Una lettura critica della recensione di Hdtv Test (1)
Panasonic TX-P42G20 Review
By Vincent Teoh • Monday, 8 March 2010, 10:35 pm GMT
The Panasonic TX-P42G20 is the first of many new exciting HDTVs from various manufacturers to hit our review desk in 2010. On paper, the Panasonic TX-P42G20 offers quite a number of extra features — ranging from integrated Freeview HD tuner and USB-PVR functionality to THX certification and ISFccc controls — over last year’s Viera G10 series, but do these translate into a step up in real-world performance? There’s only one way to find out…
Fino qui tutto bene, metto in evidenza quelle che a mio parere sono le funzionalità più importanti aggiunte da G10 a G20
Design
From afar, the TX-P42G20 looks just like any regular Panasonic plasma television, with its glossy black bezel and a matching swivelling pedestal stand (which is packaged separately inside the shipping box and therefore requires assembly). Upon closer inspection however there are a number of practical improvements.
Effectively measuring only about 5cm in depth and 20kg in weight (without stand), the Panasonic TX-P42G20 is slimmer and lighter than the outgoing G10 series. Under external light its “black” bezel takes on a navy hue, and the gradiated accent along the bottom border becomes more obvious. But perhaps more importantly, we observed slightly less on-screen glare and reflections compared to last year’s G10 and V10 plasmas due to implementation of an improved anti-reflective filter. Although this can make the G20 plasma screen look a little grey when switched off, the good news is that its contrast performance is largely preserved instead of washed out during daytime.
Also, by modifying the panel glass design, Panasonic have eliminated the “double image” phenomenon (multi-layered plasma glass causing “ghost image” — e.g. white text on black background — to be repeated behind the original image when viewed up-close and off-axis) on the TX-P42G20 plasma HDTV.
A quick look around the back of the Panasonic TX-P42G20 revealed no cooling fans nor recessed handgrips, and generally solid build quality.
Sul Design non faccio commenti perchè è quanto di piu soggettivo ci possa essere
Connections
The Panasonic TX-P42G20 has 4 HDMI inputs. Only the “HDMI2″ port has met HDMI 1.4 specification by including an audio return channel (ARC).
Direi bene una connessione con specifiche 1.4 è gia qualcosa in più rispetto a G10
Operation
Just like those found on previous Panasonic HDTVs we’ve reviewed, the user menu on the Panasonic TX-P42G20 features large legible fonts, a clear interface, and highly responsive navigation. There are a couple of small drawbacks though: there’s no numerical indicator for the controls when making adjustments; and there’s no warning message asking you to confirm your action when you click on the [Reset To Default] option, making it extremely easy to accidentally erase your saved settings to factory configuration.
Depending on the input, there are up to 6 global picture presets available: “Dynamic“, “Normal“, “Cinema“, “THX“, “Game” and “Photo“. Engaging the [Advance(isfccc)] option in the [Setup] menu is essential to not only unlock the white balance and gamma controls for these picture presets, but also add 2 valuable [Viewing Mode] presets — named [Professional1] and [Professional2] — to each input.
The aforementioned white balance and gamma controls are housed in the [Picture] > [Advanced Settings] submenu. Under the [Setup] > [Other Settings] submenu, you can find more picture adjustment options like [Intelligent Frame Creation] and [Resolution Enhancer]. The latter is basically an edge enhancement control for SD images.
Unlike the other global picture presets, the settings for the two [Professional] modes can be saved independently per input, and also mapped to any other input via the [Copy Adjustment] option. Furthermore, clicking on [Advanced Settings] in both [Professional] modes would open the door to advanced picture calibration options such as white balance, gamma and a colour management system:
These user-accessible calibration controls have been conspicuously omitted from the UK versions of Panasonic flat-screen televisions for as far as we can remember, so a big thumbs up to Panasonic for finally introducing them on the TX-P42G20… AV enthusiasts who wish to adhere to motion picture standards will definitely be pleased.
Metto in evidenza cio che è davvero migliorato fra il G10 e il G20 ovvero la possibilità tramite OSD di cambiare le impostazioni di colour management in maniera decente, sia chiaro però, l'OSD del G20 rimane ancora lontano dagli standard di Samsung e LG in tema di parametri modificabili per la calibrazione.
Calibration
Greyscale
Out of the box, naturally the [THX] picture preset yielded the greyscale closest to D65 industry standard on the Panasonic TX-P42G20 plasma TV
By adjusting the RGB gain and cutoff controls in the [Advanced Settings] submenu (which is made available by engaging the “Advance(isfccc)” option in the [Setup] menu), we calibrated the Panasonic TX-P42G20’s greyscale in [THX] mode even closer to D65, and reduced delta errors (dEs) to below 4 from 30% stimulus onwards
Fino qui il preset THX sembra lavorare abastanza bene
Unfortunately the resultant overall gamma was nearer to 1.9 than the ideal 2.2 (the gamma curve also adopted an S-shape at the top-end), which meant that pictures would appear slightly overbright and washed out due to a drop in image contrast. To add insult to injury, for some unknown reason the [Gamma] control had no effect in [THX] mode on our Panasonic TX-P42G20 review unit, hence preventing us from bringing gamma closer to 2.2.
E qui casca l'asino, il Gamma totale nella modalità THX è vicino a valori di 1,9 anzichè 2,2... per i non adetti ai lavori una vera schifezza che rende le immagini slavate. Un calibratore professionista se vede una curva gamma di 1,9 rischia l'infarto!.
Vorrei che vi rendeste tutti conto che quasi nessuno di noi calibrerà in maniera professionale il TV del salotto. Ci si affida appunto ai preset THX se la curva gamma dei prest THX è sballata (e quanto lo è!) non avremmo mai un immagine decente sul nostro TV a meno di mettere mani al portafoglio e chiamare un calibratore professionista a casa (200€ almeno). Notate anche la sottile ironia del recensore inglese, io trovo quel "Unfortunately" un capolavoro dell'understatement.
Back to the drawing board then. Knowing that the [Professional] modes offer the most comprehensive set of picture adjustment controls on the Panasonic TX-P42G20 HDTV, we recalibrated from scratch in “Professional1” [Viewing Mode].
With lower delta errors (dEs) across the luminance range, calibrated greyscale in [Professional] mode was even better than what we managed to achieve in [THX] mode. The functioning [Gamma] control in [Professional] mode also allowed us to obtain an excellent overall gamma of 2.21 on the Panasonic TX-P42G20 plasma TV.
Come volevasi dimostrare calibrando il TV si ottengono buoni risultati , migliori del THX mode. Basta solo spendere quei 200€/300€ in più per farselo calibrare a dovere, che volete che sia!
Colour
Even prior to calibration, the [THX] and [Professional] modes on the Panasonic TX-P42G20 exhibited accurate primary and secondary colours when charted on a CIE diagram with reference to HD Rec. 709 specification. Switching to any other [Viewing Mode] resulted in an expanded colour gamut with oversaturated green and red primary colour points.
Activating [Vivid Colour] in the [Picture] menu brought about a small amount of red push and a mild change in cyan hue, so we left it turned off (the option is not available in the [THX] and [Professional] modes anyway).
The colour management system (CMS) hidden in the [Professional] modes on the Panasonic TX-P42G20 works quite well, but suffers from the following limitations:
* It is effectively a 2D CMS (i.e. it allows you to adjust hue and saturation but not brightness); and
* You can only adjust the primary colours (red, green, blue) but not the secondaries (yellow, cyan, magenta).
Here’s what we found: when we used the CMS to map the RGB coordinates exactly to Rec.709 specification, a secondary colour would be “dragged” away from its original correct position, or the colour decoding would be off (however slight). In the end we simply left the CMS untouched, as the eventual colour points and colour decoding were accurate enough after calibrating greyscale to D65 in “Professional1”
Per quello che riguarda i colori THX fa un buon lavoro, si potrebbe fare meglio ma è molto difficile perchè come precedentemente detto L'OSD non permette ancora di settare in maniera sufficente i relativi parametri
E' ovvio che non ci troviamo davanti alla tv perfetta, però se la si inserisce nel contesto di ciò che troviamo in vendita nei negozi, siamo senza dubbio davanti ad un'ottima tv, sicuramente una delle migliori.