Tuesday, August 31, 2010

3D Television

One of the things I did manage while I was at Merry Hell was to check out the 3D televisions both at the Sony Centre and Best Buy. I had to wait at the Sony Centre as a group were there, two on the coach and two behind watching; not with the glasses mind just 2D. One of the staff was holding a pair of glasses so from this and the conversation I guess they'd just tried it. I stood I waited, they left and the staff member went to put the glasses away.

Um hello standing here close to the television not moving like to offer me a viewing. Nope I had to ask. I got the glasses and they fitted nicely over my own, the 3D section was cued up and I watched the aquarium demonstration. Yep I can see the 3D effect and it's mildly impressive, or it would be if it wasn't flickering so badly. Terrible, I mentioned this and got "Well it's 200Hz so you're not going to get any better"; excellent.

In Best Buy they had four televisions up an LG a Samsung, a Panasonic and I think another Samsung, but only one pair of glasses LG's. Turns out the kids break them and at £100 a pop not something to leave out and they don't seem to want to keep a staff member on hand to offer them. So great introduction there - kids break the glasses and they're expensive. So one pair means a queue, although that would indicate some sort of order - a bunch would perhaps be more descriptive. One group had a look, then the kid had a look and then the glasses got passed to the next in the bunch which was me, no it got passed to a oriental group instead.

He looked through them as his kid tried to snatch them from his face, the kid used them, then back to the father, as the kid tried to grab them again, then to the kid, then to the father, then to the wife, then to the kid, then to the father, then back to the kid [sigh]. Finally they decided to leave and the father indicated that the kid should pass them onto me. He looked shocked at this as if I'd suddenly materialised next to him. Anyway I  don't know if it was the tuning, but using LG glasses with the other televisions didn't really work, but they were fine with the LG and a lot less flicker than the Sony.

Hmm I wonder if they'd set the Sony ones up correctly?


Orphi said...

Any idea which 3D technology this is?

The local shopping center has a few TVs streaming adverts, and they have a vaguely 3D effect. Of course, for that kind of thing, you cannot possibly use glasses. Instead, it's based on lenticular lenses. So the effect is about as convincing as those 3D “holograms” that you sometimes get in cornflake packages — i.e., not very.

The things in cornflake packets aren't actually holograms at all. You take several images, slice them up vertically, and interleave the slices. You then print that onto a sheet of paper. You then glue that to a sheet of ribbed plastic. The ribs are the “lenticular lenses”. They have the effect that as you look at the thing from different angles, you see a different group of slices (i.e., a different image).

Apparently you can make LCD TVs with these lenses relatively easily. The effect is similar; if you stand in just the right spot, it can look vaguely good, until you move your head. If you casually glance at it, all you really notice is that it's not entirely 2D and looks slightly weird.

True holograms use specialised photographic paper exposed using lasers and so on, and there are several different types. The results are generally much, much more convincing. Indeed, at the London Science Museum, I've seen holograms that are jaw-droppingly real. They're just ****ing expensive to make. And stationary. And monochrome.

I went to see Journey to the Center of the Earth in 3D at the cinema. (If you have the opportunity… don't bother!) This uses glasses with polarised lenses to seperate the image for each eye. It works, but it's surprisingly uncomfortable to watch. I hypothesize because with a real 3D scene, you can adjust the point at which your eyes focus, but with a dual-image delivery system, each camera was pointing in a fixed direction and can't be altered, which confuses your brain.

And yes, they made flying fish jump out of the screen at us. Which is very irritating.

I've also heard about (but never tried) a system that uses two lenses that just alternate between being opaque and transparent, hopefully in time with the screen alternating the image shown. Apparently the military uses it for training simulations, but it's unusable for anything else due to the extreme headaches it generates.

FlipC said...

I know the Sony system uses Active Shutter, which is what you describe for the military. LCD glasses that switch between opaque and transparent so the 200Hz picture is really two 100Hz pictures.

It looks like the LG uses the same system, so why wasn't the flicker as bad? Thinking about it I wonder if it was the fluorescents? Shouldn't have been, but I do find it odd.

I've yet to try the polarised system, in theory that should eliminate my flicker problem at the expense of making the screen darker.

Oh and BTW congrats, all that fuss and worry and it just drops into your lap :-P

Orphi said...

Active shutter pretty much demands that the actual display have a very fast response time. This is quite difficult with CRT systems; the system needs a long response time so it doesn't flicker as the beam scans it. But LCD produces continuous brightness, rather than being scanned. Just got to make sure that the backlight doesn't flicker.

(I was under the impression that a lot of LCD systems use cold cathode flourescent backlights. But Scott would probably know more about it…)

As I say, apparently Active Shutter isn't used much because if you look at it too long, you start to get a massive headache. I wonder how these manufacturers have got around that little problem?

Personally, I suspect that anything requiring glasses will only ever be a novelty anyway. It's inconvinient, especially if the glasses cost a fortunate and are easy to break, or if you happen to be one of these people who need optical lenses to see the real world anyway. I think 3D will only really take off if they can make it work without glasses.

Oh, and thanks. It's the new Andrew 2.0; he's so self-confident he can get with girls almost by accident! ;-)

FlipC said...

Yeah I think the main problem was the cost of the glasses combined with the low refresh rates of CRT. Well the glasses are still expensive, but the refresh speeds have increased; but I at least can attest to the headache inducing qualities of them. Even the LG version I wouldn't want to wear for a long period of time.

Here's the small print from LG's site "For a small percentage of the population, the viewing of stereoscopic 3D video technology may cause discomfort such as headaches, dizziness or nausea."


3D without glasses? Sounds like a job for Nintendo! :-) I wonder if their upcoming 3DS will work for me?

Dan said...

We have a Sony 3D TV at work for making product demos, and I found the glasses really got on my wick after just a few minutes. The thing with the active shutter glasses is that the TV signals them using IR, so if you cover up the receiver on the glasses (as you might do if you're just holding them to your head for a moment instead of putting them on), or if there's a strong IR source in the room, the glasses get out of sync with the TV. This could be what caused the flickering you saw, particularly if they've got a few similar TV's out near each other, all blatting out IR all over the room.

That said, I didn't have any problems at all with the circular-polarised glasses I got for 3D Avatar. And I'll be queueing up for the 3DS when it comes out.

FlipC said...

Hmm well they came out of a case and I put them on and left them there without holding them then watched the demo for about two minutes.

As you say I guess the other TVs might have caused interference... yes possibly the TVs at Best Buy were attached to the far wall whereas the Sony one was positioned centrally with other TVs around it. If that's the case I'm surprised that Sony don't offer guidelines as to placement, or that they've been ignored.