: Passive 3D vs. active 3D

2011-11-08, 01:38 PM
Hello friends,

I was in Bestbuy few days ago and found LG 3D tv on demo. I learnt from sales rep that LG was using passive 3D technology. Due to passive 3D technology, the glasses are very light and cheaper.

What are your thoughts on new LG 3d (passive) TVs? Is passive 3D is the way to go or no?
I will appreciate your feed back.

2011-11-08, 01:45 PM
Have you searched the forum as there have been several discussions on the competing types of technology already.

IN a nutshell: Passive use polarized 3D glasses, like the kind found in movie theaters. They are much cheaper and certainly lighter. Active 3D will give you better quality image on a plasma tv. I have never seen 3D on an LCD that didn't have ghosting.

2011-11-08, 01:51 PM
Thanks for your reply. I did search forum under 3D or passive 3D but could not find much. But from your reply it appears that plasma is the way to go.

2011-11-08, 01:52 PM
Here is a great study :

2011-11-08, 01:57 PM
avengingange, thanks for providing the study.
Great study and gave me lots of info on the subject now.

2011-11-08, 02:46 PM
I bought one of those LG Passives. While the glasses are cheap, the resolution is halved, thanks to the 3D technology.

Needless to say, that LG went right back, and I bought an active 3D Plasma.

2011-11-08, 04:03 PM
That study was with LCD televisions and Active Shutter glasses so I am not surprised at the conclusions. As I noted, I would never watch 3D on LCD. Every one that I have seen to date has significant ghosting

2011-11-11, 10:04 AM
What very few people talk about is that you can do a lot better than just use the cheap flat-lens glasses you get with your passive TV or from the cinema (RealD and Masterimage). Several companies now make much nicer glasses and those with curved lenses and frames realy help reduce reflections in the back of the lens - a real problem with the cheapie flat-lens styles you get in the box. Polaroid Eyewear, Gunnar, Oakley all have nice styles that perform well. Prices range from $30-$100 depending on your taste - sounds a lot but you can use for any passive TV and for cinema 3D (RealD and Masterimage systems).

2011-11-11, 06:57 PM
I had a C7000 series plasma (2010) and had it replaced yesterday(defective) with a C8000 and boy am I sure a lot happier with Active Shutter than I used to be. The glasses are much lighter, sleeker and cheaper than last year. The basic Bluetooth battery powered glasses for $50 are way more comfortable and smaller than the $179 (back in May) rechargeable IR ones for the C7000. I am not sold on the $80 rechargeable headband type...they are flimsy and awkward, but we'll see. The 3D worked okay on the C7000 but there was some crosstalk and some content was hard to watch...particularly "Wild Ocean" (the beginning Nokia animated short and the motion of the people and birds during the film) and Gears of War 3 (the subtitles really seemed to screw up the 3D image). I tested these out on the C8000 as well as a few parts of "Grand Canyon Adventure" where I noticed ghosting on the 7000 and there was a large improvement.

Another person in my family has an 55" LG passive and it seemed fine (watched part of Tron). I like the glasses, however I still think Plasma has the best picture (and obviously better for motion without having to use frame interpolation). The "half-resolution" argument seems to be mute. I haven't read one review where someone talks about a noticeable difference. I would be more concerned about the viewing angle which is worse with Passive. Active Shutter is 1080p to each eye, whereas Passive is 540p to each eye but still a 1080p picture overall once your brain puts the two images together. I don't think you can say your getting 2x the resolution of 1080p with active shutter though so something isn't logical there.

2011-11-12, 02:47 PM
I agree on the viewing angle on the LG passive series - one of other reasons why it went back to the store, but it is right there in front of you with the ability to see and make out the scan lines, thanks to it being only 540p. The manufacturer says the exact same thing - 540p+540p=1080p. To the average consumer, it sure sounds right, but to you and me, it's not.

Michael TLV
2011-11-12, 10:58 PM

Much like how interlaced TV sets could display an image that looked "sharper" than a progressive scanned image of the same size or less ...

Case in point ... a 36" CRT tube set handled SD signals better than a smaller 27" LCD display showing things progressive. Usually ... images look better on the smaller set but what is the difference here?

The interlacing.

When presented with images that have a scan line structure that the eye can readily see, the brain actually interpolates a full frame image that is crisper than what is actually displayed. A white wall presented to a test viewing group first as interlaced video and then as progressive video will always have the group claiming the interlaced version is somehow sharper to look at ... more detailed.

The passive displays make up for this missing resolution by taking advantage of the brain interpolation that happens. That actually narrows the resolution/perceived resolution gap. Passive 3D also ends up looking crisper than the Active stuff when both images are set up correctly.

(Of course I just got a massive headache at the 2/3 point of watching a 3D presentation of Captain America on my LG top of the line LED/LCD model from 2010. Active shutters all the way ... and the down side to them.)