- Compact, light, and quiet
- Excellent resolution
- Laser lit: no lamp to replace
- Not very bright in the preferred home theater color mode
- Poor black level and contrast
- Ineffective HDR
The ViewSonic LS700-4K’s laser lighting is an attractive feature, offering significant long-term savings when priced against the periodic, expensive lamp replacements needed on a standard projector. This, plus its excellent resolution and relatively low price against the laser competition, make it a viable option for business applications. But it isn’t your best choice if pristine home theater performance is high on your list.
Those of us whose primary interest in projectors is for home theater use often forget (if we ever knew) that most projectors are sold into the pro market—businesses, schools, churches, museums, and movie theaters. The commercial and home theater models are usually designed differently, with dedicated home theater projectors emphasizing color accuracy and contrast in a dark room, and the pro models optimized for high brightness and color that works better in ambient light (digital cinema projectors being the exception). But occasionally, some projectors are marketed for a dual purpose, hopefully being as adept at providing quality video for home theater as they are at displaying computer graphics and spreadsheets in a business environment.
ViewSonic's LS700-4K is targeted to play in both sandboxes. And like most projector makers, the company has begun adding more models employing a laser as the light source. With laser lifetimes of 20,000 hours or higher you're more likely to replace the projector before the laser engine wears out. Moreover, while projection lamps begin degrading (dimming) from their first hour of use, lasers are far more stable over time. Until recently, though, laser projectors have been far less common than lamp-based designs for one primary reason: cost.
While the 3,300 ANSI-lumen LS700-4K isn't bargain-basement priced at its $3,499 list and just $2,100 street price, it's perhaps the first truly affordable laser projector we know of that promises 4K resolution. Just don't confuse it with its nearly identical sibling, the LS700HD, which sells for around $1,700 ($1,400 street price). The latter is also a laser projector, though limited to a maximum resolution of 1080p and standard dynamic range (SDR).
At 15.6 x 6.2 x 12.4 inches (WHD) and 15.7 pounds, the LS700-4K can't be described as a portable, but it is relatively compact and lightweight for a laser projector. Inside, it uses Texas Instruments' 0.47-inch, 4K, XPR DLP chipset, the smaller of TI's two 4K Digital Micromirror Devices. The larger DMD, at 0.66-inches, has 4.15 million pixels, while the 0.47-incher offers half that number. Both use pixel-shifting to display the full 8.3 million pixels in a 4K UHD image—some DLP manufacturers prefer to call it "fast-switching" to separate it from the 1080p pixel-shifters from Epson (and formerly JVC) that deliver something less than that number of pixels to the screen. [Editor's note: The "XPR" nomenclature used by DLP is said to stand for "eXpanded Pixel Resolution."] The smaller device used in the LS700-4K flashes four times to display all the pixels in each frame of a 4K UHD source (3840x2160), whereas the 0.66-inch version only needs to flash twice. While the full 4K content isn't all shown on the screen at the same time, as it is would be from a projector equipped with a true native 4K imaging device, the time displacement involved in the shifting is so rapid that the eye's persistence of vision blends it all together. It's arguable that the visible difference between this technique and the use of a native 4K imager is insignificant, particularly at a normal viewing distance.
The ViewSonic's light path begins with a single blue laser. The light from this laser strikes yellow and green phosphors positioned on a rotating wheel. The yellow and green light from the phosphors, combined with direct blue light from the laser, then strikes the main DLP color wheel to produce the full color spectrum. Finally, the light then passes through a prism and strikes the DMD chip before exiting through the projector's lens. No collimated laser light passes directly through the lens (as it might from a laser pointer, which can be a vision hazard).
The presence of a rotating color wheel in the LS400-4K immediately alerted me. Single-chip DLP color wheels often produce the so-called rainbow effect, a distracting artifact in which flashes of multicolored light are produced by some images, particularly bright highlights set against a dark background. Some viewers see this, others don't. I'm extremely sensitive to it, but pleased to report that I never spotted any RBE in my many hours of watching video on the LS400-4K .
One additional benefit of a laser light source is instantaneous on/off operation. The laser illumination doesn't need the warm-up/cool down periods required by a lamp, so there's no need for the battery backup many projector fans use to prevent lamp damage when there's a power failure and no fan running to provide a gradual cool down.
The connections on the projector's back panel include two HDMI ports (HDMI 1 is version 2.0 with HDCP 2.2, HDMI 2 is HDMI 2.0 with HDCP 1.4), mini USB (for service), wired LAN, a pair of VGA computer inputs, a VGA Monitor Out, composite video, audio in and out, and IEC power. I used only the HDMI inputs. A USB-A connection accepts a flash drive for loading media to the built-in reader. The LS700-4K also has a single built-in 2-watt speaker. It didn't play very loud and sounded pretty poor in any event; it might be suitable for spoken word in a small room but you'll likely want an outboard audio system for most installations.
The remote control is conveniently compact and backlit, though many of the buttons are small and were easily missed by my clumsy fingers. The projector's on-screen menu times out automatically after about 10-12 seconds, which I found annoying during setup. It has two remote IR sensors, one in the front and the other on top. The front sensor worked best when I was positioned in front of the projector and aimed the remote back toward it, rather than trying to bounce the signal off the screen. Aiming the remote at the ceiling, where the top sensor can catch it in a ceiling-bounce, provided me with the most consistent responses.
ViewSonic includes a 3-year limited parts and labor warranty, including 1-year on the light source, and a first year free of ViewSonic's Express Exchange service should that ever be required.
At turn-on the ViewSonic splash screen appears. It remains in place until you choose an input. If you select the Settings menu in the splash screen you'll get additional options that don't show up when you select Settings while on one of the operating inputs. The Settings menu is where you get the option of selecting Eco mode (Advanced>Light Source Mode>Eco), which reduces the brightess by about 20%. It could be helpful in some business environments, though you won't likely use it for home theater given the results to be covered below. The marketed 20,000-hour laser life is specified for both the Normal and Eco modes; no claim is made for additional hours in Eco as is found with some laser projectors. Out of the box, the Eco mode is turned off, and that's where I left it throughout this review.
The LS700-4K includes no vertical or horizontal lens shift—also somewhat unusual in the home theater realm among long-throw installation projectors—and both zoom and focus are manual. It has the usual options for front projection or rear projection setups from either a table or inverted ceiling mount, though ViewSonic also touts the option for 360-degree orientation, a common feature of laser projectors that might be used in a retail signage or museum environment but won't come into play in a traditional home theater.
The specified image size ranges from 60 to 300 inches diagonal. At my 10-foot setup distance the zoom range would fill the full width of screens from 87- to 112-inches wide—essentially confirming the specified zoom ratio of 1.3:1. While this ratio appears reasonable, it's lower than many home-theater-centric projectors offer. It also required placing the ViewSonic about 5-feet closer to my screens than I typically need with my current reference projector, a JVC DLA-X790.
Further complicating setup was that the LS700-4K has a steep fixed vertical projection angle upward from the middle of the lens, so it wants to be low in relation to the screen for a tabletop mount or above the screen for an inverted ceiling mount. Projecting a 100-inch, 16:9 image from a tabletop, for example, requires the center of the lens to sit 2.7 inches below the bottom of the screen. If you're unable to position the projector at the precise height, you can invoke the LS700-4K's vertical keystone correction (+/- 40%) as an alternative to the lack of lens shift. But this should be a last resort for any serious viewing, as keystone correction reduces both resolution and usually brightness to some degree (depending on how much is used). To make certain that the LS700-4K's setup options will work in your situation, you can check ProjectorCentral's ViewSonic LS700-4K Projector Throw Calculator to find the range of throw distances for your screen size. The user manual, available on ProjectorCentral's ViewSonic LS700-4K product page, provides the vertical offset for various image sizes.
In my case, I used two screens for my review, primarily an 87-inch wide (100-inch diagonal) Elite 16:9 (gain 1.0) and, briefly, a 96-inch wide (104-inch diagonal) Stewart Filmscreen Studiotek 130, 2.35:1 aspect ratio (gain 1.3). Both of them are solid matte white screens—that is, neither perforated nor woven for acoustical transparency—and neither is ambient-light rejecting. Except as noted, all of my viewing and calibration was done in a fully darkened room. Both screens are retractable and located within inches of each other.
While limited physical controls are located on the top of the projector, the basic on-screen menu includes Color Mode (Movie, User1, User2, Brightest, Sports, Standard, and Gaming), Brightness, Contrast, Color Temperature (User, 6500K, 7500K, 9300K), Noise Reduction, and Digital Zoom. There are also white balance controls, adjustable in the User Color Temperature setting, and a full color management system (CMS). But the white balance adjustments are for Gain only (RGB high level); there are no RGB Bias (low level) white balance controls, a significant omission and just one of many clues that the LS700-4K began life as a projector designed for business. (ViewSonic says RGB Bias will be added later via a firmware update, however.) There's no Sharpness control, and while global Saturation (color) and Tint controls appear in the menu, they were blanked out and inaccessible in all the color modes I tried; these controls are said to be available only for YUV signals.
An Advanced setup menu offers controls for Aspect Ratio, Frame Interpolation (motion smoothing), HDMI Setting (Full, Limited, Auto), and some limited Information on the source signal, including its resolution and 3D format settings. Yes, the LS700-4K does 3D.
Brilliant Color, developed by Texas Instruments, has long been a feature offered in DLP projectors. I used it throughout this review, engaging it to maximum (10) prior to calibration. Without it the projector wouldn't reach a reasonable Movie mode brightness level, even in HDR.
In the "Movie" color mode that's most geared toward home theater use, a filter drops into the light path to optimize the color gamut. ViewSonic calls this its proprietary Notch Filter Technology (though other projector manufacturers, such as from JVC, use a similar filter technique). The downside to the filter is a considerable drop in brightness; we measured 2,844 ANSI lumens in the Brightest mode and just 974 ANSI lumens in Movie. ViewSonic says that its Cinema SuperColor Technology can achieve 99.7% of Rec.709 color in this filtered Movie mode, though the projector makes no claim for any coverage of the expanded DCI-P3 or BT.2020 space used for 4K/HDR.
My measurements and calibrations were made using CalMAN measurement software from Portrait Displays, together with a Klein K-10A colorimeter profiled against a Photo Research PR-650 spectroradiometer, and a Fresco Six-G test pattern generator from Murideo/AVPro.
Out of the box, the ViewSonic wouldn't produce video at above white or below black, information that's needed to correctly set the Brightness and Contrast controls. Only if the source is set to deliver RGB (at the 16-235 video level range), and the HDMI Setting in the projector's Advanced setup menu is set to Full, can the proper black and white video levels be displayed and enable you to dial in the correct Brightness and Contrast settings. Most other consumer video sources generate YCbCr component video by default rather than an RGB signal, and most consumer projectors can use it properly. Some source devices might not even offer the RGB (16-235) color format, but it was selectable on both my Oppo Ultra HD Blu-ray player and the Murideo signal generator. Business projectors generally expect to see RGB from a computer rather than the YCbCr common in the video source world. This was yet another indication of the LS700-4K's business-born DNA.
Those changes made, I found that for SDR viewing, the "Movie" color mode, while far from bright, produced the most accurate images. But before calibration, even in Movie, the results weren't particularly good. Delta E is a figure of merit for accuracy in video measurements. Numbers lower than 3.0—some argue 4.0—are generally deemed indistinguishable from ideal and values up to 10, while visible, are unlikely to trouble the average viewer. The ViewSonic's pre-calibration SDR values for white balance ranged from 6.1 at 20% brightness to 12.3 at 90%. The Delta E's for its primary and secondary color points maxed out at 13.7 (in the Cyan secondary). After calibration, the white balance Delta E was 4.6 or below from 20% to 90% brightness, but 14.9 at 100%. The color point calibration produced a high of 4.2 in blue and no more than 3.8 in the other colors. The measured gammas remained close to my preferred settings of either 2.2 or 2.35 (1.8, 2.0, and 2.5 are also available, plus Cubic and sRGB—the latter two I'm unfamiliar with).
Most calibration results are measured at a fixed saturation level. For SDR this is typically 75%. But a saturation sweep shows how accurately a display's color is reproduced over a range of saturation levels. A post-calibration SDR saturation sweep on the ViewSonic produced satisfactory but uninspiring results—not a rare outcome for this difficult test. A Color Checker test, which measures the Delta E's at dozens of different real-world colors—not just the primaries (RGB) and secondaries (CMY) measured in the standard tests—produced relatively poor results, with an average Delta E of 5.4 and a maximum of 15.5.
SDR Viewing. I viewed standard dynamic range (SDR) from 1080i and 1080p (Full HD) sources and let the projector do the honors in upscaling them to 4K. The projector upconverted cleanly to its 4K resolution, tripping up slightly only by not upconverting quite as flawlessly as an Oppo Ultra HD Blu-ray player. But the differences were visible only on specialized test patterns, never on real program material. Screen uniformity was subjectively good (see the Measurements section at the end of the review), and I didn't spot any posterization or false contouring, though it's always possible that material I didn't watch might trigger it.
In the Movie color mode, the post calibration results didn't exactly produce brightness to die for, nor were the projector's black levels very impressive. After calibration, the peak white level on my Elite screen was a modest 12.93 foot-Lamberts (44 nits), with a black level of 0.038 ft-L, for a full-on/full-off contrast ratio of 340:1 measured off the screen. Looking for a bit more useful brightness from the projector, I increased the post calibration Contrast (peak white) to 25. This moved whites to the edge of clipping, but the extra punch was worth it; at these peak brightness levels every nit is gold. After that tweak, the peak white level was then 14.8 ft-L (just over 50 nits). This was in the longest minimum zoom setting (the smallest picture). Moving the zoom to the widest, maximum setting, while moving the projector in to keep the picture size unchanged, produced a peak white level of 15.5 ft-L or 53 nits. But I used the minimum zoom setup for all my viewing; the projector's location was less intrusive at the longer distance. All of these results reflect the projector's lack of full calibration adjustments, including more extensive white balance controls. Gain controls alone are simply not enough for a projector with serious video ambitions.
Nevertheless, the ViewSonic's images, on a wide range of SDR material, defied the numbers. My main negative observation, post calibration, was that light flesh tones often looked a little sunburned. But reducing the Red Gain white balance control by about 5 percent from its calibrated setting achieved more than acceptable results on most source material.
All of my sources were from Blu-ray disc. Kate & Leopold is an underrated 2001 romantic comedy framed by a clever time-travel McGuffin, though the story overall is more fish-out-of-water than sci-fi. When I first loaded it into my Oppo player my reaction was, "yikes, that looks way too sepia-toned." Then I recalled that its opening scenes are flashbacks to the 1870s and the rosy tint is intentional. The colors were more neutral when the action moved to the present day. As the color checker test indicated, they likely weren't 100% accurate. But without the colorist who produced the excellent transfer on hand, or the director, no one would likely see them as wrong. Flesh tones, while not consistently spot-on, were believable. It was also no surprise that detail resolution was superb, with skin and clothing textures showing every pore and thread in a way at which DLP consistently excels.
Life of Pi is another great Blu-ray that was generally impressive on the ViewSonic. The colors looked right, from the opening scenes in India to the vast blue expanse of the empty but always threatening ocean. Flesh tones on the main Indian characters were inherently slightly darker than the Caucasian pinks on Kate & Leopold's protagonists, so they never appeared off to my eyes. Dark scenes also looked a bit better than expected given the LS700-4K's poor measured black levels, likely helped by the fact that the blacks were often masked by the eye being drawn to brighter highlights in the same shot. In a scene in which Pi hallucinates as he gazes into the dark ocean, your eyes are distracted from the blacks of the ocean depths by brightly lit sea creatures in the foreground.
But here, and in similar scenes, it doesn't take long to notice that this projector's blacks are clearly medium-gray rather than inky black. The dark cave sequences in Prometheus, one of my frequently used dark-scene demos, never really came to life on the ViewSonic. Though I could always spot enough detail in dark scenes to follow the action, I've seen the same sources on better displays and know that much more than simple intelligibility is part of the experience when a display's blacks and contrast are deep and rich. This is also true of the black bars on widescreen films. The more visible they are, as here, the more they not only distract also but call your attention to the imperfect blacks in the images themselves. To be fair, no projected blacks can equal the contrast available from the best flat-screen sets, which is why I usually use a 2.35:1 screen for widescreen films (though not here). The black bars then fall off the active screen area and become invisible, enhancing the subjective contrast of the images themselves, though in reality it's never perfect.
Occasionally the LS700-4K's laser light source turned off completely in response to a totally dark image, usually on a fade-out between scenes. But this was inconsistent and offered no advantage in either the black levels or contrast. It was mostly a distraction.
To be fair, I've never found black level and contrast to be a DLP strong suit. Nor was I put off in actual viewing by the ViewSonic's relatively limited brightness in its Movie color mode, the only one I can recommend for the best color. The eye adjusts, and while this mode appeared dim at first (my reference projector can easily exceed the ViewSonic's SDR output), it was acceptable when I settled on the best adjustments and used it in a completely dark room. In reality, few movie theaters can exceed the ViewSonic's peak brightness (IMAX and Dolby Cinema excepted), and many theaters offer far less.
HDR Viewing. Unfortunately, I was never able to achieve anything close to an acceptable high dynamic range image on the ViewSonic. In no setup I tried was its HDR picture anywhere near as pleasing in its contrast and punch as it was with the same material in SDR. The problem was compounded by the projector's lack of full white balance adjustments for use in calibration (these are even more critical for HDR than in SDR). I also tried relentlessly, but without success, to find any settings that offered an even remotely close match to the HDR10 EOTF (Electro Optical Transfer Function—that is, the gamma curve for HDR).
The projector offers three settings for EOTF: Low, Middle, and High. But the EOTF is supposed to be fixed at specific levels. There's no allowance for user preferences. A display either adheres to the curve or it doesn't, until the brightness reaches the inevitable clipping point. But the LS700-4K consistently fell well short of generating enough peak output to come close to a correct EOTF. Through most of the brightness range it was dramatically dimmer than it should be. Without a reasonably useful EOTF there was no point in attempting a full color calibration, even if the projector's available calibration controls had been adequate for the job.
I did measure the peak output in Movie mode: 55.6 nits at 100 percent. That's nearly the same as for SDR, and hardly sufficient for good HDR even without considering the poor EOTF curve. I did measure a somewhat better peak of 114 nits (about 33 ft-L) in Standard mode, not bad for a projector. But again, the poor EOTF stood in the way of getting the kind of punchy HDR contrast that we associate with this format and which the best projectors achieve.
Some sources (including the Oppo UHD Blu-ray players) offer a setting that will turn off HDR in a 4K/HDR source while retaining the advanced color of Ultra HD, assuming the display is capable of displaying it. I tried this, and the result was better than with the projector seeing an HDR flag in the content and running with its automatic HDR adjustments. But, even then, with HDR defeated, the LS700-4K never looked as good playing a UHD disc as it did from an SDR disc of the same material. Since a 4K disc with the HDR defeated omits the effect of the EOTF curve, there must be something else going on here that limits the 4K-only (no HDR) picture. But since this is a review and not a research project on HDR, my investigations had to end there.
3D Viewing. In 3D mode all of the LS700-4K's standard adjustments are locked out. You can't choose a color mode, nor perform any significant tweaking of the picture. All that's available are a few controls in the Advanced menu. But with these presumably optimized default settings, the projector's 3D images were very dark and afflicted with ghosting, and I found them uncomfortable to watch.
Ambient-Light Viewing. Most of my criticisms above relate to the LS700-4K's use as a home theater projector in a fully darkened room. But as a multi-purpose device, where its long-life laser is a key feature and its video use will be limited to short business presentations and only the occasional movie, it should have wide appeal.
To assess how well the LS700-4K's picture will hold up in the limited light control available in a meeting room, I took it through its paces with a variety of SDR content in conditions that mimic that environment. I'm not talking about a bright porch on a beach house or a sun room, neither of which is suitable for any projector, but merely enough light to move around freely, allow reference to paper materials, take notes, and easily interact with others.
A screen with a slightly higher gain than my Elite (1.0) proved advantageous for this type of viewing. Using a color mode brighter than Movie added a further upside—sacrificing optimum color for added brightness. When I changed from my 1.0-gain Elite screen to my 1.3-gain Stewart Studiotek 130, without changing the image size, and also switched to the Standard color mode, the peak brightness increased to 43 foot-Lamberts (about 147 nits). If a change to an existing screen isn't possible, switching the color mode from Movie to Standard alone produced more than half of the increase. (These results were achieved with Standard mode settings as follows: Brightness 45, Contrast 25, Color Temperature 6500K, and Gamma 2.2.)
The Brightest color mode was marginally brighter than Standard, but it had a clearly visible shift toward green that some might find objectionable depending on the content. The Standard Color Mode also edges toward green, but its shift is subtler than in the Brightest mode and never annoying.
My Standard mode setup for ambient-light viewing was not color calibrated, but the colors ranged from believable to good. I watched the entire second half of the recent Super Bowl with two bright room lights turned on (positioned to the side of the screen where their light didn't fall directly onto it). Though the colors were a little off in this situation (but not so much that non-critical viewers would notice), I could see everything needed to follow the action on this and other uniformly bright images. Any loss of the dimmer Movie mode's richer and more accurate color, and superior (though still limited) contrast, is less critical when room lighting is needed for casual or business use. I also tried the Sports mode, which falls roughly between Standard and Brightest in peak white level. Its extra kick was welcome on the Super Bowl, and may be preferred by some viewers for watching sports in a well-lit room. But on other bright programming viewed in the same environment, it definitely showed a greenish cast that was most obvious on flesh tones—though not as much as seen in Brightest mode.
I was able to connect my Windows 10 computer to the ViewSonic via VGA and spent some time looking at the the small, fine lettering on two computer programs I use frequently, one of them the CalMAN software we use for video calibrations. The text was easily read from a distance, and any modest softness I saw was clearly related to the low 1024x768 output resolution of my computer. Full 1080p or 4K output for computer graphics should look nice and sharp in any business setting.
The ViewSonic LS700-4K's solid-state laser light source is a compelling feature for a 4K home theater projector that costs just $2,100. At this writing in early February 2020, it is the least expensive laser-driven UHD home theater projector in the ProjectorCentral projector database, and after putting aside some 4K specialty and ultra-short throw models that have popped up lately, you'd have to step up to the JVC LX-NZ3 at $3,699 to find another traditional long-throw 4K laser projector.
However, while its lack of need for a periodic lamp replacement may be attractive, if your application will be centered around video in a home theater setting, I can't readily recommend the LS700-4K as a substitute for a late-generation, lamp-based home theater projector in its price range. With a bit of calibration, its 1080p SDR images on the LS700-4K looked pretty good in my dark room theater, albeit less bright than some would prefer in its one optimal color mode. But its mediocre contrast and lack of prowess with 4K HDR images—including the inability to take advantage of the extended color gamut used today in HDR movies—suggest you could do better with a dedicated home theater projector designed with these qualities in mind rather than this one that seems to have roots in a business projector.
That said, when viewed as a business projector, and used mainly for presentations with an occasional foray into SDR video, the laser lighting offered here still comes at a great price, and the LS700-4K's other color modes offer considerably higher output for the less color-critical, high-ambient light conditions it's likely to be used in. Not only that, but its fairly compact size and weight among laser projectors, not to mention its medium-throw lens and steep vertical throw angle, lend themselves to temporary office set-ups where a projector may be frequently moved in and out of a storage closet or to different locations.
Given that I found weakness in the LS700-4K's HDR, for which you may have no need, a strong alternative to look into could be the ViewSonic LS700HD mentioned earlier. This sister model is essentially the same projector, also offering a laser light engine, but with 1080p resolution. Though we had no opportunity to compare it with the LS700-4K, at its current street price of only $1,399, it's a true bargain among laser projectors of any type.
Brightness. With the LS700-4K set for its Brightest picture mode, the laser Light Source control set to Normal (100% brightness), and the zoom lens at its widest position, our sample delivered 2,891 ANSI lumens. This is short of its full 3,300 ANSI lumen spec but within accepted manufacturing tolerances according to ViewSonic. The Movie mode, which was the most accurate for dark-room home theater use, engages a filter that helps achieve the specified Rec.709 color range but dramatically reduced brightness to 904 lumens as shown in the chart below. The Standard mode, with 1,677 lumens in our test, is recommended for normal daytime lighting conditions. Engaging the Eco Light Source setting is specified to reduce power by 20%; we measured a 27% reduction (73% power) on our sample. Following are the measurements for all color modes in Normal and Eco power settings.
ViewSonic LS700-4K ANSI Lumens
Zoom Lens Light Loss. As with all projectors, moving the zoom lens from its wide open to its longest (telephoto) position causes some degree of light loss. For the LS700-4K, this change resulted in a 11.2% loss of brightness.
Brightness Uniformity. Brightness uniformity measured 68%, a middling but acceptable result not uncommon in budget projectors. The LS700-4K's 9-point measurements showed fairly consistent brightness horizontally across the screen at any given screen height but increasing intensity as the image progressed from the top toward the bottom of the screen. Despite the measurements, no obvious hotspotting or shifting of uniformity was visible with either test patterns or any live material.
Input Lag. The LS700-4K, as measured with a Leo Bodnar 1080p tester, produced lag times of 66.3ms in either the Movie or Game modes. This is average for most home theater projectors and acceptable for casual gaming, but too slow for serious competition, where hardcore gamers typically seek input lag at or below 16 ms. We did not have an appropriate meter on hand to test the 4K input lag.
Fan Noise. On startup the projector's fan noise is above average. But it soon settles down, making this a respectably quiet projector in a large room. Casual measurements taken in the Normal power mode from approximately six feet from a side vent showed 36 dBA. Engaging Eco mode reduces the noise level by about 2 dBA, adding the High Altitude option to Normal mode (recommended above 1,500 meters/4,921 feet) adds about 6 dBA and could call for some form of acoustic isolation.
- HDMI (x2, one HDMI 2.0/HDCP 2.2, one HDMI 2.0/HDCP 1.4)
- USB 2.0, Type A (for media)
- Ethernet LAN (RJ45)
- Audio Out (3.5 mm)
- Audio In (3.5 mm)
- RS-232 (control)
- VGA In (x2, 15-pin)
- VGA Out (15-pin)
- Composite Video In (RCA)
- Mini USB (service only)
For more detailed specifications and connections, check out our ViewSonic LS700-4K projector page.