contrast ratio

[MikeDuke]

I guess this question belongs here.
Is there a minimum requirement of contrast ratio? For ex what is there a minimum it can be and still display a full range of light whites to dark blacks. Is something in the 4000:1 range "good" enough if the screen is say, 42 in? But the replies to not have to limited to that question. A full discusion on contrast ratio is welcome

 

[cjfrbw]

You should always try to see to the screen. I just got a Samsung LCD that has a "dynamic" contrast of 8000, and it is plenty "good enough", though it wouldn't challenge the black levels of a plasma, it has good shadow and highlight detail and saturated colors without paying attention to over gray black levels. I think 4000 is low, and although TV has advanced enormously over the past couple of years, you might see the blacks as annoying and a little bright or washed out. Contrast is quoted in different ways with different sets, but for an LCD, dynamic contrast of at least 6000 on a larger set would be desirable, with dynamic contrast at 10,000 an above as much as you would probably care for. Most plasmas have excellent black levels inherently. With projectors, you would want contrast of 15000 or higher. The larger the screen, the higher the desired contrast.

 

[cjfrbw]

At that screen size, you would probably want a minimum "dynamic" contrast of at least 8000.

 

[MikeDuke]

Thanks. I have the Panasonic 42G25 . I like the picture very much. My calibrator told me that my contrast ratio was 4123:1. I am assuming that is not Dynamic. For me, in my room it can render dark sceens very well. I don't know what the "dynamic" would be. I was just wondering. So, in reality, most people would think the number I posted is low. Again. maybe I am not that sensitive to it but in my room, with my lighting and my seating distance, I am happy. I was just wondering if there is a "standard" that people look for.

 

[cjfrbw]

One of the points of confusion is that the contrast ratios are all measured differently. A calibrator probably would probably measure the inherent, "static" contrast ratio of the panel. An inherent figure of 4000 could look quite good on a panel TV, and could correlate generally with a "dynamic" ratio of 15000 or better. I don't think I have seen a plasma that was manufactured in the last two or three years that didn't have very nice blacks. I have a sony 40 inch KDS LCD tv with contrast of "3000" and I don't have any problem with the blacks, even though they are obviously better on more recent sets.

 

[MikeDuke]

Thanks for the reply. I know that the calibrator uses top flight equipment. I think what gets people all excited is the Dynamic Contrast ratio. My TV is said to have a Dynamic contrast ratio of 5,000,000,000:1. But what they don't tell you is that it only is like that in Vivid mode which most people think looks really bad. I was going nuts reading all the specs for all the different TV's. I was becoming paralyzed with information overload. Now I just relax and enjoy my TV .

 

[cjfrbw]

It would take a lengthy amount of time to review all of the tomes of controversy about contrast on the videophile sites. True videophiles seem to be so picky that they will retch at the slightest deviation from "perfection", whereas the ordinary viewer might marvel at the same picture.
The ultimate test is the "bat cave", the room with a 100 inch or larger diagonal picture in a completely dark room with non reflective, dark surfaces.
Bat cave conditions probably require viewing dynamic contrast of 30,000 or better.
Most standard commercial movie theaters are not "bat caves", and this is where home theaters actually exceed the quality of standard movie theaters.
For standard panel displays in rooms with moderate to low light, or even reasonably dark conditions, dynamic contrast in excess of 10,000 is probably good enough for most viewers.
Just like audio systems have "pinpoint" imaging that can't be heard in real performances in live space, it seems some tv's have now gone into "blacker than black" to create gorgeous picture quality that might not be reality anymore, but still looks great as eye candy.

 

[MikeDuke]

I think I have to agree that video people are more insane then audio pelople. My room is probably far from "ideal” it is a small second floor room with a big window and venetian blinds. I can turn the lights off obviously but it won’t get completely dark until the sun goes all the way down. But we all have limitations and I have delt with them the best I can.
Thanks for the info.

 

[cjfrbw]

Wow, I looked up the Panasonic 42G25, that is a great TV, I can't imagine any complaints. It must look wonderful under any viewing circumstances!

 

[MikeDuke]

No complaints? Now that would be a first. The biggest complaint or worry was the rising black level. Panasonic implemented something in their TV's that was supposed to make them last longer. I guess they felt that they could extend the life of the TV. They messed with the voltage output. Long story short, when the voltage changed the black level rose dramatically. There was tremendous outrage about it. People started to say that their blacks were turning grey. Well, it seems Panasonic got the message. In the newer ones of the line(most of the 2010's), they adjusted how extreme that jump would be. I may have been lucky and gotten one of those. Now besides that people have complained about a hum, I have yet to hear it, and floating blacks, I have only seen that twice. As for me, I truly have no complaints. On Blu ray and standard DVD the picture is really fantastic.

Here is the problem as I see it. I can sum it up in two words. Pioneer Kuro. Those TV's were so good that if what's out there does not at least match the Kuro, people think the TV is no good. The rumor is that next year's models may exceed the old Kuro's. But when you compare something to perfection, it will always fail. I myself have never seen a Kuro so this Panasonic is my reference. Like I said, for me, in my room, it works out very well.

 

[MikeDuke]

I made a mistake in my reporting of my contrast ratio. That's what I get for relying on my 40 year old memory. According to my report, the pre-calibration On\Off Contrast ratio was 7472. Now I don't know what the post ratio was but it was probably still close to that. Do those numbers usually change for the better post calibration? Would a CR that is around 7472 be considered good?

 

[cjfrbw]

I think that is quite good for a flat panel TV for native contrast on-off, the enhancements by electronics etc. would make that much higher for "dynamic" contrast. I went past a TV section yesterday and saw that current LCD panels are getting up to alleged "dynamic" contrast ratios of 30K to 60K, which begin to challenge the "pitch black" discrimination limit of 100K of absolute contrast. I don't know if this is real or some kind of gimmicky specifications war going on. I think my Sony VPL VW200 projector has a panel spec of about 8000, and a "dynamic" spec of 35,000, which would probably measure lower if done by a pro. I have no problem with the blacks of the Sony projector, the picture is beyond wonderful.
However, for projection TV's, you tend to need higher dynamic contrast numbers. My "scratch and dent" 720P Samsung entry level 2009 LCD with a "dynamic" of 8000 looks mighty fine, it doesn't leave me craving darker darks even in low light.
I think there is threshold for black levels, as with audio noise, below which everything is pretty good, but above the threshold, things seem to be worse rapidly in terms of perception.

 

[MikeDuke]

Now I would be remiss if I did not indicate that when I had that test done the room was not %100 dark or pitch black. Either way, whatever it is, the picture looks really good . In a lit room or a pitch dark room at night time.