumpy but doesn't muddy the sound. Realistically, you can pretty much listen to any genre of music you want on the XM5s, although it does slightly favor those who prefer a more neutral sound rather than something a bit more bass-heavy.

Read more
Staring deep into the anti-glare abyss of the Samsung S95D
Samsung S95D Anti-Glare

From the moment the Samsung S95D OLED made its first appearance at CES 2024, I’ve called its anti-glare, anti-reflection technology a game-changer for OLED TVs. But the moment those words left my mouth, concern that this technology might somehow degrade the picture quality started up.

Since then, I’ve seen the S95D in a couple of other settings, but I’ve always said I would reserve my final opinion until I properly review the TV. And I'm prepared to be proven wrong.

Read more