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Panasonic 50PV700 (TH-50PX700U) 50" 1080p Plasma TV

Part II

September, 2007

Ofer LaOr

 

Panasonic is a tough company it takes them a long time to adopt things like native rate support. 24fps is a must these days, and this new series supports it like a champ. However, native rate support (at 60 Hz and 50 Hz) via HDMI is still MIA.

The contrast ratio of 10,000:1 is a tough nut to crack. Many companies use this number, but in reality no one really comes close. The number is a figment of optimistic projectionism on part of overeager number crunching advertising executives. The number meshes both static (ANSI) contrast ratios with dynamic contrast ratios achieved by contrast stretching and various other nifty techniques. The actual panel contrast ratio is roughly 2000:1, which means that even with a typical 200-250% dynamic contrast ratio, the actual contrast ratio for this display is realistically more like 5000:1 at most. But, 5000:1 is not bad at all.

Interestingly, all of the new panels by Panasonic and other companies are limited by the brightness (dividend side of the division formula). That means companies are likely solving the blackness problem (reaching deep blacks on thin panels is a key problem) by inserting a dark filter which reduces the amount of light on both bright and dark images. Another likely explanation is that the longer life spans (between 60,000 and 100,000 hours to half brightness) are achieved by close monitoring of the panel brightness and by preventing the display from reaching high brightness and burning itself out quicker.

Fill ratios on this panel are much better than previous models, but the fact is that this plasma requires some distance for proper viewing (12 or so feet would be ideal).

The Viera series, in contrast with Panasonic's professional models (PHD10) suffer from a lack of calibration modes and options. When selecting "Color Management OFF", the unit actually refers to a normal color gamut, while the ON mode extends the color gamut by a small amount. In both conditions, the gamut is quite far from the REC601 and REC709 specs.

 

"Color Management" Off "Color Management" On

The display lacks any gamma controls, so in a paraphrase of Heny Ford's famous saying: you can have any gamma you want as long as it's 1.92. Unfortunately, this number is quite low and although it reveals quite a lot of detail, it does leave a milky and unstriking image that could have been enhanced by a more striking gamma curve.

Looking at the PV700's spectral graph, it has a virtually identical signature to Panasonic's older models. This means that the phosphor makeup of this model is the same, and that the improvements in the new generation are mostly in how the plasma cells are structured.

Calibration wise, this display came almost pre-calibrated, with an average 5% mismatch for D65 calibration. This is quite impressive for a display not necessarily intended for pro-sumers, but for popular use.

As I mentioned before, the display lacks any native rate support for its HDMI inputs, which is unfortunate for users wanting to add an external scaler or hook up an HTPC to the unit.

The various formats worked perfectly, including 1080p at 24 fps. All ATSC formats worked out of the box using both 60 Hz (US) and 50 Hz (Europe) frequencies.

A blaring omission for the European market is the missing SCART (a popular European connector).

Go to Part III.

Copyright 2007 Secrets of Home Theater & High Fidelity

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