New developments in video displays are cropping up almost faster than we can keep up with them. Many have been exclusive to flat panel LCD and plasma sets. The once-dominant rear projection models are now relegated to the low end of most manufacturers' lines. Yes, there are RPTVs with dynamic irises, LED backlighting, and creative color adjustments, but these refinements are usually reserved for the few high-end models still on the market.

Panasonic, however, is now the first company to market with a new type of projection lamp for its RPTV sets, called LIFI. This lamp is now used in a new six-model line of popularly priced rear projection LCD sets, three of them 1920x1080, the others 1280x720. The smallest of the 1920x1080 models is our subject here, the PT-50LCZ70 at just $1,699.

Inner Light
Developed by LUXIM, LIFI is short for LIght FIdelity. Unlike the traditional HID (High Intensity Discharge) lamps used in most other rear projection sets and all front projectors, a LIFI lamp has no electrodes to fade or burn out. Therefore, it's claimed, it might well maintain its brightness for the life of the set— possibly never needing replacement. It's also said to be cheaper and easier to implement than the LED backlighting that's being used in a few Samsung sets.

A LIFI lamp is also about 1/8 the size of a conventional projection lamp. This is said to make for faster turn-on time—about 10 seconds. I did not find it to be quite this quick, but more like 20 seconds from a cold turn-on to a full brightness image. Nevertheless, that's significantly better than a conventional projection lamp.

In all other respects the PT-50LCZ70 is a relatively conventional RPTV. There are three HDMI connections (one with L/R inputs for separate audio), two component (Y-Pb-Pr), one PC on a 15-pin, D-Sub (VGA) connector, and an adequate assortment of other inputs and outputs (see "Specifications"). One of the HDMI inputs is on the front panel, as is an SD card slot for viewing your own pictures. The inputs can be renamed from a preset list, and may also be selected directly from the remote control.

The set also has EZ Sync, a Panasonic feature that provides for unified control of a wide variety of HDMI-connected components (with appropriate EZ Sync or a similarly compatible design), along with the set. Most manufacturers provide a similar feature in the latest sets under a variety of names. Whether or not it will work when you mix-and-match brands is something of a shot in the dark. This feature was not tested for this review.

Most of the usual features are here; the only obvious omission is the lack of any PIP or POP options. The set's audio quality is about average, but listenable for the buyer who has yet to discover the advantages of a good outboard sound system

There are five aspect ratio options: 4:3, Zoom, and Full are the usual suspects. Just and H-Fill are horizontal stretchy modes designed to fill the 16:9 screen with 4:3 material. H-Fill is not available with 480i or 480p, and 4:3 is not available with 720p, 1080i, or 1080p—which could be an issue if your set-top box is set to upconvert standard definition programming to any of these formats. In that case, you won't be able to view standard definition program material without stretching, cropping, or both. The solution is to make sure your box can put out the native resolution of the program, and is set to do so.

There are three operating modes: Vivid, Standard, Cinema, and Custom. All of these may be individually adjusted by the user, but only Custom allows separate picture settings for each input.

Apart from the usual Picture (contrast/white level), Brightness (black level), Color, Tint, and Sharpness controls, there are several additional features. The Lamp setting adjusts the luminance of the projection lamp, within a fairly narrow range. Color Temp offers just two settings: Warm and Cool. Color Management is said to "[Enhance] green and blue color reproduction, especially outdoor scenes." It's a fixed On or Off control and offers no individual user adjustments. AI Brightness "controls dark areas without affecting the black level or brightness in the overall picture."

There are also four noise reduction controls (Video NR, 3D Y/C filter, Block NR, and Mosquito NR), a Black Level control (which must be set to "Light" with the video sources I used in order to show below black), and 3:2 pulldown for film-based sources. A color matrix control selects between the SD and HD color matrices, but since it's accessible only for 480p inputs it's of little value.

A so-called Pro Setting menu, accessible only in the Custom mode, offers a range of other controls, including high and low white balance (but only for red and blue), AI brightness, which is said to change the mid-level brightness of the picture (sounds like a gamma adjustment of some sort), and Black extension, designed to adjust the depth of grays and black darker than the median brightness level.

The set will not properly display a 1080p/24 input signal. It will show it, but reduced in size and pushed into the upper left hand corner of the screen.

All the important adjustment and operating controls are accessible through the remote control and the on-screen menus. The remote can control three other components besides the TV. The important buttons are large and easy to find in the dark, which is fortunate since it's not backlit.