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"…
Best AirPods Max deals: New and refurbished for $420
A woman wearing the Apple AirPods Max.

The AirPods Max are Apple’s high end headphone offering, and while they come in at a premium price point, they sometimes make some of the best Apple deals and best AirPods deals you can shop. They offer high quality sound that can compete and even best almost anything you’ll find hanging out among the best headphone deals, and they fit right into the Apple software ecosystem if you utilize several Apple devices. While there aren’t often a lot of AirPods Max deals to shop, there are some out there right now. We’ve rounded them up below, and if you’re looking for a premium in-ear headphone solution by Apple you can also check out the best AirPods Pro deals currently going on.
Apple AirPods Max -- $450, was $549

The AirPods Max are Apple's first attempt at a set of over-the-ear headphones. They got a lot of things right. We love these headphones, even when compared against some audiophile options that prioritize sound quality. The AirPods Max have awesome noise cancelling. Everything Apple learned with the earbud-style AirPods works even better with the cup style of the AirPods Max. Along with great ANC comes a great transparency mode. With a twist of the Max's massive knob, you'll go from complete silence to feeling like you're not wearing headphones at all. The audio on phone calls is great as well, and they pair better with the iPhone than any non-Apple headphones could ever hope to.

Read more
Sonos Roam 2 gets a surprise release alongside an app update
The Sonos Roam 2.

Alongside today's launch of its first headphones, the Sonos Ace, Sonos has also quietly unveiled the second generation of its popular portable wireless speaker, the Sonos 2.

The Sonos Roam 1 launched in 2021 and has been a mainstay on out best best Bluetooth speakers list ever since for its portability, excellent sound, and Bluetooth and Wi-Fi connectivity, which allows it to connect to your Sonos network system. The second generation of the Sonos Roam remains largely the same (which isn't a bad thing), except for a couple of key features.

Read more
Best AirPods Pro deals: Get Apple’s flagship earbuds for $120
The Apple Airpods Pro in their charging case.

If you’re in the market for some of the best wireless headphones, Apple’s AirPods lineup is a great one to turn to. It’s worth shopping AirPods deals no matter which model you may be looking for, but if a premium in-ear set of headphones sounds right for you, the Apple AirPods Pro are worth checking out. They ordinarily make for some of the best Apple deals to shop, and while the only AirPods Pro deals available right now are on refurbished models, they offer some impressive savings and are backed by quality retailers. Read onward for the details on how to save on AirPods Pro right now, or save on similar headphones by shopping the best headphone deals, which include Sony headphone deals and Bose headphone deals. Apple also offers an over-ear premium headphone option you can find discounted in the best AirPods Max deals.
Apple AirPods Pro (refurbished) — $120, was $220

While there’s a newer model of AirPods Pro available, the first generation Apple AirPods Pro can still hold their own against some of the best wireless earbuds. Made for a slightly more premium user than something like the Apple AirPods 3, the AirPods Pro have higher end features, including active noise cancellation and a transparency mode, which allows you to hear and interact with the world around you while you have the headphones on. Spatial audio with dynamic head tracking is another impressive feature. This makes watching movies and other content a truly immersive experience. This refurbished model of the Apple AirPods Pro comes with free 30-day returns and a 1-year warranty.

Read more