Contrast Ratio

[biferi]

I am Looking at the LG 75 Inch 4k UHD Smart TV.
Model 75un7070PUC

It has a Contrast Ratio of 11,000 : 1. am I Right that this is to High?

Is this when the TV Fakes it?

Or am I missing something?

[davexnet]

Where did you see that spec? The spec on the rtings site says 1100:1, which is low

look here for some more info
https://www.rtings.com/tv/reviews/lg/un7000
https://www.rtings.com/tv/tests/picture-quality/contrast-ratio

I don't think this TV has local dimming, it's an IPS screen, so the contrast ratio tends to be low.

I bought a budget LG in 2017, it's still working fine, still getting software updates
(updated to version 6 of WebOS last week) but no disguising the fact that the picture
is and was mediocre, poor color accuracy being the most obvious to me, disappointing out-of-the-box
experience due to the choices made on their picture defaults.

[biferi]

So should I Look for a 4.k TV with 120 Frame Rate?
And a contrast Ratio of 1,000 : 1.?

Or what should I go for if it is a 4. k HD LCD TV?

And should I go for a Type or name?

Thanks for the help.

[davexnet]

So should I Look for a 4.k TV with 120 Frame Rate?
And a contrast Ratio of 1,000 : 1.?

Or what should I go for if it is a 4. k HD LCD TV?

And should I go for a Type or name?

Thanks for the help.

What is your budget? Have a look here, they have some recommendations for different price ranges
https://www.rtings.com/tv/reviews/best/tvs-on-the-market

[biferi]

Well I See a Contrast Ratio os 3,000 : 1. is good.

Then I See this does not go for every TV.

But I did Look up what is Static and Dynamic Contrast Ratio.

Is Static Contrast Ratio when the Contrast will change on every Frame?

[davexnet]

https://en.wikipedia.org/wiki/Contrast_ratio

[Cornucopia]

The reality is that there are as of yet NO TVs or consumer displays of any kind anywhere that have that high of a contrast ratio (10000:1+).

There may be some special-use scientific monitors that high, but that is it.

Current UHD HDR-capable displays reach up to 4000:1, compared to SDR displays which historically were somewhere between 100:1 and 1000:1, but only in the last decade were capable of >400:1.

Also, current HDR specs expect that 4000:1 ratio to be a rare outlier in image reproduction.


Scott

[davexnet]

The reality is that there are as of yet NO TVs or consumer displays of any kind anywhere that have that high of a contrast ratio (10000:1+).




Scott

What about OLED ?
rtings classified their rating as infinity:1,
since you can have pixels with full brightness next to pixels that are completely off

[Cornucopia]

(note: there have been a number technologies where pixels turn completely off for pure black)

but...

turned off black pixels are only as black as their surrounding environment.

assuming environment is very dark windowless room, that is pretty dark. hence the practice of movie theaters.

but how BRIGHT the pixels can get is still constrained by current technology, including OLED. and there is no such thing as infinite contrast, not in manmade displays, not even in real life. on earth, the max ratio is ~10 to the 9th power : 1.

don't believe all the marketing bs you read.


Scott

[davexnet]

(note: there have been a number technologies where pixels turn completely off for pure black)

but...

turned off black pixels are only as black as their surrounding environment.

assuming environment is very dark windowless room, that is pretty dark. hence the practice of movie theaters.

but how BRIGHT the pixels can get is still constrained by current technology, including OLED. and there is no such thing as infinite contrast, not in manmade displays, not even in real life. on earth, the max ratio is ~10 to the 9th power : 1.

don't believe all the marketing bs you read.


Scott

Well it's partly marketing, but also the current state of the art -
so allow them to be a little grandiose in their terminology - happens all the time
as I'm sure you're aware. Not meant to be taken literally.

[jagabo]

The contrast ratio reported by manufacturers has little basis in reality. If you normally watch TV in a darkened room you want a TV with a dark black level. You don't care too much about how bright the picture can get because most HDTVs can deliver enough brightness for a darkened room. If you normally watch in a very bright room you don't care too much about the black level -- ambient light reflecting off the screen will be brighter than the black from the TV. Here you care more about how bright the brights can get. Use values reported by independent third parties, not the manufacturers.

[davexnet]

The contrast ratio reported by manufacturers has little basis in reality. If you normally watch TV in a darkened room you want a TV with a dark black level. You don't care too much about how bright the picture can get because most HDTVs can deliver enough brightness for a darkened room. If you normally watch in a very bright room you don't care too much about the black level -- ambient light reflecting off the screen will be brighter than the black from the TV. Here you care more about how bright the brights can get. Use values reported by independent third parties, not the manufacturers.

I agree with this, which is why rtings as well as the 4KTV sub-reddit are well followed by enthusiasts

[Cornucopia]

Their scientific methods are flawed.
As per their page on contrast ratio: brightness of white point / brightness of black point. Seems on the face of it ok. But if you say black point has no signal with OLED that means they are putting ZERO in the denominator making any number in the numerator not matter because the ratio would be equivalent to Infinite.
Except as I already noted, the black point of zero output still has in reality a black point above true zero due to some ambient/environmental light. If they aren't taking that into account, they are not basing their scales on true science or reality.

Scott

[davexnet]

You're just being pedantic. Technically you may correct, but this whole area of trying to describe this picture aspect and how it relates to overall picture quality is already fraught with difficulties. The OLED is The state of the art right now, they're just trying to differentiate so that average readers can understand how OLED is different from a typical back-lit LED. They're not trying to deceive anyone.
How would you like this property of the picture to be described in the reviews. Do you feel buyers are being cheated that this small technical detail was not mentioned?