Introduction

The Panasonic PT-L500U is relatively low cost video projector intended for use in a Home Theater (HT). The 500U is based on three 16x9 LCD panels and has a native resolution of 720x1280, making it fully capable of displaying High Definition television, as well displaying DVDs and other lower resolution video sources.

When we reviewed the AE300 last year, we were particularly impressed with the lack of Screen Door Effect, (SDE), which, no doubt was a result of Panasonic's use of "Smooth Screen" Technology. Panasonic claims that this proprietary technology "helps minimize the gap between pixels, providing a smooth, film-like image". As SDE has traditionally been one of the major drawbacks associated with LCD-based projectors, advances in this area can potentially make LCD technology acceptable to a wider audience.

When we first saw the 500U in a private suite at CEDIA, it appeared that Panasonic had accomplished a further advance in this important area, and the 500U under review demonstrated this as well. The image created by a 500U in many ways looks smoother than any other LCD projector I have seen, and perhaps DLP-based projectors as well.

Panasonic has used another relatively new approach, lamp intensity modulation, to improve the on/off contrast ratio and black levels of the projected image, the other traditional shortcoming of LCD-based projectors. With intelligent lamp modulation - the AI mode in the 500U - the lamp intensity is modulated in response to changing scenes, i.e., the lamp brightness is reduced for dark scenes and boosted for brighter scenes. If done properly, such a lamp modulation scheme can effectively boost the on/off contrast ratio and provide better black levels in those low contrast dark scenes that can look so washed out with projectors that have poor contrast ratios.

Specifications for the 500U include a contrast ratio of 1300:1 and a light output of 850 lumens. Missing, compared to competitive models, such as the Sanyo Z2, is a mechanical lens shift that makes the projector easier to set up in a wider variety of locations.

Inputs and connectivity

The 500U has what today is typical for lower cost projectors, just enough of the right kind on inputs to do the job. Beside the composite and S-Video inputs, there is one set of component inputs, and an HDCP compliant DVI input.

At one point, I might have been concerned about only a single component input, but with the Advent of DVI, one of each will work just fine for most people. Also included are a VGA RGB connector for use with a (non-DVI compatible) computer as well as a 12V trigger for use with equipment such as an electric screen.

Controls

The lighted remote control is simple with just enough buttons to do the job, like toggling inputs, switching aspect ratios, picture modes, or navigating the on-screen menu system.

When switching inputs, the 500U remembers the settings used the last time that input was active, the way I prefer to use video memories, i.e., totally automatic and without the user even thinking about it.

Focus and zoom are adjustable via rotating rings on the lens.

 

The user menu system on the 500U is logically arranged, with most of the items needed for tweaking falling in the Picture menu.

The 500U has an adjustable Color Temp as well as an Advanced menu where there are gain and bias controls for Red, Green, and Blue, as well as gamma controls. This is a real improvement over the capabilities of the 300U when it comes to tweaking grayscale tracking.

One thing I always appreciate about a menu system is a mode where, as you select a particular item for adjustment, the larger menu disappears and a much smaller display of the single item is placed near the bottom of the screen. This helps you see the effect of the adjustment on the picture, or helps significantly if you want to make measurements during the adjustment process, as I typically do.

The 500U gets this almost right. As soon as you start to tweak a control, the menu changes to the minimal mode, but as soon as you stop tweaking, the larger screen-filling menu reappears far too quickly, seemingly only a second or so after the last button press. It is frustrating when something is almost right, but not quite.

The Options panel handles the typical chores of front/rear and ceiling/floor installations, etc, as well as allowing the user to select High and Low lamp modes, and High and Normal fan modes. The High fan mode is for installations above 1400 meters in altitude – perhaps an essential feature if you own a home in the mountains with a Home Theater. If the High lamp mode is selected in the Options menu, the AI lamp modulation mode in the Picture menu can then be set to one of 3 modes, Off, AI1 (for movies with dark scenes) or AI2 (for general video purposes).

The Picture Mode, a toggle on the remote, can be set to Normal, Dynamic, Cinema 1, Cinema 2, Video and Natural that manual says will reproduce the color from the image faithfully from the image source. Having done this once or twice before, I started with the Natural mode.

Installation and Placement in the Room

The 500U has a short throw lens, i.e., the distance from the screen to the projector needs to be between 1.4 to 1.66 times the screen width. This throw ratio will likely mean that the 500U will need to be placed in the room in front of, or roughly at the same distance as the seating area.

With a short throw lens you will also need to be careful in selecting a projection screen. Screens with significant gain should not be used in order to avoid hot-spotting. If you need to use a screen with significant gain, make sure that the projector is at the far end of its throw ratio.

The lack of lens shift means that you will need to carefully place the 500U vertically to avoid the use of digital keystone correction. It is worthy of note that the proper vertical position is slightly above (table mount) or slightly below (ceiling mount) the bottom or top or the screen, respectively. The necessary vertical offset in my setup was about 3 inches.

I was able to ceiling-mount the 500U in the same location as my reference Sony 11HT, on a high shelf suspended from a portion of the Sony ceiling-mount. (I find this setup much better than a table mount, now that we have dogs in the house!) When I mounted the Sanyo Z2, recently reviewed in this same mount, I was able to use the lens shift to allow the projector to remain on its feet – right side up. With the 500U, I inverted the projector, as one would normally do for a ceiling-mounted projector.

The 500U's specification for noise level is 27 dB with the low lamp setting, and in this mode, the projector was indeed very quiet. In the high mode, it was somewhat noisier, but not objectionably so, although it did have a bit of a whine in the sound, which is unusual for LCD projectors (no color wheel). In the AI mode, the fan noise was somewhat decreased and did vary with the input. I was never that aware of changing fan speeds during normal viewing, but if you connect or disconnect the video input being used, the effect on fan speed is obvious.

Measurements and Viewing

Measurements and viewing were done using a Denon 1600 DVD with progressive and interlaced outputs, a Bravo D1 DVD player set to 720p output through DVI, and a DISH 6000 HDTV receiver.

User Level Adjustments

Using the D1 and DVI input to the 500U, the Black Bars test on Avia indicated the proper brightness level to be –17, and the moving white bars, as well as light meter measurements indicated an optimum contrast setting of +6. Color and Tint are not applicable with the DVI input, but using the component inputs, I found the –7 for Color and –2 for Tint, gave the best blending of the various flashing boxes with the Blue Bars test. Once the Color control was set correctly, the Color Decoder test indicated no significant push of any color – a very good result. The default sharpness setting of 0 seemed fine for DVI, the mode in which I did most of my serious viewing.

Preliminary tests indicated that a Color Temp of –1 was the closest to D65, and so that is the setting I used for my before measurements.

Measurements

When I evaluate a projector, I not only look at images, I measure the color balance of the projector at various light intensity levels and determine the quality of what is called "Grayscale Tracking". The idea is that black, white, and all shades of gray, should have the correct ratio of the three primary colors used in video projection Red, Green, and Blue. You can read more about the testing method in my past projector reviews in Secrets, or at http://www.smartavtweaks.com

The Color Balance data for the 500U with the Color Temp control set to -1 is shown above. Obviously, the measured color balance of the 500U is very close to optimal over most of the IRE range with the Correlated Color Temperature (CCT) very near 6500K. Red rises slightly at IRE 20 - 40 (6000K), and at lowest IRE levels, the color balance swings to the blue and the CCT rises steeply.

The measured IRE 100/IRE 0 contrast ratio was 353:1 and the IRE 100 window produced an image that measured 20.5 ftL at my 102 diagonal unity gain (gain=1) DaMatte screen. This corresponds to 650 lumens light output from the projector. The above measurements were made with the lamp mode in High and with the AI mode off.

With the AI mode on (AI 1), the black levels measured for an IRE 0 window (Black) dropped by an additional 30 percent boosting the effective contrast ratio in the AI mode to 500:1.

With the low-lamp mode, the light output with an IRE 100 window fell to 17.1 ftL (541 Lumens), still a very ideal light level for viewing video in a darkened room. With the Lamp in the Low mode, the AI selection was disabled (off).

Gamma Tracking

Gamma Tracking represents how the light output of the projector responds to the input signal. If the projector's gamma tracking is off, then details in the image will either be lost or the image may look flat and have little contrast. The Gamma Tracking graph shows the combined light intensity at the various IRE levels relative to a theoretical level. If the projector is accurately producing the intended light intensity level as a function of input or IRE level all values should be close to 1 in the gamma tracking graph.

In the Gamma Tracking graph above, we can see that the 500U has accurate gamma tracking that is well described with an overall gamma of 2.2 with only a deviation at the lowest IRE levels. This measurement was made using the Natural gamma setting, and again with AI off.

Advanced User Menu Tweaking

After tweaking the color balance in the Advanced menu, I was able to achieve improved grayscale tracking, as can be seen in the graph above, but still with a swing to the blue at the lowest IRE levels. This actually was not much of a problem in normal viewing, but if I owned this projector, I would, no doubt, try using a yellow filter to improve this area a bit more.
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Scaler and Deinterlacer – the Video Essentials Montage

I checked the performance of the deinterlacer using the montage on the Video Essentials (VE) disc, with the interlaced component output from my Denon 1600 DVD player. The pan back from the building was fine, the leaves showed a bit of twitter (typical), and the waving US flag looked just fine with no sign of jaggies. The pan by the bridges looked solid as well. In general, the progressive and interlaced outputs from the Denon looked very similar. The deinterlacing performance of projectors has certainly improved significantly in the last few years.

Viewing and Comments

Over a fairly short period of time, I had the opportunity to watch both DVDs and High Definition Television with the Panasonic PT-L500U, a Sanyo Z2 (recently reviewed), and my own CC filter tweaked Sony 11HT – all LCD projectors of similar resolution, although the Sony at 1364x768 is has somewhat higher resolution than the other two at 1280x720. It is also worth mentioning that I paid almost three times the current price of either the Z2 or 500U for my 11HT not so many years ago, and yet both of the newer projectors are clearly better in many ways. It is therefore natural that in this review I'll compare the PT-AE500U with the Sanyo Z2 as currently they are two of the hot boxes dominating the low-cost LCD projector market.

The 17 ftL - 20 ftL image produced by the 500U is a bright, involving image that is right at the upper end, or just above, the light levels found in commercial theaters. It is also considerably brighter than my reference projector, or the Z2 tweaked with the CC 20R filter necessary to get good grayscale tracking.

I found that the 500U AI mode for the lamp did help with the black levels and on/off contrast without causing obvious havoc with the image quality. I have talked with other who find lamp modulation distracting, but in the short time I have used it, I found it more useful than distracting. Overall, the contrast ratio of the 500U seemed similar to my tweaked 11HT, but not a good as I measured or experience with the tweaked Z2. This is not an issue for most scenes, but darker scenes can seem a bit washed out.

Compared to the other two projectors, however, the most noticeable difference is in the smoothness of the image as a result of Panasonic's use of Smooth Screen Technology. When I first watched the Dish HD demo channel I noticed the difference right away. Part of the demo loop is "Dish" in white letters on a black background. I have always found it easy to see the grid pattern or the SDE in those white letters, even with DLP-based projectors. With the 500U, the grid pattern was reduced almost to invisibility. The difference from the 11HT and the Z2 was fairly obvious and much appreciated.

When we first saw the 500U at CEDIA, I was very impressed with the Smooth Screen Technology, and Panasonic presented a PowerPoint talk that described the double refractive technology of the crystal device used in the 500U. The pixel structure on the screen at CEDIA looked like each pixel had been split into four sub-pixels and thus the apparent grid was essentially four times smaller. With the 500U under review, sometimes I could see this finer grid, and other times the grid looked to have more typical spacing, but with lighter and thinner gridlines.

Over the next few days, I learned the similarities and differences between smooth and soft when it comes to images. Several times while watching HDTV, the image looked soft or out of focus. Focusing didn't help, but switching channels to a true HD broadcast revealed that the projector was sharp as a tack; it was the programr material that was soft. It seems that soft material, e.g., up-converted sources, combined with SDE may give a false impression of sharpness that disappears when there is not much SDE.

It also seems as if I was more aware of film grain in some scenes with film-based source material being displayed by the 500U than I typically notice with other projectors. Perhaps having a 500U is like having very analytical speakers that reveal all the other problems with your system and/or the source material. While some film and upconverted sources looked soft, true HD sources looked outstanding and very sharp indeed. One example was an HD broadcast on ESPN of the Sharks (Hockey) going down in Flames. No problem with motion artifacts that I could see. The only problem was with the final score!

Perhaps another side of the reducing SDE with the 500U, is that I was more aware of Fixed Panel Noise (FPN) than with previously viewed projectors. FPN arises when different adjacent pixels have different apparent gain or brightness with a uniform input signal. With FPN, an image of uniform brightness can look streaked or dirty, just like having a dirty projection screen. This is most noticeable during pans in which a uniformly colored object moves across the screen. In these cases, a stationary pattern becomes more noticeable. For whatever reason, I was aware of FPN with the 500U, and it is not normally something that bothers me with other projectors, although all projectors have it to a greater or lesser extent.

Color and color saturation on the 500U seemed excellent, and the shift to blue at the lowest IRE levels was not particularly bothersome. Again, if I owned the 500U, I would probably experiment with a yellow filter. There is some brightness to spare, and all the needed controls are in the user menu.

Conclusions

The PT-L500U is a true HD native resolution projector (1280x720) that produces a bright smooth image that makes for a very involving viewing experience. Panasonic should be commended for making significant progress with their Smooth Screen Technology as it significantly improves SDE, one of the main drawbacks to LCD-based projectors. In this respect, the 500U has a significant advantage over its competitors.

Advanced tweaking of the 500U is not really necessary. Out of the box, the 500U gives very acceptable performance. If you want to tweak it, all the necessary controls are there in the user menu. In comparison, the Sanyo Z2 required service mode tweaking and a CC filter to give grayscale tracking of similar quality.

The measured contrast ratio of the 500U was respectable, but not outstanding. In this respect, the tweaked Z2 was better. The 500U also lacks the mechanical lens shift feature found on several of its competitors. However, if you can mount the projector centered horizontally, at either the level of the top or bottom of the screen, then this is not an issue at all. If you need somewhat more flexibility in placing the projector, then the Z2 may be a better choice.

Overall, I very much enjoyed using the PT-L500U. No projector available today is perfect, but you can get very high quality images for not a lot of money, especially compared to just a few years ago. The PT-L500U is an excellent projector with a unique set of features. If these features meet your needs and preferences, then I am sure you will enjoy using the PT-L500U. I certainly did.

 

- Steve Smallcombe -