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Product Review
 

Sanyo PLV-70 Three-Panel 16:9 LCD Digital Multimedia Projector

December, 2002

Steve Smallcombe

 

 

Specifications:


2,200 ANSI Lumens
Wide XGA (1366 x 768) Resolution
True 16:9 Aspect Ratio
900:1 Contrast Ratio
New Color Management System
Network Connectivity (with optional
    Pj-Net Organizer)
3D Digital Noise Reduction
Power Lens Shift (Up/Down)
X-Y Digital Keystone Correction
HDTV Progressive Scan System
Power Zoom/Power Focus
Digital Visual Interface (DVI-D)
Whisper Quiet Fan System (35 dBA)
A Variety of Optional Lenses Available
FCC Class B Rating


MSRP (USD) $8,995 (Available from
ProjectorPeople.Com for $5,399
)

http://www.sanyo.com 

 

Introduction

Although there are a large number of digital projectors on the market, the majority of them are designed for board room presentations rather than home theater. They provide plenty of brightness, but not very good black levels, so they are not suitable for watching movies.

The Sanyo PLV-70 is a Wide (16:9) XGA (1,366 x 768 pixels) Digital Multimedia Projector. It is labeled as a “Multiverse Projector” which implies versatility. While the PLV-70 would not be my first choice to take along on a business trip, because of its size and weight, the PLV-70 is a very nice projector for Home Theater (“HT”) usage.

For the HT enthusiast, the PLV-70 offers features and performance at levels that put this projector in a class of its own. While this may sound trite, the specifications and actual performance demonstrate its truth. The PLV-70 uses three 16x9 LCD panels, with 1366 x 768 resolution that feature a Micro Lens Array (“MLA”). The MLA is supposedly used to direct more light into the individual pixels of the LCD panel. This MLA should lead to higher efficiency (more light per projector bulb watt), perhaps a better contrast ratio, and perhaps even less of the dreaded “screen door effect," the bane of many digital projectors, especially those that use LCD technology. Whether the MLA is responsible or not, the PLV-70 manages to get 2,200 ANSI Lumens out of a 200 watt UHP bulb, which is more than twice as much as some other projectors that use similar 200 watt bulbs. The contrast ratio specification for the PLV-70 is 900:1.

Many HT projectors are rated at 700 to 1,000 ANSI Lumens, and many of these projectors do not achieve their rated Lumens specification when calibrated at D65 (color temperature of 6,500 Kelvins, or 6,500K). The PLV-70, which can achieve 2,200 Lumens when properly calibrated, therefore has the potential to give a much brighter image than can be achieved with any other projector intended for the HT environment. All that brightness may not always be necessary, but as we will see, having lots of Lumens makes this a very versatile projector.

Inputs and Connectivity

The PLV-70 can most likely connect to and easily sync with any input you might give it. Besides the now common composite video, S-Video, and RCA-based component video connections, the PLV-70 has five BNC connectors that can either be configured as a second component input, or as a five wire RGB input (Red, Green, Blue, V-Sync, H-Sync). The PLV-70 also has an analog (VGA) port, and a Digital Visual Input, (“DVI”), which allows connections to DVI-equipped computers and set-top boxes. The DVI input is likely the best available protection against future obsolesce if the industry implements a digital copy protection scheme. I understand, however, that the PLV-70 DVI input is currently not HDCP compliant, although it could potentially be made compliant in the future if Sanyo makes such an upgrade available.



Controls

The top of the PLV-70 has the typical controls plus a few more.

The remote control is well designed and allows easy selection of inputs and video memories (labeled ‘Image’), aspect ratios (‘Screen’), as well as access to the various power functions discussed below. The major keys are illuminated for 10 seconds when a button on the side is pressed. Navigation through menus is accomplished via rocking the big button in the top center or by pressing it to select the desired item. I prefer discrete buttons, as I feel they reduce mistakes (especially when in the service mode), but that is clearly a matter of individual preference.

Power or Motor Driven Features

The last thing that I want to highlight before we look at the actual performance of the PLV-70, is the various power or motor driven features. The PLV-70 has power zoom, power focus, and power lens shift. The power focus is handier than you might think; it allows one to stand near the screen and carefully adjust the focus so as to minimize screen door while maintaining maximum image detail. This really can’t be done while standing at the projector (more about focusing and the MLA later).

Power zoom is always nice, but it is the power lens shift that comes in handy, as it makes installing much easier and more flexible. In the HT environment, people usually try to avoid keystone correction like the plague, as it wastes precious pixels and could be another source of artifacts. This typically means carefully positioning the projector so that the lens height is at the level of the top of the screen for ceiling-mounted projectors, or at the bottom of the screen for floor/table-mounted units. 

Well, in the last few weeks, I have had six projectors that I tested or critically viewed, and for each one, I had to carefully find the right combination of paraphernalia to properly position the height of the projector. This is even more complicated for a projector with a long-throw lens (more telephoto), like the PLV-70, since they will normally be mounted behind the seating area, which in my case includes a centrally positioned couch. Thus with a projector that has a long-throw lens, I would have to place the projector a bit too high, above the couch, and tilt it down, compensating for the resultant keystone with the digital keystone correction in the projector - not ideal, but often necessary. What lens shift does is move the lens up or down, staying flat to the LCD panels, and this moves the image up or down on the screen without having to tilt the projector.

The PLV-70 does have the typical digital keystone correction for vertical displacements, and, as a bonus, digital keystone correction for horizontal displacements as well. The power lens shift, however, totally eliminates the need for careful vertical positioning or keystone correction. One simply places the projector where convenient (vertically), and uses the controls on top of the unit or the remote control to shift the lens up and down, thus properly positioning the image on the screen while keeping it perfectly rectangular.

The range of the lens shift is such that for a ceiling mount, one can place the projector at any height from 8 to 10 inches above the top of the screen, down to the centerline of the screen, and then properly position the image using the lens shift. The situation is similar, but reversed, for a table mount, so I had no problem placing the lens a foot or so above the bottom of the screen. I simply used the power zoom and lens shift functions to fill my 16x9 screen with a perfectly rectangular image. The thought of using the power lens shift in conjunction with a masking system for 2.35 images was very tempting, because it would mean that only a single mask is needed. 

That brings me to the next subject – placement in the room and room size. As mentioned above, the PLV-70 has a long throw lens. To fill my 102-inch screen (16x9 diagonal), the projector must be at least 13 feet from the screen. The heat from the projector exits via a rear vent. The manual recommends either 50 cm or 3 feet of clearance behind the projector to allow for adequate heat dissipation. I’d say that the 3 feet is probably conservative, but the 50 cm or about 20 inches, is not. I spent several warm afternoons and evenings in a closed room with the PLV-70 and it does put out the heat – no doubt about it. The Theta Dreadnaught amplifier wasn’t helping either. 

The point is, that with the standard lens, the PLV-70 needs lots of room to breathe. My projection screen is 2 feet from the front wall. Now add 13 feet to the lens, 17 inches for the projector itself, and another 2 to 3 feet behind the unit for heat dissipation, and the PLV-70 barely fits in my 19-foot long room. 

Given the prodigious amount of light the PLV-70 produces, however, it was remarkably quiet and I watched many an evening's entertainment seated 12 to 18 inches to the side of the unit. The fan noise never really bothered me during programming, although it was clearly evident when the sound was muted. 

Another consideration is that if I were to buy a PLV-70, it would be replacing a projector with a short throw lens, and I already have cables exiting the ceiling over the coffee table in front of the couch. Converting to a long throw projector would be a lot of work. Given all of the above, I would probably install the PLV-70 at the back wall with a hole or vent so that the heat and noise could exit into the neighboring room, reroute cables, patch the ceiling, etc. If you are getting the idea that I did spend a fair amount of time thinking how the PLV-70 would fit into my HT, you are right. I became very fond of it after living with it for a month or so. It was the projector of choice on more evenings than not.

First Impressions

As I first opened the Sanyo box, I was reminded of the PLV-60, Sanyo’s previous offering for this venue. I was a bit skeptical, as I had worked with a number of PLV-60 owners, not only to calibrate their projectors, but also to address some Sanyo Quality Control issues. So, when I first turned on the PLV-70, I studied uniform gray fields and gray ramps to look for tell-tail signs of familiar problems. I was very pleased to see uniform colors and clean ramps without any abnormal steps or lines. There were no dead pixels on my unit, and the convergence was excellent. This particular unit did, however, has a small horizontal red band at the bottom of the screen. While a bit annoying, and clearly something that would need to be fixed by Sanyo, if I were to keep this projector, this issue did not in any way prevent me from enjoying its full potential to make superb images.

Measurements Tweaking and Viewing

User level adjustments

Most users with video projectors at this level of sophistication know that they must use a test disc, such as Avia or Video Essentials, to set brightness and contrast, as well as color, hue, and sharpness. 

The menu system with the PLV-70 is well organized and allows adjustment of the normal items plus color temperature, both through names like ‘low’, ‘mid’ and ‘high’, or via setting levels for the primary colors directly. There also was a welcome gamma control, noise reduction setting, and a unique Color Management System.

Setting the brightness control accurately is essential, as it assures a consistent definition for black between the source and the projector. If the brightness is set too high, then the black level is not as good as it might produce. If brightness is set too low, then parts of the image that are intended to be shadows or details in dark scenes are lost. Setting the brightness accurately can be done either by using the Avia ‘black bars’, or using light meter sensitive to low light levels, and a black screen. With my setup and the mid color temperature, I found that 33 was the optimum brightness value, but this should be carefully adjusted for your particular combination of components.

Setting the contrast is exactly the same thing, but you do it with a white image. Set it too low and you will lose image brightness and contrast ratio. Set it too high and you will lose details in the highlights of the picture. I found the right contrast value with the mid color temperature to be 34 to 35, using the light meter to find the optimum value.

The color and hue controls are concerned with setting up the color decoder. These setting will be discussed in much more detail in the measurements section below.

I lowered the sharpness control to 5 and left it there, as the default setting of 15 was much too high. 

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. If it is not correct, a gray image might be purple in dark areas and orange in bright areas.

Projectors meant for HT usage typically make white by shining just the right proportion of red, green, and blue light on the screen. Ideally, shades of gray should have the same proportion of red, green, and blue as white, but less brightness of each color. What’s important is that this RGB ratio be the ‘corect’ ratio, and that this ratio remains constant as the intensity of the light in the image changes. This ability for the color balance to track properly with the different levels of light intensity is therefore what is called ‘grayscale tracking’. 

Why is this so important? Well, imagine watching a black and white movie on your color projector. Ideally whites should look white, blacks should look black, and all the shades of gray should look gray. If the projector in the darker part of the image uses too much green, the shadows would seem a bit greenish, and that would be distracting. If the highlights look yellow, that would also be distracting. So, it is important that all light intensity levels of ‘gray’ have the same ratio of all three colors to achieve a good black and white image on a color projector. Grayscale tracking is also important with color images, as one does not want the color of an object to change as the level of illumination changes, or is in a shadow. Good grayscale tracking, however, requires careful calibration – typically beyond that done by the manufacturer or easily done by a user without test equipment. 

When testing projectors, I use a system that I developed called “SMART”, which measures the intensity of the three primary colors using test images and shows the results in several types of graphs. In particular, SMART uses the Avia disc to display a series of images in which windows appear in the center of the screen, against a black background, that represent black and white and various shades of gray in linear steps of 10 IRE units. (IRE is term use to represent the video input voltage level with black represented by IRE 0, and white by IRE 100.) With each of these IRE windows, SMART uses a highly sensitive light meter (SMART III) and colored filters to measure the light intensity of each of the primary colors at each IRE level. To learn more about SMART, visit http://www.smartavtweaks.com.



The Light Intensity data from the PLV-70 "out of the box", as a function the video input signal or IRE level, is shown in the chart above. In this case, the color balance was set to "mid" and the gamma to 10. The measured light level at the screen with an IRE 100 window was 76 ft-L, which corresponds to 2,240 Lumens! The measured contrast ratio (IRE 100 window vs. black) was 516:1, somewhat less than the 900:1 specification, but still quite respectable. 

Note that the response function of the projector is not linear, (i.e., the output light level is not linearly proportional to the input level), but follows a curve. This is, in fact, the expected behavior, as we will discuss in more detail below in the section on ‘gamma tracking’.

What we also see in the above graph, are separate traces for red, green, and blue which all rise along pretty much the same curve, although the red curve lies a bit below the others. This indicates that with the mid setting, the color temperature of the projector is a bit above the desired color temperature of 6,500K, i.e., slightly blueish. A custom setting somewhere between "mid" and "low" would likely give a color temperature closer to 6,500K or D65. 

As discussed above, a consistent ratio of colors as a function of IRE level is as important to overall picture quality as having an absolutely correct color temperature. In the color intensity chart above, it is difficult to discern the details of the color balance at the low IRE level, or how the overall color intensity compares to the ideal for that IRE level. For these purposes, SMART uses two different charts: one for color balance and one for gamma tracking.


In a color balance chart generated by SMART, we can compare the ratios of the various colors at the various IRE levels. In this case, the intensity for the individual colors is compared to the average intensity for that IRE level. In the color balance chart, ideally all three curves would stay very close to 1 at all IRE levels, indicating that the color balance was the desired one, and did not change as a function of IRE level. 

As can be seen in the above Color Balance graph, the PLV-70, out of the box, shows reasonably consistent color balance over most of the IRE range. This chart also shows that the color temperature is a bit high using the mid setting, but again that is fairly easily corrected. More problematic is that, at the lowest IRE levels (near black), the color balance swings strongly towards the blue-green (blue and green are at 1.15, while red is at 0.68). When viewing images, this results in a greenish cast to the black or darker parts of the image in darker low contrast scenes. For instance, when displaying the IRE 20 or IRE 30 window, the window itself looked reasonably gray, but the black background had a greenish cast in comparison. This is one of the first issues we will address when we start tweaking the projector.

(Often in reviews, one will see plots of Color Temperature vs. IRE level as a way of showing the quality of a projector's grayscale tracking. Color temperature tells you about the ratio of blue to red in the image. SMART uses a similar display to show the behavior of all three colors.)

Gamma Tracking

The other thing we need to look at in more detail is gamma tracking, or how the light output of the projector responds to the input signal. As mentioned above, the relationship between input signal level and light output is not linear, as one might expect, but follows an exponential function. The exponent of this function is referred to as gamma for the display. If the projector tracks the desired function properly, then the image will appear as the director intended, with shadow details preserved at low IRE levels and highlight detail maintained at the high IRE levels. 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. 

Gamma tracking can be graphed for red, green, and blue separately, or as shown below, for the overall light intensity, where the color intensities of red, green, and blue are combined in a manner similar to how the human eye sees light intensity.

 

In particular, the gamma tracking graph from the PLV-70 shows the ratio of the measured combined light level to a theoretical level calculated, in this case, calculated using a target gamma value of 2.5. If the projector is accurately producing the intended light intensity level as a function of IRE level, the gamma tracking graph will show ratios at all IRE levels that are close to 1.

In the Gamma Tracking graph we can see that the PLV-70, with a user gamma setting of 10, has accurate gamma tracking that is well described, with an overall gamma of 2.5. The gamma tracking chart shows the ratio of measured light intensity at a given IRE level compared to the theoretical value for a given target gamma, 2.5 in this case. If all measured values were at 1 (where 1 represents the target gamma value of 2.5 for this projector), then the projector would have gamma equal to the target or ideal gamma tracking. At the highest IRE levels, there is a little bit of compression that, though not ideal, is not uncommon. Deviations from the theoretical at this level will not cause a significant loss of highlight details. 

Color Decoder Accuracy

At this point, it is very important to understand the difference between grayscale tracking accuracy and color decoder accuracy. As discussed above, grayscale tracking has to do with the proportion of red, green, and blue in black and white and all the shades of gray. If all we watched were black and white (and gray) movies, this would be sufficient. With color images we also care how accurately colors are made. Red is red, of course, but we want to have reds of various levels of saturation or ‘redness’, and we want combinations of the primary colors to make all the other colors in all their various levels of saturation. Making accurate colors is the job of the color decoder. When someone says that a projector has ‘red push’ they mean that red is more saturated in the image than was intended, not that there is too much red in the white and gray parts of the image. These are separate issues and should not be confused.

When we use a blue filter and a color bar test image to set up the color control using a test disc, we are controlling the level of saturation of blue. The Avia disc has another very useful test image called the Color Decoder test in the Special Tests menu that examines the level of saturation for all three primary colors. Hence, the Avia disc comes with a green and red filter to use in this test, as well as the more common blue one. In the Color Decoder test, the appropriate filter is used to check the color decoder accuracy for that primary color. The image contains a gray background and a series of red, green, and blue colored squares of differing levels of saturation. If you had previously set the color control accurately using the color bar test and now use the blue filter to look at the Color Decoder image, you should see that the blue square labeled 0% is about the same level of intensity as the gray background. This would indicate that the color decoder is set up accurately for blue. With an accurate color decoder, one would get a match at 0% for the other two colors as well, using the other two filters and looking at the red and green squares. If, on the other hand, the red square labeled 20% matched the overall intensity of the gray background, then you could conclude that that the projector had 20% red “push”.

With the PLV-70, the color setting using the color bars went to 37 or perhaps higher (32 is the midpoint of the range), and the tint control stayed at 32. These settings did show a good match at 0% for blue as expected with the color decoder test, but red showed matched intensities at about +15%, indicating a red push, and green at –5%, indicating a slight negative green push. Lowering the color control to 35 gave what is probably the best compromise - red was still more saturated than green and blue, but it was not as obvious in non-test images. While most projectors allow service mode tweaking of grayscale tracking, few allow color decoder errors to be fixed.

The PLV-70 has a unique Color Management System that allows a user to select a certain part of the image and then edit that color. I tried this using the Color Decoder Accuracy image by selecting a part of the image with a certain level of saturation, and then asked that it be substituted with a part of the image that showed the correct level of saturation. In principle, this system could be used to correct the color decoder accuracy. However, my attempts to do so on several occasions were not successful. It probably just needs more time and experimentation.

Scaler and Deinterlacer

The PLV-70 has three 16x9 LCD panels, each containing 1366 x 768 pixels, and this pixel grid determines the resolution of the display. Virtually all video input sources, however, have a different resolution than that of the display, and it is the job of a scaler to convert, either via expansion or compression, the input signal to the appropriate resolution ("native resolution") for the display panels. Furthermore, many current sources for video are interlaced, and a deinterlacer is needed to intelligently combine the appropriate fields of the interlaced signal to make complete frames for the inherently progressive LCD display. Combine all this with the need to support different display modes, aspect ratios for 4x3,16x9 and letterboxed images, and you have quite a complex problem.

Not too many years ago, one could have paid far more than the cost of this projector for a scaler and deinterlacer to perform just these tasks. Fortunately today, most of the projectors aimed at the HT market have scalers and deinterlacers built in, and the PLV-70 is no exception - it has a very high quality scaler and deinterlacer.

As described in the viewing section, with DVDs (480i and 480p), and with HDTV (1080i), images are very clean and without noticeable artifacts when viewed via the component inputs. What really surprised me however was how good images looked via the S-Video input (standard definition digital broadcast TV from the DISH 6000). This was a pleasant surprise, because with the previous model, the PLV-60, the quality of the scaler was sometimes a bit of an issue. Given the quality of its scaler, and the ready availability of low-cost progressive scan DVD players, I see no reason to consider
purchasing an outboard scaler for use with the PLV-70. Furthermore, even if you have a DVD player with a progressive output option, it is worth checking the image on the PLV-70 using both the progressive and interlaced modes, to see which deinterlacer, the one in the DVD player or the one in the projector, gives the best looking image. You just might be as surprised as I was.  I did all of my critical viewing using the progressive output of my Denon 1600 DVD player, but given the quality of the deinterlacer in the PLV-70, having a DVD player with a progressive output is probably not critical. On the other hand, it is almost difficult to find a new DVD player that does not have progressive scan output these days.

Needless to say, the PLV-70 has all the necessary aspect ratio modes to support 4x3 images (Normal), Enhanced for 16x9 or Anamorphic (Full), and a (Zoom) mode for letterboxed images. These can be selected (toggled) using the screen button. There are also four video memories where the user can store aspect ratios, contrast and brightness settings, etc. These memories can be easily recalled via specific buttons on the remote.

Video Noise

When viewing the various gray test images, especially the lower IRE window (e.g. IRE 30) there was some low level video noise. The gray areas were generally uniform, but a bit noisy (little speckles of lighter or darker gray dancing in the window). The only time I noticed this noise in real images, however, was in areas of absolutely uniform color, such as the blue logo used by Touchstone Pictures. 

Screen Door Effect and Focusing

As mentioned earlier, the LCD panels on the PLV-70 have a Micro Lens Array (“MLA”) that direct more light into the individual pixels of the LCD panel. There have been suggestions that this MLA may reduce the “screen door effect”. My first viewing experiences with the PLV-70 suggested to me that the screen door effect was in fact more noticeable with the PLV-70 than with my reference projector (a Sony 11HT). It was particularly bad in bright scenes with uniform colors. For example, when Arwen first appears in "Lord of the Rings" (LOTR) riding a white horse, the screen turns a very bright almost blinding white. When Harry Potter enters the courtyard covered with snow with his white owl, and the owl flies off into the white clouded sky, the same thing happens. It was fairly easy to see the screen door effect in these scenes. I wasn’t sure whether this was strictly because the much brighter image made it more obvious, or because it was inherently worse with the PLV-70. I suspect it is just that a much brighter image lets you see the outlines of the individual pixels easier.

For reference, I usually sit 14 feet back from the screen, which puts me at a ratio of 3.35 relative to the height of the screen. To reduce pixel visibility, I had experimented with defocusing my 10HT and 11HT and decided that in general, it was not worth it. I lost detail, especially in High Def images, even though at about the same time I had reduced the screen door. 

In my initial viewings of the PLV-70, I had carefully focused the image standing very close to the screen, using the power focus on the remote control. This makes focusing very convenient and accurate. The exact manner in which you focus the PLV-70 can make a big difference in the screen door effect, and it seems possible to greatly diminish the screen door effect without losing much, if any, resolution. The trick is knowing the right way to focus or, more to the point, what to focus on. When you hit the focus button on the remote, a small white or near-white window appears with the word “focus” in black pixels. If you focus to make the pixels or the “grid” of pixels as sharp as possible, that is exactly what you get, along with a significant screen door effect. Focused this way, the grid looks clearly darker than the pixels themselves. If you try, however, to vary the focus slightly from this point, you will find a place where the grid starts to blur or lose contrast, but the word ‘focus’ is still sharp. Go too far, and the black pixels of the word will start to bleed into the adjacent white pixels. It may take several tries to find the right point, but once there, one has an image with much less screen door and without loss of resolution. This is the way to focus the PLV-70. Don’t think of it as defocusing, think of it as focusing on the right information. The LCD pixels are 3-dimensional structures, with depth, so focusing on their front, middle, or back, makes a difference.

Advanced Tweaking the PLV-70

One of the real advantages of accurately characterizing a projector's performance is that you can then use the same measurement system as a guide for tweaking or improving the projected image. Tweaking typically involves changing various control parameters in the projector, such as those that allow adjustment of drive or gain levels, offsets, and gamma controls for the primary colors. In some projectors, such as the Epson TW-100 (kudos), these controls are readily accessible in the user menu. In other projectors, such as the PLV-70, one needs to use a service mode to access all the necessary controls. 

The other tool that can be used in tweaking projectors is colored filters, such as Color Compensation, (“CC”) filters. CC filters have been used quite successfully to improve the black levels and contrast ratios of other LCD-based projectors that use bulbs that are deficient in red (with brighter bulbs, the filament is hotter, moving it more into the blue and away from red). In these cases, a Red CC filter (e.g., a CC40R) is used in conjunction with increased drive levels for the green and blue LCD panels. This combination of increased drive levels and the filter work together to maintain the proper color balance while improving the black levels and contrast ratio of the projector. You can read more about the theory and practice of using CC filters at http://www.smartavtweaks.com.

The first issue that I wanted to address in tweaking the PLV-70 was the blue-green cast at the lowest IRE levels. Unfortunately, with LCD projectors, the light at IRE 0, or black, is dominated almost entirely from what is called leakage. Leakage is light that leaks through or around the mechanisms that the projector uses to modulate or control the light level for a particular color. With LCD projectors, this is typically light that leaks through the LCD panels, even when they are doing their best to shut off the light to make black. It also can come from stray light that bounces around in the light path. Leakage is typically what limits the contrast ratio on digital projectors, and also what determines the color of black. The nature of leakage light is that, by definition, one cannot use the projector's controls to affect it. If all three light paths are leaking equally, then the leakage light will typically resemble the light of the source or bulb, and the same CC filter that can be used to maximize contrast ratio also corrects the color of black, a win-win situation. 

My expectation with the PLV-70 was that I could add a CC30R filter to correct the color balance at IRE 0, and raise the user level green and blue controls to restore color balance, thus maximizing the contrast ratio, black levels and grayscale tracking. In the end, I got two out of three, but that required service mode adjustments.

After adding the CC filter and quickly adjusting the user level controls to restore the color balance at the mid IRE levels, I did a SMART analysis and got the result shown in the Color Balance graph below.


All three colors were tracking fairly well through the mid IRE levels, but there clearly was too much red at IRE 100. After using the meter to examine the effect of the user level controls at IRE 70 and IRE 100, I pretty quickly came to the conclusion that the user level RGB level controls could be used to adjust the color levels at IRE 50 or 70, but that the PLV-70 had a fairly strong opinion of its white balance, so that the user adjustments were not going to have the desired effect at IRE 100 without overcompensating at the lower IRE levels. Since I did not initially have access to the service mode, I did use the projector in this condition for a week or so. This results, while better than out of the box, were not ideal, and this made me more determined than ever to crack the service mode, and in the end, I was reasonably successful.

Once in the service mode, I was able to find the appropriate controls to affect the color balance at IRE 100, the offset adjustments for each color that allow fine tuning of low level color balance and gamma tracking, and a control that affected the overall gamma tracking for each color. Finding all the appropriate parameters took some time, but the effort was certainly worth it.

After service mode tweaking, the Color Balance became remarkably flat, even down to IRE 0! At this point, if I looked at gray windows, gray ramps or gray steps on the Avia disc, the gray images looked gray as they should, and blacks looked black. With the CC filter in place, and as tweaked, the light level at the screen with an IRE 100 window dropped to 35 ft-L, which is still a very bright image. The contrast ratio after tweaking was 550:1, not as good as I would have hoped for, but very respectable. Ideally one will compensate for the red filter by turning up the green and blue drive levels, but I never found the right way to get enough green and blue light, and in the end, had to turn red down a bit instead to restore the color balance. Perhaps given more time to explore the service menu, I can learn how to correct the grayscale tracking and keep more of the brightness, thus further improving the contrast ratio.


Nevertheless, after service mode tweaking, the overall improvement in picture quality was fairly dramatic, especially for blacks and shadows, and it was time to watch some more movies!

Viewing

I had the PLV-70 for about a month, and more evenings than not, I used it for general viewing of regular and HDTV images from my DISH 6000, as well as a variety of movies on DVD. This allowed me to see the effects of the tweaking on movie images rather than bars of test colors. One of my favorite movies is "The Lord of the Rings, The Fellowship of the Ring" (“LOTR”). Although I find the DVD a bit soft compared to the HD version (DISH PPV), it makes a great test DVD, as it has lots of dark scenes, some brilliantly lighted scenes, and many other simply spectacular images. Furthermore, it’s a great story, and my wife never seems to mind watching it. Other favorite movies we watched include "Galaxy Quest", "Harry Potter", "Star Trek: First Contact", and "The Fifth Element". A new favorite for looking at dark images is "The Count of Monte Cristo", with lots of dark night and dungeon scenes.

Out of the box, no filter and no tweaking, the PLV-70 gives a very bright image on my 102 inch diagonal DaMatte (gain=1) screen. The standard light level for ‘white’ in a movie theater is 12 to 16 ft-L. Direct-view TVs are typically twice that. At 76 ft-L, the PLV-70 is very bright indeed - too bright some would say for viewing in a darkened room. If the contrast ratio were 2000:1, then such a bright image might be great. In this case, with a 516:1 contrast ratio, the black level was at essentially the same light level as somewhere between IRE 20 and 30 on my Sony 11HT projector. At this light level, the eye is still very sensitive to color. If the color of IRE 0 is incorrect, then blacks may not look very black at all. In fact, with the PLV-70, they looked sort of blue-green. This is not a problem in high contrast, well-lighted scenes, where the un-tweaked PLV-70 looks spectacular, but in low contrast dark scenes, the blue-green tinge was quite apparent. It is not that shadow details are lost - they are not if the brightness and gamma adjustments are correct - but I find that one needs to have the a certain level of ‘blackness’ in black for the darker low contrast scenes, or else it becomes distracting and takes you out of the movie. The scene in LOTR where the hobbits first encounter the black riders is a great scene for judging blacks and shadow details, as are the scenes in the mines of Moria. There are more dark scenes in The Count of Monte Cristo than I would care to list where black level is an issue. Frankly, I found the black level of the un-tweaked PLV-70 a bit distracting in such scenes.

Therefore, it didn't take me long to add the CC filter and quickly tweak the user levels to restore the color balance as best I could. This really helped a lot in that it partially corrected the color balance at black and it also brought the overall light level down almost a factor of two. Together, these two effects made watching dark scenes much more satisfying.

Later that evening, we were watching a movie in HD on DISH ("Evolution") with the CC filter in place, and my wife said, "This projector is too bright. Can't you do something about that?" Of course, one could turn down the contrast from its optimum value, but then one would lose contrast ratio - not a good thing. So I quickly added a Neutral Density (“ND”) filter that cut the light level another factor of two. This now brought the light level at IRE 100 down to 18 ft-L, still a bright image, and more like you would see in the theater, and much closer to my reference 11HT. The ND filter also cut the light level at IRE 0 by anther factor of two, which was again much more like my reference projector. 

Over the next few weeks as we watched various movies, I added and removed the ND filter numerous times, as it can be done in a matter of seconds (always keeping the CC filter in place). In general, I preferred the ND filter and the better black level for darker low contrast scenes, which is no big surprise, since we do all of our watching with no ambient light, other than the sconces I use for bias lighting. 

I'll have to admit though, that the more we watched, the more I became aware of the advantages of the brighter image available without the ND filter. An image at 35 ft-L or more looks more real, more three-dimensional. The colors look more vibrant with the brighter image. You see more details in the image.

Once I had finished the service mode tweaking and had the grayscale tracking looking really amazingly flat, the image looked just fine with or without the ND filter, so I left it off and enjoyed the superb, bright, accurate image this projector has to offer. There is no question about it, correcting the color balance at the lowest IRE levels makes the darker scenes seem much more real and satisfying. LOTR really looked great now.

Conclusions

In the last few months, I have had the privilege and pleasure of watching and testing quite a few digital projectors in my HT, including not only the LCD model I own and the PLV-70 currently under review, but LCOS and DLP-based units as well. The bright, sharp image coming from the well-tweaked PLV-70 is as good as I have ever seen.

I really liked the brighter image. When I went back to my 11HT, well, it may have seemed more “film-like”, but as I was quickly learning, film-like may be a euphemism for dull. I immediately turned off the Cinema Black mode on the 11HT to get the maximum light level out of the projector. A week later, Cinema Black was either on or off depending on circumstances – it's quieter, etc, and the difference in brightness is not that much. In either case, it isn’t nearly as bright as the CC filter tweaked PLV-70.

There is also no question that the brighter the image, the more tolerant one is of ambient light; the Sanyo is certainly the champ in this case. For critical viewing, however, I would recommend a darkened room for viewing any front projector, regardless of its brightness, because the screen will reflect the ambient light the same way it reflects the light from the projector.

Out of the box, I’d say The PLV-70 was perhaps a bit too bright, given its real world contrast ratio and grayscale tracking, but that is clearly a matter of opinion. A gray screen, like the Stewart Grayhawk, would certainly help. I would however stay away from any screen above 1.0 gain, using this projector. 

The point is that with 2,200 Lumens (and it really has 2,200 Lumens), the PLV-70 is a very versatile projector. It can be used to fill a very large screen (assuming you had a very large room), or can be tweaked to perfection while still giving an image with a brightness that would put most all other projectors at a similar price to shame. Okay, so maybe I haven’t completely turned from a black level connoisseur to a brightness freak, but I certainly have a more balanced view after experiencing the PLV-70.

Would I recommend the PLV-70? Obviously from my review above, the answer is yes, absolutely, provided your room will handle it. As I mentioned earlier, the PLV-70 comes with a long throw lens, and it needs room to breath. It is one very fine projector with performance and features that really set it apart. The only other issue, is that my unit did have a quality control problem, the slight red band at the bottom of the image, so make sure you work with a vendor who will assure you a projector without any major defects. The PLV-70 also takes a bit of tweaking to get just right, but the results are certainly well worth the effort. 

- Steve Smallcombe -

Reference Equipment:

Denon 1600 DVD player B&K Ref 30 preamplifier
Theta Dreadnaught 5x225 amplifier
Acurus 200x3 amplifier (two channels used for rear speakers)
Adcom Power Center
KimberCable interconnects and speaker wire
DISH 6000 HDTV receiver
Velodyne DF-661 front speakers (modified crossover) - 3
Definitive Technology surround speakers - 4
Velodyne 15" subwoofers - 2
SONY VLP-VW11HT video projector (reference projector, tweaked with CC40R filter)

Related to the article above, we recommend the following:

Primer - TVs
   

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