Plasma: Metodo alternativo per calibrare la luminosità.
Ecco la teoria del utente "redwolf4k" di Avsforum (
http://www.avsforum.com/avs-vb/showt...hp?t=1348641):
"If you have been setting brightness by using, say, DVE BD, going to the pluge pattern and dialing down brightness just to the point when the black background blends with the below black bar, then your brightness is much too high for blu-disc playback. If you have been using this forum's AVS brightness pattern, setting your tv to display bar "17", then your brightness is also too high for video play back. Just because your HDTV's sourceless black doesn't dither, that doesn't mean it is inline with the blu-disc playback video black thats in the actual video. The letterbox bars do not matter.
What baffles me is the misinformation that is flowing through this forum, and all over the internet.
How did this begin?
Take any movie you own that shows video black in a scene. If you have setup your brightness incorrectly as instructed above, you will see a ton of dithering. If the set is dithering, but there is no detail, the brightness is wrong. Want to be sure? Turn your brightness up to 100, see how video black is now gray, with no details?
DVE BD is the best disc to fix your brightness with. Use the grayscale ramp and smooth gradation pattern to set black level up correctly as follows:
See the white dots on the ends of the smooth grayscale patterns? Get up close to the screen. If you have set brightness up incorrectly, as I mentioned above, you will see that dithering continues past the white dot markers, indicating that your black level is set to high. This will be the case if you setup your tv to display the "17" flashing bar, or the 2% above video black in the pluge pattern (depending on the disc you used). Setting your brightness up this way is wrong.
Lower the brightness until the dithering/gradation just begins after the white markers. Those markers exist to show you where video black is. Your brightness is now setup correct.
Return to the movie you tested with to see that your set is displaying video black correctly, without dithering.
This works on all blu-ray discs I have tested. About 10 of them currently.
The big question is why is everyone instructing people to set their brightness way to high to begin with?? I think the trouble lies in people not understanding that (for example) the 2% above black bar in the DVE pluge pattern should be just visible, with your nose up to the tv, not extremely visible, as a 10% above black bar should be.
If any calibrator wants to explain why this is so, please do, as I love a good debate.
Suggest test discs:
Troy Blu-Ray (night scene with brad pit in his tent)
Harry Potter OotP (Harry and friends confront lucius malfoy near end)
Both movies have plenty of video black displayed within the film itself."
In sostanza l'utente dice che il metodo tradizionale per impostare la luminosità (per esempio quello del file AVSHD709) è sbagliato. Infatti, usando questo metodo, viene creato del "dithering" inutile nelle zone nere dell'immagine dove in realtà non ci sono informazioni video.
Quindi propone una soluzione alternativa usando il disco "Digital Video Essentials: HD Basics [Blu-ray]" con il pattern "the grayscale ramp and smooth gradation".
Basta regolare la luminosità usando i 3 puntini bianchi che si trovano alle fine della scala dei grigi (nei quadratati neri). Regolando la luminosità ad un valore troppo elevato si dovrebbe vedere apparire del "dithering" dopo i 3 punti neri (andando verso i neri più intensi), invece con una regolazione corretta il "dithering" si dovrebbe fermare subito dopo i punti bianchi.
Ieri sera, ho fatto la prova sul mio plasma Samsung. Usando questo sistema devo usare un valore di luminosità molto più basso (prima usavo 53 adesso invece 49).
Ho fatto una veloce calibrazione del display dopo avere cambiando la luminosità e devo dire che il risultato non è male. I neri non sono affogati e il dithering e quasi inesistente.
Non sono un esperto e volevo sapere cosa ne pensate!
