Keep 3D active or make switch to Passive 3D TV - Page 4

It looks like LG has a new 55" 3D Passive TV http://www.avsforum.com/products/lg-cinema-screen-55lm7600-55-inch-cinema-3d-1080p-240-hz-led-lcd-hdtv-with-smart-tv-and-six-pairs-of-3d-glasses that adds 240Hz simulation like the Vizio M3D651SV.

I wonder if a 65" version is coming soon? (There isn't one yet at LG's Webpage.)

Per the CNET review http://reviews.cnet.com/flat-panel-tvs/lg-55lm7600/4505-6482_7-35118094.html it appears to be better in some ways from the current models, but has a serious "hot spots" problem.

I don't trust CNET as far as I can throw them.

It's not just CNET's reviews; the readers'/owners' comments confirm the pluses and minuses.

I'm not saying anything about the TV, I haven't seen it (although I did look at one of LG's 55" models in Best Buy today). But they absolutely slammed my PC monitor as some of the worst 3D implementation that they'd ever seen, and it was 100% wrong. The guy doing the review literally didn't understand how FPR works, and he wasn't even in the right viewing position, then complaining about ghosting and crosstalk and "shallow" 3D (which is supplied by the source, not the monitor, another indication that he didn't have a f'in clue what he was talking about). The big problem is that every other review site on the internet just cut/pasted their review and called it a day. Wouldn't surprise me if that one review singlehandedly killed off the chances of this monitor ever having decent sales (when in fact, it's quite good, and a good price, too).

Since then I've made it a point to look at these things in person.

I hope you're right, because if a 65" version of this comes out soon, it will be at the top of my list of TVs to get, unless the Vizio at 1/2-1/3 the price is nearly as good (if I can see both in person).

But if the tax cuts don't get extended and my taxes, like the average family, go up $300 per month, then the TV becomes a wish and we'll be back to watching SD TV channels as well as we cut/reduce our cable bill or anything else we can.

The bigger and bigger passive sets get the worst they look their already at a 3d resolution disadvantage compared to active. For bigger displays I would for sure go active.

I agree... I have a 55 and think at 42 it would be fine for normal seating distances (let's face it, as you get bigger TVs you don't actually sit back further... pretty much everyone sits 6-10 feet from their set and it stays that way) at 47 it's probably going to be a big of an issue, at 55 inches I find even as far away as I can get in my seating arrangement (about 9 feet) you can still tell the scanlines etc are there. After a few weeks I have gotten used to it and the picture looks fine but I still catch myself noticing the aliasing especially on overlay graphics (like avatar's video recordings etc). And that's with 1080p ou or BR materal... if it's SBS you end up with a notably soft picture all around (as it's basically 960x540 which is only slightly better than DVD resolution and that's not even factoring in the scanline issue).

It's really unfortunately as I relaly like the image clarity and color pop with the passive set compared to the Active glasses setups I have used, but you do definiely trade off in PQ one way what you gain in another....

All of this passive resolution disadvantage is nonsense.

I constantly see people say it's not true it's not true 1080p, or only half the resolution of active 3d.

Here is how it works.

Active: shows 1080p resolution but only shows it in 1 eye at a time. While 1 eye sees the full resolution, the other eye sees a black shutter.

Passive: shows half the resolution in 1 eye, and simultaneously shows the other half of the resolution in the other eye. Both eyes see it at the same time (the same way they do in real life) do your brain still sees the full resolution.

I would personally rather have both eyes process the image at the same time. And every single pixel that shows up on an active set shows up on a passive set. The "half resolution" argument is bunk.

I have owned both an active Samsung 55es7500 and a LG 55lm8600. Passive definitely had lower resolution, I'm not sure I would call it half, but it did make edges softer and the overall picture less defined. Try a half side by side movie and you will see the biggest difference. I'm a gamer so I prefer active's sharper picture. If I was interested in movies only, I could have lived with LG passive as long as 3D content wasn't half side by side. It's not a viewing distance issue either, I was 12 feet back from both TVs. If some people have trouble seeing the difference between 720p(1280x720) and 1080p(1920x1080), then I think it's safe to assume that the difference between active(1920x1080) and passive(1920x540) could go unnoticed as well. At 55" I think the difference is quite noticeable.

Passive is not 1920x540 anymore than active is 0x0.

Again, you see that 540 out of 1 eye, and you see the other 540 out of the other eye, at the same time (the same as real life, both eyes at the same time create the 3d image).

With active one eye sees 1080 while the other eye sees a black shutter. So if we're only counting the resolution from 1 eye (which is the only way you can say passive is only half resolution) then it would be just as accurate to say active resolution is 0x0, since one eye will always be seeing a black shutter.

Again, every single pixel displayed on an active set will also be displayed on a passive. This is fact, not debatable. The only debate is if you prefer it spread across both eyes or only given to 1 eye at a time. I prefer both eyes. Some people prefer 1 eye at a time. Either way is fine. Just make sure if you post your reason for preferring 1 over the other, the reasons given aren't factually incorrect (like the half resolution nonsense that prompted my post in the first place, which I'm not saying we're your posts).

Riddle me this, Terry Bogard. How come when watching 1080p 3D content on active, the picture is just as sharp and clear as 2d? When watching on passive, the image is softer and less detailed. My friends and I all experienced this going from one set to another. If this is not due to a drop in resolution, what else could it be? Is it an issue with interlacing 3D technology? Whatever the case, the detail is better on my Samsung active set than is was on the passive LG. Passive's advantages are crosstalk reduction and a tiny bit smoother 3d motion, from my experience.

Tons of people have tried and failed to explain why passive does or doesn't suffer from resolution degradation.

Simply, the closer I sit to a passive 3D set, the more noticeable the aliasing, blockiness and dark horizontal scanlines are. Aside from viewing distance, the perceivability of these artifacts will also depend on the content, screen size, sharpness level, and lastly, the person.

I don't know why you had issues with your set. I can tell you one thing though, it wasn't because the resolution was only half of an active set.

Maybe your set was defective or had issues? Maybe the other tv is just better quality? I don't know. But I do know if you're seeing 540 out of 1 eye, and a different 540 or if the other eye (at the same time) that combines to be 1080.

If it was half resolution, it wouldn't just be a fuzzy picture. There would be stuff cut out of the picture altogether.

For what it's worth, mine (passive) isn't any more or any less clear in 2d or 3d. There are the lines if you sit too close (previous poster mentioned) but I can watch a 2d movie, hit the 3d button to convert it to 3d, and everything that was in the 2d picture is still in the 3d picture. And I get to see it in both eyes.

If you want to get technical, active technology would not be considered real 1080p. It's more like 1080i. I know it's "officially" considered 1080p, but if you're familiar with what 1080p and 1080i are and the differences between them, you'd have to agree that passive is more "p" and active is more "i" by nature.

There was nothing defective about it. You can see the difference in best buy demo models also. Maybe your TV is 42 inches or below? If you can't see a difference, that's great. I'm not going to be the one that shows you flaws in your TV that you don't see currently. One of my buddies likes to point out dead pixels and other people's TVs and it usually doesn't end well If you enjoy your TV, that's all that matters.

With persistence of vision, we perceive the image in each eye to be constant. What you describe is important in terms of possible flickering and motion handling, and these are real issues, but it doesn't affect resolution. What you're saying is like complaining that DLP doesn't have good color because it only shows you a single color at any one time. That's how the technology works but with persistence of vision we see full color (though with the cost of possibly seeing rainbows).

To understand the resolution differences between passive and active, I think it's most important to understand that 3D is seeing two different images at once. Passive gives you 540 out of the left 1080p image and 540 out of the right 1080p image. You can say that 540 plus 540 is 1080, but it's a 1080 formed by throwing out half the pixels. If the left 1080p image and the right 1080p image are nearly the same then that's fine, you'll get in your right eye what you missed in the left. But if the two images are the same, it's 2D. The more 3D you have, the more the left and right images are different, and the more detail you'll use. I'd recommend giving the whole thread a good read, especially paying attention to the diagrams I posted.

My tv is 55 inches.

Let's break this siren what you said here. You basically said you ate getting the "i" display, not the "p" display. You also said that with an active display you are only seeing the same 1080 resolution as a passive display, but your mind perceives it to be double.

So let me point out that yes, with passive each eye only gets 540, and with passive each eye gets 1080. And let me also point out that each eye sees them at the same time with a passive display, and they don't with an active display. So with either of them, you get 1080 displayed at once.

What you didn't consider (at least you didn't in the post I quoted) is that each eye gets the image refreshed twice as fast with a passive display than they do with an active display.

So, if it's okay for an active display to show a black shutter half the tube because the eye perceives the image the whole time, then it also must be okay for each eye to show, as you put it, "540 pixels of the left image" and then show the other "540 pixels of the left image" while the active would be showing a black shutter.

PS, someone please report that there is no way to edit a post from Tapatalk.

Stop trying to think this out in words and theories and just go LOOK at a damn passive TV. The pseudo-intellectualism is getting to be a bore.

Okay man, I was trying to read the whole thread, as you suggested, and this is as far as I could get without responding.

You are wrong here. You are making a mistake by not factoring in that each eye is not seeing the image in an active set. So there is really only 2 million pixels displayed at once, just like a passive.

It then displays a different 2 million pixels for the other eye. At at the same time the active is doing that, the passive is displaying a different 2 million pixels for both eyes.

You see the same pixels with each display. You see them in only 1 eye on the active, they're spread across both eyes at the same time in the passive (and refreshed twice as fast).

I understand your whole "the mind doesn't see the black shutter of active, and perceives the image as constant" argument. But if you're going to say that, then you also have to say "the 2 images refreshed twice as fast in passive us just as good as the 1 image that alternates with a black shutter in active, because the mind also perceives that as constant."

Hopefully my phone doesn't have any weird auto corrects that I haven't noticed in this post that Tapatalk is not going to let me edit.

I have one that I watch every day. I'm waiting for someone to tell me what content is missing so I can prove them wrong.

Cutting resolution in half means cutting out half the picture. I can promise you this isn't happening.

HowlinWolf, when you say the passive refreshes, are you referring specifically to LG's method of alternatively displaying odd and even 540 lines in each eye? Theoretically that would allow you to see all the pixels of video data available, but half of them would be layered on top of the other. More importantly, there's a link, if you keep reading the thread, that shows that the LG TV has to filter out some vertical information in order to avoid judder. So, you're still losing details.

Doesn't mean you don' have a great TV though.

No, I'm not talking specifically about LG. I'm talking about how active shows a picture in 1 eye, then a black screen while it shows a picture in the other eye.

Passive shows 540 in both eyes (for 1080 total), then (while the active is showing a black screen) passive shows the next 540 in both eyes.

Active displays are switching 120 times per second, 60 flashes per eye, and Blu-rays are only 24 frames per second. There's no missed frames. When a frame changes, with an active display one eye will have to wait a short instant to see the next image, and this leads to motion tearing, but it doesn't miss the frame. The difference is significant, but significant to motion handling, not resolution or detail.

Since these are extreme closeups you should move back so you can't see the pixels in the second image.

I took one photo of each individual left and right lens view, then made them into a crosseye stereo image.


I then blended them together into a progressive image, and cloned it so you could maintain a cross-eyed comparison:


To my eyes, the progressive image looks leaps better than the interlaced stereo-fused LR images. If you see it differently or disagree with my methods, please let me know.
Edited by cakefoo - 12/10/12 at 10:22pm

I understand that. My point is that while the active display is switching, the passive display is showing the supposedly missed pixels. There is no missed information with passive displays.

I'm not sure I fully understand what you did there, or what you're trying to show in doing it.

So are you comparing those 2 images, presumably from a passive tv, to the one image you would see if it was an active tv? If so, where is the one active image?

Or are those the 4 passive images you would see (2 left, 2 right) in the same amount of time as you would see 2 (1 left, 1 right) on an active tv?

Or what exactly am I looking at there and what is it supposed to be showing me?

I re-uploaded the first image. Please take it out and replace it before you compare the two.

The example has nothing to do with active shutter.

If you cross your eyes, the first image is what you'd see on a passive display, and the second image is a deinterlaced version of the first.

What it proves is that, while yes, the odd and even rows theoretically form a full resolution image, the method of taking it in via two separate eyes and fusing it in our brains results in a sub-par image.

Then you are talking about the LG method. Perhaps other manufacturers use the method too now though. As I said, it was shown that the TV has to filter out some vertical detail for this to work. Because the polarizing filters on the TV are physical, unchangeable things, the missed lines have to be shown with the same pixels that showed the first 540 lines for each eye, effectively overlapping them in the same eye. Without filtering out some of the vertical detail, you would see vertical judder, the appearance that the image is subtly vibrating up and down. This might still be better than not showing the missed lines at all, but there's still some detail lost to achieve it (and the black lines are still there).

One thought about cakefoo's image. Indeed, all the detail in the original image is present in the fused image despite being half in each eye. So image fusion works! But note that it's a flat, almost completely (or completely?) 2D image. The flatter the 3D image is, the more image fusion will work. The more depth, pop, and 3Dness the image has, the less it will work.

I'm on my phone so I can't do it. But your method is flawed because passive shows twice as many images as active. And it does it at a speed faster than the human eyes can decipher. Our ad the other guy described it, the brain perceives it as part of the first image.

So for you to duplicate it here, the inky way to get close would be to take the screen shot, then take a screen shot of the next frame, and fusing them all together.

Either that, or showing the first image you displayed and comparing it to the black screen you see half the time with an active display.

Where you guys are making your mistake, is your saying the black screen in an active display doesn't matter because the human eye can't see that fast (so the brain perceives it as a constant image), but then your not counting the next frame of the passive display, even though the eye can't see that fast and the brain sees it as part of the same image.

So take just the left eye for example. An active display will show a left image at 1080, then a black screen, then another 1080 image, then another black screen. The black screens don't matter because it's faster than the human eye can decipher, so the brain perceives it as a constant image.

In that same amount of time, a passive tv will show a 540 image, another 540 image, another 540 image, and yet another 540 image. This (like the black screen of an active display) happens faster than the human eye can see, so the brain perceives it as the same image.

Either way, at any given moment there are the exact same amount of pixels being seen by both technologies.