Editor's Note: Given the ongoing debate about the effectiveness of pixel-shifting in 4K and 4K-compliant home theater projectors, our contributor and imaging tech expert Michael McNamara, the principal at In-Depth Focus Labs in Hopewell Junction, NY, experimented with six popular projectors at varying price points. In Part 1, found here, he explains the different factors which can affect perceived resolution and describes in detail how he conducted his tests. Here in Part 2, he shares the photographic results and some concluding comments.—Rob Sabin
JVC DLA-NX7/DLA-RS2000 ($8,999): This projector is sold under two model numbers through JVC's consumer and professional distribution channels. It is the only model in this comparison with native 4K (4086 x 2160) imagers that require no pixel-shifting, specifically three 0.69-inch (4096 x 2160 pixels) D-ILA LCoS chips. It's also the only one that actually displayed full UHD resolution on the test target in both the vertical and horizontal planes. Other key features include 1,900 lumens output, 80,000:1 contrast, and a premium quality 17-element glass 2x zoom lens with motorized zoom and focus. We measured high brightness uniformity in our tests. The projector can reproduce over 100% of the DCI-P3 wide gamut color space, and is HDR10 compatible with Auto Tone-Mapping. (Full review here.)
Resolution Test Target: Natural Mode, Default settings
JVC DLA-NX7 Results: The native 4K imaging devices of this projector, combined with the best contrast seen in the test target among any of the projectors, produced the highest resolution results in the test. The line ladders are clearly discernible (B and D) and crosshatch lines are fairly close in detail (although in this mode they have a slight blueish tint). Upon close inspection all four of the smallest black hash marks between the longer tick marks can be discerned on the vertical resolution scale (A), as well as on the horizontal res scale (C). Therefore, the tested resolution meets the requirements for a true 4K UHD image, with contrast that makes text and line details very readable. (Note: Extreme closeups of the horizontal scale results for all the projectors are found in the Conclusion for comparison.)
Real Image Comparison: Natural Mode, Default settings
JVC DLA-NX7 Results: Color saturation appears to be a bit lower than found in the original target image, with a cool color cast. Shadow and midtone details are very visible, while highlights (scales on arm, E) don't stand out as much, possibly due to lower contrast. Color saturation is also slightly lower, but tonal gradations on the leaves in the background are very visible.
BenQ HT9060 ($8,999): The premium-priced BenQ HT9060 1-chip DLP projector utilizes the larger 0.66-inch DMD containing 2716 x 1528 mirrors, and two-phase XPR pixel-shifting technology. Its features include a long life Philips ColorSpark HLD LED light engine that provides an unusually high (for an LED projector) 2,200 ANSI lumens, a high quality 14-element glass lens with manual focus and zoom, over 90% brightness uniformity, and high color accuracy. It's also HDR10-capable, and covers up to 98% of the DCI-P3 wide-gamut color space. (Full review here.)
Resolution Test Target: Cinema Mode, Normal Power
BenQ HT9060 Results: The BenQ's lower contrast is the most noticeable difference between it and the other tested projectors from Epson and JVC. As noted in Part 1, contrast, or the lack of it, can have a noticeable effect on perceived resolution. On closer inspection, the BenQ's vertical res scale (top target A) barely shows separation between the four fine black lines located between each 10-line indicator—and skips some of the lines in the vertical line ladder (B), therefore its measured vertical res is slightly below the claimed 2160 pixels. However, those line ladders are still visible—which is not the case with most of the other pixel-shifting models tested here. Horizontal res is higher, with lower contrast than desired, but there is visible separation between the smallest lines (C) and in the line ladder (D), so this model meets the claimed 3840 pixels in this direction.
Real Image Comparison: Cinema Mode, Normal Power
BenQ HT9060 Results: This projector does a very good job of reproducing detail in most parts of the continuous tone Mantis photograph, but lower contrast and color saturation produces fewer details in fine color gradations between some similar-tone details like the white arm spikes and background leaves (E).
Optoma UHD60 ($1,799): This model uses a 1-chip 0.66-inch DMD containing 2716 x 1528 mirrors and 2-phase pixel shifting, and also claims to achieve full 4K UHD (3840 x 2160 pixel) resolution. It features 3,000 ANSI lumens brightness, HDR10 compatibility, and up to 100% coverage of the Rec.709 color gamut. Its 1.6x manual zoom and focus lens is sharp, but by ProjectorCentral measurements delivers 64% uniformity at the wide angle end. (Full review here.)
Resolution Test Target: Cinema Mode, Default settings
Optoma UHD60 Results: This model shows slightly lower contrast than the Epson or JVC 1080p pixel-shifting models in this comparison, but higher measurable resolution. However, in both of the fine line ladders (B and D) it appears that only half the lines are reproduced, while the crosshatch lines are also missing fine details. Upon closer inspection you can see some separation between the finest black lines on the vertical resolution scale (A), but certainly not all four that reside between the longer mid-sized hash marks. The horizontal res scale (C) does show all four fine lines, albeit at much lower contrast than found in the native 4K JVC. Therefore, tested resolution in the horizontal direction is enough to meet the claimed UHD resolution, but the vertical resolution doesn't appear to in this specific display mode and location on the target.
Real Image Comparison: Cinema Mode, Default Settings
Optoma UHD60 Results: Overall contrast is decent, and there are plenty of details in the midtone, shadow and highlight regions. Color saturation is a bit high in bright green edges of the leaf in the background, but overall color accuracy is high. Up close, there are some minor noise issues in fine color gradations (E), and some edge artifacts show up around the mantis arm teeth.
ViewSonic X10-4K ($1,499): This compact and portable DLP projector utilizes a 1-chip 0.47-inch DMD containing 1920 x 1080 mirrors and 4-phase pixel shifting to achieve a claimed 3840 x 2160 pixel resolution on screen. It features a relatively small, fixed short-throw lens and a long-life LED light engine and claims to provide 2,400 LED lumens (we tested only 761 ANSI lumens in Brightest Mode—which is half the luminance of the BenQ HT9060, the other LED model in this test). It provides up to 125% of the Rec.709 color space and HDR10 compatibility. (Full review here.)
Resolution Test Target: Brightest Mode, High Power Setting
ViewSonic X10-4K Results: Besides its lower maximum luminance output, the X10-4K produces an image with lower contrast than the others in this comparison. This lower contrast is the reason why the details in the fine line ladder (B and D) are nearly imperceptible unless greatly magnified, and certainly not visible at normal viewing distances. The crosshatch lines are also unusual, so fine diagonal details in any image are going to look strange. Lower contrast text and larger black lines are also harder to see. Upon close inspection there is minimal separation in the finest lines on the vertical res scale (A)—perhaps 3 of 4, while the horizontal res scale (C) shows separation of all 4 but at such low contrast they blur together. Therefore, the tested resolution falls short of a true 4K UHD image, but somewhat higher than found in the 1080p Epson or JVC—albeit with lower contrast. Keep in mind when comparing this with the other DLPs in our test that it not only uses the smaller, four-phase 0.47-inch imaging chip, but also uses a much smaller fixed lens to accommodate the projector's portable form factor.
Real Image Comparison: Brightness Mode, High Power Setting
ViewSonic X10-4K Results: The narrow dynamic range in this model's reproduction is the most noticeable difference from a normal viewing distance. Note how the darker area on the under-arm obscures details and tones that should be lighter, while details in the bright leaves in the background are blown out (E). Greens are also oversaturated, while yellows and light reds (in arm) are undersaturated. In addition, the darker green tones in the background show high amounts of noise, not seen in any of the other models tested.
Epson Home Cinema HC5050UBe ($3,299): This wireless HDMI version of the Epson HC5050UB ($2,999) utilizes three 0.74-inch, native 1080p LCD panels (RGB) and two-phase pixel-shifting to deliver 4K enhanced resolution (4Ke). It delivers 2,500 ANSI lumens brightness, and over 1,000:1 ANSI contrast (tested). Other top features include high brightness uniformity, over 100% coverage of the DCI-P3 color gamut, and a high quality, 16-element, 2.1X glass lens with motorized zoom and focus. (Full review here.)
Resolution Test Target: Cinema Mode, High Power Setting
Epson HC5050UBe Results: The most obvious differences between the original file and the HC5050UBe's reproduction can be seen in the center areas to the sides of the horizontal and vertical number scales. These are missing the fine line ladder (B and D) and produce thicker diagonal crosshatch lines. However, overall contrast is higher than on the BenQ, Optoma, and ViewSonic models, with text more readable and larger black lines popping out, so image sharpness appears higher from normal viewing distances than the scales suggest. Upon closer inspection, only two of the four smallest black lines between the hatch marks can be discerned on the vertical res scale (A), or on the horizontal res scale (C). Therefore, the tested resolution falls somewhere in the middle between what you'd find in a 1080p image and a true 4K UHD image, with a boost in perceivable sharpness from higher contrast.
Real Image Comparison: Cinema Mode, High Power Setting
Epson HC5050UBe Results: Higher contrast contributes to an increase in midtone, shadow and highlight details visible in the Mantis arm teeth (E). Although a bit warmer in color temperature, the saturated colors and fine tonal gradations also improve the impact and perceived separation (3D effect) between the arms and background.
JVC DLA-X790R/DLA-RS540 ($3,999): As with the DLA-NX7, this home cinema model is also sold under an alternate model number, the DLA-RS540, for distribution through integrators. It was previously announced as discontinued, but JVC now says it will remain in production and available through September 2020. It is the last remaining native 1080p D-ILA projector in the company's home theater line-up, and utilizes three 0.7-inch, LCoS D-ILA chips and JVC's e-shift5 technology (two-phase shifting) to project 4K UHD content on screen, along with offering 1,900 lumens and a high native contrast ratio. It also features a high quality, multi-element 2x glass lens with motorized zoom and focus, full Rec.709 coverage, and is THX-certified. (Product information here.)
Resolution Test Target: Natural Mode, Default settings
JVC DLA-X790R Results: Like the other pixel shifting models, the most obvious differences between the original file and the X790's reproduction are the missing details in the fine line ladders (B and D), which in this case also took on different color casts. The crosshatch lines were also jagged, with missing fine line details. While the overall contrast is higher than in several other models in this test, making solid lines jump out, some artifacts can be found in the numbers that make them less readable, and small lines are thicker than they should be. Upon closer inspection, neither the vertical res scale (A), or the horizontal res scale (C) show clear separation in the finest lines, so as with the Epson, the tested resolution falls somewhere in the middle between what you'd find in a 1080p image and a true 4K UHD image.
Real Image Comparison: Natural Mode, Default settings
JVC DLA-X790R Results: The image reproduced by this model shows good contrast and decent color saturation, with darker greens. Shadow and midtone details are very visible, while highlights (E) have slightly lower details. Dark tonal gradations on the leaves in the background show minor signs of banding.
The best resolution comparison photos for this test were taken by the camera closest to the screen on the right focused on the target's horizontal resolution scale. The six closeups shown side by side below show the exact same section down to the pixel level.
The clear winner among these projectors, with the highest resolution and detail, very good contrast, and very readable text is the JVC DLA-NX7, the only projector in this test containing three true native 4K resolution imaging devices (and requiring no pixel shifting). Even at the relatively small image size in the composite, you can clearly see the NX-7's four fine black lines in between the longer hash marks. (See arrow, A). These lines correspond to 3840 pixels of resolution from the left side of the image to the right side.
Of the pixel-shifting DLP models, the BenQ HT9060 showed the highest horizontal resolution, with all four fine tick lines between the hash marks visible (B). Text is well formed and readable, although lower contrast than in the JVC DLA-NX7, Epson HC5050UBe, or Optoma UHD60. The Optoma takes third place in overall detail, with most of the fine lines visible (some are blurred together), well formed text, and slightly low contrast. Its pixel structure is also slightly visible (C), as it is on the Epson HC5050Ube, but in neither case could the pixel structure be seen at normal viewing distances.
The Epson HC5050UBe (D) takes fourth place even though it only shows separation between two of the four super-fine lines and no line ladders in the horizontal direction.. However, its higher contrast and darker lines improve perceived sharpness and text at normal viewing distance. In fifth place, the JVC DLA-x790 (three-chip, native 1080p with pixel shifting) shows one or two of the four super-fine lines and none of the line ladders as found on its 4K native sibling, the DLA-NX7. It also had the worst font production of all (E). However, its contrast is better than any of the DLP models, and as found with the Epson, that improves perceived detail at normal distances.
The ViewSonic X10-4K has the lowest resolution of all the DLP models, as well as the lowest contrast and luminance of any model in the test. As mentioned earlier, this is the only DLP to use the smaller 0.47-inch DLP XPR imaging device with four-phase pixel-shifting. As a portable lifestyle projector, it's also the only model here not to feature the optics of a traditional long-throw home theater lens. Some combination of these differences came to bear in its test targets, which barely show any discernible fine lines (F). They are there, but at such low contrast they tend to merge into the background instead of forming a darker line from a few feet away. Vertical resolution was even lower on the target—and does not reach the claimed 2160 pixels for 4K UHD.
With all the variables at play in these projectors it's hard to draw any firm conclusions from our testing. They vary widely in imaging technologies, native resolution of the chips, the use of either two-phase or four-phase pixel shifting, their brightness and native contrast, their image processing, and their optics. Perhaps one observation we can make is that a projector like the JVC DLA-NX7, with its trio of true native 4K chips, a good lens, and high native contrast, gives the best chance of delivering the most measurable detail to the screen compared with any pixel-shifting projector. But the two-phase pixel-shifting associated with TI's 0.66-inch DLP also appeared very capable of delivering something close to the full on-screen resolution of a UHD signal if embedded in a projector with good optics and even mediocre contrast, as we saw in the BenQ HT9060.
Less demonstrable from our tests here is what capabilities or limitations can be associated with the smaller DMD and four-phase pixel-shifting used in TI's 0.47-inch XPR DLP chip—the one that's typically included today in the most affordable 4K home theater projectors. The ViewSonic X10-4K was the only projector with this chip we had access to at the time of our testing, but it was built with a small form factor, portability, and ambient-light viewing in mind rather than an optimized home theater experience. Its results in our test could be attributed as easily to the inherent performance sacrifices of its design as to the imaging chip. The true efficacy of the 0.47-inch DLP imager is something that would need further exploration on a model with higher luminance, contrast, and a high quality zoom lens.
Another observation our test reinforced is that pixel resolution is only one component of image quality that helps to define how much detail we perceive on the screen. As mentioned in Part 1, much of the differences we saw up close in the magnified test target were not easily detected at normal viewing distance, and in the Mantis photo, the variations in color balance and dimensionality resulting from differences in contrast were much more obvious from across the room. Contrast definitely plays a big role in helping to improve our perception of sharpness and detail, as well as font readability. Despite their inability to produce the finest lines in the target, both the JVC DLA-X790 and Epson HC5050UBe got very high marks for their overall image quality on real content, with the Epson's wide color gamut also a plus. Similarly, although the BenQ HT9060 produced the highest resolution (and luminance) of any of the DLP pixel-shifters, with high color accuracy in the Rec.709 space, its lower contrast allowed the Optoma UHD60—a projector with the same 0.66-inch chip that costs a fifth of its price—to give the Benq a real challenge in perceived sharpness at normal viewing distances. That is the key takeaway for any discussion about 4K resolution: it's not just about pixels.