3D TVs

debbyjg

Was taking a big box thing out of grans garage lol. Well it did say any.

MilkyJoe

If your old TV is worth less than £150 could you not just do it?
Did no amount of haggling work? Surely if it meant the difference between the sale or no sale of a £1000 TV they might budge.
Would selling your old TV and buying on the internet with cashback not work out better?

MilkyJoe

debbyjg wrote: »

Was taking a big box thing out of grans garage lol. Well it did say any.

Oh. :rotfl:
Could you not just look at it as you're getting £150 for a big old box?

Esqui

I probably know way too much about how these work

Active 3DTVs show full "left eye" picture, followed by a full "right eye" picture, followed by the next full "left eye" picture and so on, normally about a hundred times per second. The glasses you wear have lenses which sync with the picture the TV is showing, so that when the "left eye" picture is on the TV, the right eye lens is blacked out, so that only the left eye receives a picture. By doing this so many times a second, your eyes both get different pictures, which creates the 3D effect.

For passive 3DTVs (the LG rep says they shouldn't be called passive, they should be called Cinema 3D...the LG rep is lovely ), the image is arranged so that, for example, the first vertical row of pixels has the left eye's image, the next has the right eye, the next has the next row of left eye and so on. On top of this is a polarising film, which works with the polarising glasses so that the lens on the left eye only lets through the picture for the left eye, and the lens for the right eye only lets through the picture for the right eye.

Fun thing to try, if you have some of the polarising glasses...look backwards through them at TVs. Plasma TVs can be viewed fine, but LCD TVs go completely blank.

MilkyJoe

Esqui wrote: »

Fun thing to try, if you have some of the polarising glasses...look backwards through them at TVs. Plasma TVs can be viewed fine, but LCD TVs go completely blank.

Cool (sort of). Just tried that with some glasses from the cinema. The screen went black. Why does that happen?

MilkyJoe

Well, not completely black, but I could hardly see it. Which begs the question: Why don't non-3D TVs display 3D images?

aliEnRIK

MilkyJoe wrote: »

Why don't non-3D TVs display 3D images?

Because 3D content runs at different Hz to normal (normal being 24, 50 or 60Hz)
3D is generally 120Hz

MilkyJoe

aliEnRIK wrote: »

Because 3D content runs at different Hz to normal (normal being 24, 50 or 60Hz)
3D is generally 120Hz

Why wouldn't a non-3D 120Hz+ TV work then?

Esqui

Non-3D TVs cannot show 3D content using any of the decent methods - they can't alternate between two images, and don't have polarisation to send two different images to different eyes.

Theoretically, they could do it with red/green 3D filtering, but that would look quite rubbish.

MilkyJoe wrote: »

Cool (sort of). Just tried that with some glasses from the cinema. The screen went black. Why does that happen?

Because of the polarisation on the glasses. What you're seeing is what happens when you look, for example, through the right-hand lens at the left hand image - the left hand image has a polarising filter which causes it to go black when viewed through the right hand lens

aliEnRIK

MilkyJoe wrote: »

Why wouldn't a non-3D 120Hz+ TV work then?

Because the tv doesnt accept a 120Hz signal, it just doubles the 60Hz and interploates the middle frames (or not, a lot of times its better to switch the interpolation off)