It's October again. And regular as clockwork, the Harvest moon rises, the fall colors turn, the Yankees lose in the playoffs, and the home theater industry sees an all-new clash of the LCD titans, Panasonic and Sanyo.

This year the head-to-head rivalry is between the Panasonic PT-AX100U and the Sanyo PLV-Z5, both of which are native 1280x720 resolution LCD home theater projectors selling for under $2,000. I have no idea who will win the World Series, but when it comes to home theater projectors, we have no shortage of prognostications.

Calling a clear winner between the AX100 and the Z5 is impossible. Both are outstanding projectors that surpass the performance of previous generation models. Each has performance advantages over the other. We have rated both of them a solid five stars across the board, not because they are perfect, but because they represent state-of-the-art achievements that deliver loads of features and great image quality for projectors in this price class. Which of the two of them may be right for you depends entirely on the type of viewing you do. In a nutshell, if you want or need to do your viewing in some ambient light, the AX100U is the better choice, and for dark theater viewing the PLV-Z5 is the better alternative. Each of them has been reviewed individually. (See the Panasonic AX100U review and the Sanyo PLV-Z5 review.)

Impressions and observations

Panasonic has made a huge splash with the AX100U, primarily on the strength of a large increase in potential lumen output over its predecessor, the PT-AE900. The AX100U is rated at 2000 ANSI lumens, while the AE900 was rated at 1100 AL. The AX100 is designed to operate either in a dark room theater environment or in moderate ambient light, as the user's situation dictates. Since many people don't have the ability or desire to view movies and/or sports and other HDTV programming in a dark room, the AX100's wide range of variable light output provides viewing flexibility that most other home theater projectors do not. In this regard, the AX100 is a dramatic step forward beyond last year's AE900.

In comparison, Sanyo's new PLV-Z5 does not appear at first to be a major step beyond the PLV-Z4 released last fall. The spec sheets taken by themselves indicate modest improvements. In terms of contrast, the Z5 is rated at 10,000:1 compared to 7000:1 for the Z4. And lumen output has been boosted by 10%, with spec ratings going from 1000 ANSI lumens on the Z4 to 1100 AL on the Z5. Unfortunately, brightness and contrast specs often have more of an influence on consumer behavior than they should. So let's focus on some real issues that don't appear on the official spec sheets......

Video Resolution. Both of these projectors have a physical pixel matrix, or native resolution, of 1280x720. However, their ability to resolve fine detail is not identical. The AX100U is able to cleanly resolve more lines of standard definition DVD video resolution, both horizontally and vertically, than is the Z5. In practical terms this means that the AX100U is capable of delivering somewhat more precisely defined image detail in, say, the texture of fabric or blades of grass in a lawn. Advantage: AX100U

Pixelation. The AX100U has Panasonic's proprietary "SmoothScreen Technology" which eliminates visible pixel structure, even when examining the screen from just a few inches. In comparison, when examining the Z5 image close up, you can see distinct pixel structure. On LCD projectors in general this is not as pronounced as it used to be due to the reduction of the interpixel gaps, but it is still there.

How big of a deal is this? If you plan to view a very large image from a close distance, say a 120" diagonal picture from a distance of ten feet, you will see some subtle pixelation in the Z5 image that won't be there on the AX100U. It will be most apparent in white text, rolling credits, and subtitles, and will usually not be noticed in the video image itself. If you move back to a viewing distance of thirteen feet, the pixel structure in the Z5's image pretty much goes away since it is difficult to see details that small from that distance. Personally, the Z5's pixel structure does not bother me at all, but for those who are hypersensitive to pixel structure and who plan to sit close to the screen, the AX100U is better at eliminating this artifact.

Advantage: AX100U

Deinterlacing. The AX100U's deinterlacing is outstanding-as good as it gets on projectors that are even in much higher price ranges. The Z5's deinterlacing is close to outstanding. In side by side tests with deinterlacing test patterns, the AX100 shows a slight advantage. However, though the test patterns reveal an incremental strength on the AX100, this does not translate to any noticeable difference in typical viewing. When watching standard definition movie and video clips, one is very hard pressed to ever detect a deinterlacing artifact on the Z5 that does not appear on the AX100U.

Slight advantage: AX100U

Digital noise. An artifact common to digital projectors is noise. This manifests itself as a shimmering instability in certain elements in a video image, and it can impart a subtle graininess to the image overall. The presence of noise, even when you cannot see it as a discrete artifact, can reduce the apparent sharpness of the image. The Z5 has the lowest noise level of any projector we've ever seen in this price range. In side by side viewing with the AX100U, the Z5's lack of noise becomes a significant attribute.

Advantage: PLV-Z5

Contrast. On paper, the Z5 is rated at 10,000:1 contrast, and the AX100U is rated at 6000:1. And in side by side comparison, the Z5 is indeed visibly higher in contrast. Black levels were about the same, but the Z5 rendered greater tonal range and more brilliant highlights. This gives the Z5's image a slightly better depth, or sense of three-dimensionality. The difference is not dramatic, but it is certainly visible to anyone looking at them side by side.

Advantage: PLV-Z5

Image sharpness. One of the most interesting observations in this shoot-out test was that the Z5 image looks sharper despite the fact that the AX100U is capable of rendering finer detail. How could that be? Well, it appears to us to be a combination of all the factors just discussed. Though the AX100U is not excessively noisy by any means, the noise level is higher than it is on the Z5. This tends to offset its latent advantage in video resolution over the Z5. In addition, the incrementally higher contrast of the Z5 contributes to the impression of a sharper image. Finally, we continue to suspect that the elimination of pixel structure on the AX100U, while in itself a good thing, may have some subtle downside effect on sharpness. Panasonic says that it does not, and indeed the AX100U is noticeably sharper than the previous AE900 that had the same SmoothScreen technology. Yet we continue to wonder about it. But for whatever reasons, the fact is that the Z5 renders an image that is incrementally sharper than the AX100U. (By the way, in our tests we had the sharpness control on the Z5 set to -7, which is its lowest setting, and the transient enhancement-another sharpness control-set to L1, which is the next to lowest setting.)

Advantage: PLV-Z5

So, it all depends on what you want to do with it ...

The big advantage of the Panasonic PT-AX100U over the Sanyo PLV-Z5 is its much higher lumen output potential. You can bump it up to 1400 ANSI lumens or more for a bright image in moderate ambient light for a SuperBowl party. You can set it to Vivid Cinema and get over 800 ANSI lumens, which is enough to successfully fill a very large screen, say 150" diagonal or more, in a dark viewing space. In ambient light, the contrast advantage of the Z5 over the AX100U becomes irrelevant. If you are planning to do a lot of viewing in ambient light, the AX100U is clearly the stronger choice.

On the other hand, if your objective is to obtain maximum image quality in a dark theater environment, the Sanyo PLV-Z5 is the stronger alternative. If we did not need the lumen power of the AX100U, we would definitely choose the PLV-Z5 due to its higher contrast, lower digital noise level, and sharper image. Additional attractions are its lower price and three year warranty coverage-the AX100U comes standard with a one year warranty.