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发表于 2005-12-2 09:23
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PRODUCT REVIEW: SANYO PLV-Z3 FRONT LCD PROJECTOR
Peter Putman, CTS, ISF
Sanyo’s PLV-Z3 front LCD projector is the third evolution of a series of widescreen, value-priced designs that are successfully holding market share against more costly single-chip DLP designs. It offers native HD (1280x720) resolution and such useful features as horizontal and mechanical lens shift, an HDMI connector, and (in a new twist) a small compressed-air bulb for cleaning dust out of the optical assembly.
Figure 1. Sanyo’s PLV-Z3 with lens cover down.
The PLV-Z3 and other products in its category (including Panasonic’s PT-AE700U) employ three-panel imaging systems as opposed to the single chip and color wheel found in front DLP projectors. The advantage of this system is the absence of visual strobing or flicker artifacts from the color wheel, not to mention a pretty quiet projector – only the cooling fan makes much noise.
The disadvantages of LCD are well known and include higher black levels than DLP, lower contrast, and the ‘screen door’ effect. This latter phenomenon is caused by the distinct pixel edges on each LCD panel and can be distracting with lower-resolution imaging panels.
Not too long ago, many journalists (including myself) had pretty much written off LCD technology as being competitive against DLP and LCoS projectors. However, to paraphrase from Monty Python and the Holy Grail, it appears LCD technology is “not quite dead yet”.
Both Sony and Panasonic have made strides recently in minimizing the ‘screen door’ artifacts on their LCD projectors and boosting contrast while lowering black levels. In Panasonic’s case, the use of a variable lens iris and light sensors has allowed their PT-AE700U to achieve average contrast readings approaching 300:1 and peak readings well over 800:1.
While the PLV-Z3 also uses a variable lens iris, it’s not fully automatic. Rather, Sanyo has tied iris settings to combinations of picture gamma and white balance to create several different image-viewing modes. You can also adjust the iris settings manually. These features, plus lots of other user adjustments, make the PLV-Z3 worth a look.
OUT OF THE BOX
Like its predecessor, the PLV-Z3 retains a sleek flip-down front lens cover. It has to be lowered for the power to come on and for any lens adjustments to be made (zoom, focus, horizontal and vertical lens shift). Two serrated thumbwheels control the lens shift function, which lets you offset the image a total of two screen heights and a full screen width. The lens itself has a relatively short zoom range of 1.3:1.
Figure 2. Two thumbwheels control the mechanical lens shift.
The rear-panel connector complement has been expanded from the PLV-Z2. In addition to single composite and S-video connectors, two sets of component YPbPr inputs are now available. A 15-pin RGB jack, also missing from the Z2, has been added and the remaining connector is an HDMI interface for set-top receivers and DVD players.
Because there are no internal speakers, no audio inputs or outputs are included with this projector. You won’t find a 12V screen trigger, either. One additional DIN-style jack is labeled ‘service port’, but no information was provided as to its function. The lack of an RS-232C port and a screen trigger suggest Sanyo views this projector as a ‘coffee table’ design for more informal viewing.
Figure 3. The connector panel is missing a screen trigger and RS-232 connection.
The supplied remote control is a new design for Sanyo and features large, backlit, and easy-to-locate buttons with bold text. You’ll have direct access to any of the six video inputs, as well as four user image presets and a variety of factory-defined image presets. The largest buttons are reserved for MENU, SCREEN (aspect ratio) and IMAGE (direct access to picture settings) functions.
Figure 4. The supplied remote is easy to navigate and operate.
The small bulb that comes with the PLV-Z3 is bound to raise a few eyebrows. It resembles an ear syringe and is used to clear dust from the three imaging panels. Dust accumulation has long been a problem with LCD projectors, but this is the first time I’ve seen a manufacturer let the customer do anything about it. By inserting the bulb into any of three small holes on the bottom of the projector, you should be able to clear most dust particles in short order.
MENUS
Sanyo has added a lot of functions to the menu from the older Z2 model. In addition to the standard image adjustments (which include a multi-step gamma control and ‘global’ red, green, and blue drive adjustments), you can now adjust RGB gain, RGB offset, and RGB gamma for each of the four user memories.
The factory image presets vary depending on whether you are using the video or PC inputs and include VIDEO, NATURAL, NORMAL, CREATIVE CINEMA, PURE CINEMA, DYNAMIC, POWERFUL, and GRAPHIC. These setting immediately beg questions such as “what’s the difference between ‘powerful’ and dynamic’? and ‘why is there a difference between ‘natural’ and ‘normal’?
These presets make extensive use of the variable lens iris, gamma, and white balance adjustments. You’ll find that the two cinema modes decrease brightness and black levels to make images appear to have more contrast and depth, not to mention warm color temperatures.
The POWERFUL and DYNAMIC modes aren’t recommended for home theater use as they are intended for full light output with no color correction. You’d probably use them to make a business graphics presentation under normal room lighting. NATURAL and NORMAL vary mostly in the selection of picture gamma.
Of course, there is a USER picture mode that is activated any time you start making changes to a factory preset. Four user-defined image parameter combinations can be saved and applied to any of the six inputs. In this menu, you can play with the iris settings, activate a black stretch function and also set three levels of contrast enhancement.
The usual range of picture aspect ratios and scaling modes are included for anamorphic stretch, closed captions, and letterboxed 4:3 sources. If you are really into nit picking, there’s even an OVERSCAN adjustment so you can map a 1280x720 HD signal pixel-by-pixel, leaving thin black lines at the top and bottom of the image.
With all that functionality, I find it odd that Sanyo still didn’t provide the extra connector interfaces for a fully automated home theater installation. Given that competitive models in this price range (like the afore-mentioned Panasonic AE700U) do provide screen triggers and RS-232 control interfaces, this will give some would-be customers pause before buying.
CALIBRATION AND PERFORMANCE
You can kill a lot of time playing with all of those image adjustments, tweaking and tuning here and there to get the cleanest grayscale and best white balance. At some point, though, you will realize a couple of things about the PLV-Z3: (1) it really does have excellent color and good contrast (the best of any Sanyo HT projector I’ve ever tested). (2) However, it still comes up a hair short to some DLP projectors out there in both categories.
The PLV-Z3 can make some really nice pictures if you are willing to spend a few hours setting it up. None of the factory presets really gave me a close grayscale track except for LOW 1, which still ran a bit higher than desired. I set up my own file and was able to get a very clean track from 30 IRE all the way to 100 IRE, with only a bluish shift below 30 IRE skewing the grayscale.
You’ll see that blue WB shift with low luminance levels – amber yellows and subtle green shades will be touch to render correctly, as will flesh tones under low lighting. The problem isn’t as apparent with brightly lit scenes or saturated colors.
There’s plenty of light from this projector. In NORMAL mode, I measured 452 ANSI lumens with ANSI (average) contrast at 269:1 and peak contrast at 462:1, using a checkerboard pattern. With a 50-50 black and white test pattern, the highest contrast reading was 695:1.
Playing with the iris settings and factory presets caused measured brightness to range from a low of 236 ANSI lumens to well over 600 lumens in DYNAMIC and POWERFUL modes. Brightness uniformity across the 16:9 image clocked in at 73%, which is average for an LCD projector.
Starting with composite video, I found some problems decoding the Video Essentials Zone Plate sequence. Color moiré was in abundance and picture detail was missing at 300 and 400 lines. However, the later flag-waving sequence looked remarkably clean, as did the rotating bar and flag sequences on the Silicon Optix reference DVD.
The PLV-Z3 is a little slow to pick up on 3:2 sequencing, as evidenced by the Super Speedway test sequence from Silicon Optix’s DVD. For that reason, I suggest using a good progressive-scan DVD player and/or video scaler with this projector to handle all of the decoding and de-interlacing outboard.
The open illegal immigrant sequence and climactic battle scenes from Men In Black showed that, although the PLV-Z3 can pull deeper black levels than its predecessors, it still drops a fair amount of shadow detail. However, the subtle color shades found outside the stores and restaurants during the nighttime street scenes were surprisingly close to my reference monitor.
The PLV-Z3 suffers (like most home theater projectors) from restricted bandwidth through its component inputs. Using my AccuPel test pattern generator, I saw significant roll-off above 18 MHz using a multiburst luminance test pattern at both 720p and 1080i output rates. Using the RGB input cleaned up this problem somewhat with 720p material only, so hook your video scaler up to that input or the HDMI connector.
Even with the limited bandwidth, both live and filmed HD content really shined on this projector. I watched a Peter Gabriel concert on INHD (shot live in 1080i/30) and was surprised again at how well the PLV-Z3 reproduced the emerald green, light purple, pink, and pale blue lighting effects when compared to my reference monitor.
At one point during the concert, Gabriel rolled around the circular stage in a giant inflatable clear ball with dozens of fiber optic light sources on its edges. This sequence also rendered cleanly with little visible color tinting. But Gabriel himself was dressed in black and much of the detail in his clothing simply vanished at times when he stepped into shadows.
Daytime HD footage from Fox 720p and CBS 1080i NFL games that I recorded to D-VHS held up much better. Colors were saturated, images were crisp and clean, and the extreme grayscales caused by shooting video outdoors on bright, sunny days didn’t cause much of a problem for the projector.
In fact, this projector looks great with 720p live sports, which I confirmed with other D-VHS recordings of hickey, basketball, and Monday Night Football from ABC. If you are a sports addict and can provide that HDMI or DVI connection from your cable, satellite, or terrestrial set-top box to the PLV-Z3, you will be in hog heaven.
CONCLUSIONS
The PLV-Z3 is truly a mixed bag of performance and features. It needs better bandwidth for HD signals, but offers nice color reproduction. It should have a screen trigger and RS-232C control, but doesn’t lack for ISF-level image adjustment options. It has a wide range of mechanical lens offsets, but needs a longer zoom ratio.
After all is said and done, the price will probably be the determining factor. At $2,495 list (with ESPs under $2,000), you might just decided you can live with its flaws and put the money you save over a more expensive DLP projector into better speakers, a new DVD player, or even a video scaler. Sanyo is probably guessing the same thing. |
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