Why 24fps is not enough for HDR movies

[Rasmus Larsen]

We have reviewed the LG SL8000 (SL80) series in 42-inches. SL8000 has a Borderless Design and scanning backlights.
The review can be found here:
http://www.flatpanelshd.com/review.php? ... 1268298025

If you have questions please use this thread.

Enjoy

[petasis]

Can you please elaborate on the methodology you use to measure contrast?
Do you derive contrast from measurements of 100% windows of black/white (on/off contrast), or by measuring black/white shown simultaneously on the screen, using a chessboard pattern (ANSI contrast)?

[Rasmus Larsen]

We use the ANSI methodology.

It's not really that important on LCD-TVs, though. It's primarily with plasma-TVs that there's a big difference between on/off measurements and ANSI measurements.

[petasis]

I am not so sure that it is not important. I think it is, especially on LCDs. where global dimming can be activated. If you use the chessboard, you measure black & white simultaneously, on the same image shown in the TV. If you measure black/white separately, a TV can dim its backlight.
For example, it is not easy to believe that B7000 measured 0,06 cd/m2 & 188 cd/m2 on a chessboard. On the other hand, the measurements for B8000 are quite different: and they use similar panels. The difference is that B8000 has a black adjust setting, that can turn backlight dimming off. If the B7000 measurements are affected by backlight dimming, one can suggest that measurements have not been done on a chessboard pattern.

So, are you sure that a chessboard pattern is used for contrast measurements? If yes, can you comment on the numbers measured on B7000/B8000?

[Rasmus Larsen]

I am not so sure that it is not important. I think it is, especially on LCDs. where global dimming can be activated. If you use the chessboard, you measure black & white simultaneously, on the same image shown in the TV. If you measure black/white separately, a TV can dim its backlight.
For example, it is not easy to believe that B7000 measured 0,06 cd/m2 & 188 cd/m2 on a chessboard. On the other hand, the measurements for B8000 are quite different: and they use similar panels. The difference is that B8000 has a black adjust setting, that can turn backlight dimming off. If the B7000 measurements are affected by backlight dimming, one can suggest that measurements have not been done on a chessboard pattern.

So, are you sure that a chessboard pattern is used for contrast measurements? If yes, can you comment on the numbers measured on B7000/B8000?

It's true but I was refering to the SL8000 review here on an LG TV. You're talking about Samsung TVs with global dimming.

What B8000 review are you refered to? There's no B8000 review here on FlatpanelsHD. Did you translate our Danish review on FlatpanelsDK?

On B7000 we measured:
Out-of-Box After calibration
Black 0,06 cd/m2 0,05 cd/m2
Brightness 188 cd/m2 119 cd/m2
Contrast ratio 3166:1 2380:1

On B8000 we measured:
Out-of-Box Efter kalibrering
Sortniveau 0,07 cd/m2 0,05 cd/m2
Brightness (lysstyrke) 208 cd/m2 118 cd/m2
Kontrastforhold 2971:1 2360:1

This is very similar. I'm not sure what you're asking?

And yes, we always use the ANSI way. We have been doing this for 5 years now in all our reviews.

[petasis]

Hm, I got confused: I was looking at this review:

http://www.flatpanelshd.com/review.php? ... 1237556675

Which has a title about the 8 series, but it turns out it was for a model from last year...

I am asking about the methodology, because:

a) It is not mentioned in the site what the methodology is, and

b) The fact that you seem to measure better contrast ratios in LCD panels than plasma ones, suggested (at least to me) that you are measuring on/off contrast (because LCDs have much higher "on" (white values) and achieve much higher values than plasmas).

[Rasmus Larsen]

Ohh, I see. That's the 2008 model, yeah

We haven't translated all of our methodology articles and reviews here on FlatpanelsHD and currently they're only available to our Danish users. FlatpanelsHD is relatively new but FlatpanelsDK has been running for more than 5 years.

Black reproduction on LCD panels has improved a lot in 2009 (at least with Samsung's PVA panel tech). But don't put too much into the contrast ratio. Look at the black level measurement instead. Sure, we can measure better contrast ratios on plasma TVs as well. It's just a matter of increasing peak light output (which is possible with most plasma TVs without affecting black levels). The interesting thing is not the contrast ratio itself, though, but the actual ANSI level as you suggest. And that's what you see in all the reviews.

[Rasmus Larsen]

By the way. The B8000 review is available in Danish here: http://www.flatpanels.dk/test.php?subac ... 1255341088

The text is probably nonsense to you but you can see our charts.

I suggest that we start a separate thread with review methodology if you have further questions. This thread is dedicated to questions regarding the LG SL8000 review.

[reactor]

Hi there,

I am a new owner of an LG 47SL8000. It seems very nice, for the time being, but I am quite unsure for one thing... the panel is very slim and where the screen starts there are at some areas permanent white shadows or fadings when the screen is black or very dark. When there are bright colours you cannot see them, but as soon as the colours are getting dark or completely black, you can see at some areas of the panel "White-ish" shadows as though the links of the panel are not well fit together, and light can come through the panel... I read somewhere that this might happen to LCD TV's, so is it something ordinary or I should take it back for replacement?

Is this clouding or what ? Is it normal for LCDs and if yes how much "normal" it is ?
I'm very satisfied with what i see (especially when it reproduces mkvs) but when its getting dark i see clouding especially on the top right corner.

I would be very thankful if you can tell me your ideas.

Thank you in advance.

[Rasmus Larsen]

Is this clouding or what ? Is it normal for LCDs and if yes how much "normal" it is ?
I'm very satisfied with what i see (especially when it reproduces mkvs) but when its getting dark i see clouding especially on the top right corner.

I would be very thankful if you can tell me your ideas.

Thank you in advance.

Minor clouding is pretty normal with LCD-TVs but if it's very visible you should return the TV. Clouding also varies a lot from one TV to another so if you want to replace your TV you might end up with one without clouding or one that has worse issues.
However, I haven't heard much about serious clouding issues with the SL8000 (SL80) series.

Do you have a picture of the clouding?