- Rep Power
I have a question about a somewhat unexpected behaviour in my TV. It's a fairly old LCD number (a whopping two inches thick, no less, with speakers mounted on the side), 40-odd inches, and labelled 'HD ready'. I have a PS3 connected to it (through a Denon AVR-2310), and whenever I see big solid patches of a single colour, I get the feeling it's... sort of moving. It's really hard to describe accurately, not knowing the lingo, but it's as if seemingly random pixels across the whole panel fluctuate to +/- 7 points on the brightness scale. You'd have to be really close to spot it, and know what you're looking for...
My 'beef' is that I don't get a fully stable image - entirely normal, poor setup, or actual problem? It has been like this ever since I bought it, second hand. I mucked about in the settings and found that reducing contrast (was in the high 90s, now down to 50-60) made this much less noticeable, but it still happens.
Mucking about some more in just about every place other than in the TV, I eventually discovered that the signal that reaches the TV is 1080i, not 1080p. Could this phenomenon be caused by interlacing? It seems like a probable explanation, based on what I've been reading, but it would be nice if someone could lay down the law.
(BTW, it also has a dead pixel. Drat, only 2 million left...)
(I also left out the exact model because I a) don't know what it is, and didn't feel like mounting an exploratory expedition and b) suspect this would occur in every TV that receives 1080i. Kick me if I'm wrong.)
- Rep Power
Actually... After looking some more - literally - the phenomenon is more noticeable where there are many different colours or colour tones. I'm less surprised by that, though. Also, it happens regardless of input source - PS3 (HDMI through Denon AVR-2310) or Blu-ray (HDMI straight from Denon DBT-1713UD and through aforementioned receiver).
I want to emphasise that this is really not a big deal at all, but I'm curious about this. I went into a hifi shop the other day, and none of their (admittedly very recent) stock behaved like this. They can be expected to do full 1080p, though.
Also, the model number: 32PF7331
(What the... I thought it was 42"!? Whatever, with the speakers on the side it's too big either way, where I've placed it at present.)
Hi Silent Warrior,
Apologies for the late reply.
HD Ready means the TV is capable of receving HD signal up to 1080i, so your TV is not capable of displaying any more than that.
Also please describe the way your devices are connected in more detail:
PS3 <-> receivere <-> TV
Which connection is used here for example?
Please try to turn the resolution output of your devices down to see if this resolves it.
- Rep Power
My PS3 is connected by its single HDMI out to the receiver's HDMI in 1 (marked DVD). There the signal is split - audio going out to many many speakers, and video is sent back to the TV by way of the one HDMI out, which is connected to the TV's HDMI in 1.
PS3->AVR2310 - 3rd party, blue colour (connector is marked 'WIRES')
AVR2310->TV - more fancy design with twisting connectors, possibly more recent (no markings, other than 'imported by [chain X]' and some unspecified number)
I have used those cables since day one, basically, though I had to change them around at some point because the picture... failed. Failed terribly. (So I switched the cables around, and now everything's just dandy again? ... Ok. Home electronics, gotta love 'em.)
I have also tried reducing the resolution, but the phenomenon still happened in one game, if subtly different from what I've seen in another game. I need to test this more, though, before any conclusions can be made. I'll see if I can have a report ready by Monday - busy weekend ahead.
There's also a hint of this when I use another device to watch Blu-ray movies, but I can't tell whether it's the same thing, or an intentional background animation...
- Rep Power
Ok, I got to do some testing yesterday. On closer inspection, this only happens on my TV (the newer Samsung TV didn't exhibit this behaviour), and resolution or i/p doesn't affect anything. I could also only really see it on darker colour tones (across the whole panel).
But then I stumbled across a review of a 4K monitor on Sweclockers.com, and spotted this little passage:
Dell avslöjar i alla fall att panelen har ”1.07 Billion colors, 8 Bits + A-FRC ” vilket betyder 10 adresserbara bitar per kanal men att panelen endast kan skapa 8 bitars nyanseringsdjup. Resterande bitar uppnås med tidsstyrt gittermönster (temporal dithering) och detta kallas för A-FRC, Advanced Frame Rate Converter. För att skapa motsvarande 10 bitars nyansering kommer pixlarna, vid behov, att cykliskt skifta läge mellan två positioner.
Detta förekommer på enklare LCD-paneler, särskilt TN-paneler vilka sällan på egen hand kan nyansera djupare är 6 bitar. På dessa paneler är gittermönster väldigt tydliga, som ett halvtonsmönster eller som att det ”brusar” i vissa nyanser, särskilt mörka nyanser.
Inget av detta syns på UP2414Q när vi letar efter fenomenet. Förklaring är dels att dithering och gittermönster blir mycket tydligare när man endast har 6 bitar att utgå ifrån. När det redan finns 8 bitar är man på gränsen för vad ögat kan uppfatta som nyansskillnader. Det är också betydligt svårare att se fenomenet när pixlarna är så pass små som hos UP2414Q.
Well, I suppose it's best to pass that through a Swedish office if you want a thorough translation, but this 'temporal dithering' that can cause some sort of static that is 'most visible in patches with dark colour tones' sounds exactly like what I'm experiencing. (On comparing with that other TV, I suspect I don't get 60 Hz either, but that's a chapter for another day.) I have trouble finding any clear information, but I suspect my TV has a TN-type panel, and makes use of temporal dithering. Meaning this is all part of the design. Can someone verify this?