TVs, desktop monitors, and even laptops have embraced more pixels at lower prices, but high-resolution home theater and office projectors have lagged in affordability. So while 4K resolution (3,840 by 2,160 pixels) has long since taken over as the standard for flat-screen TVs, only now are 4K projectors dipping below $1,000 to reach the sweet spot as consumers’ preferred resolution. If you’re shopping for a 4K model, you need to know that some issues shake out a little differently than they do with 1080p and lower resolutions, and some new factors come into play, too. But if you choose carefully, you’ll have a big-screen image you’ll love—at least until 8K becomes the norm, and that’s not going to happen anytime soon.
What issues come into play at 4K resolution? Some factors were newly introduced with 4K projectors, notably support for high dynamic range (HDR) imaging, and a unique approach to native versus virtual resolution. Others, such as brightness and portability, need to be considered differently with 4K versus lower resolutions. And some—display technology, light source, audio, and input lag—are essentially the same as for any other projector. Let’s examine each issue in turn, starting with those specific to 4K.
The Native Resolution: Must My Projector Have a True 4K Chip?
Native resolution—the actual number of pixels that are physically on a chip—is a big deal for lower-resolution projectors. A projector with a 1,280-by-720-pixel chip can accept a 1080p (1,920-by-1,080-pixel) signal and downconvert it to a 720p image on screen. But no matter how high-quality its lens, the resulting image will have a soft focus versus that of an otherwise identical projector with a real 1080p chip. The same is not true, however, for 4K projectors. That’s partly because of a trick called “pixel shifting,” and partly because there are limits to human visual acuity (whether or not you need glasses).
Almost all projectors that offer a 4K image or its equivalent at prices below about $4,000 use one of two pixel-shifting techniques. The majority are based on 1080p DLP chips that use TI’s XPR fast-switch pixel shifting. This technology breaks each 4K frame into four sets of 1,920 by 1,080 pixels, then displays all four sets on screen one at a time, shifting the pixels’ position between each set. Your eye integrates all four sets into a single 4K image.
At this writing, the only projectors in this price range that use a different pixel-shifting technology are Epson’s 4K Pro-UHD models. The Epson scheme uses three 1080p LCD chips and puts two sets of 1,920 by 1,080 pixels onscreen per frame.
That sounds like only half of 4K, but surprisingly, Epson’s approach delivers image resolution—in the sense of ability to resolve detail—that’s indistinguishable from models based on TI’s pixel shifting. One reason is that your perception of image sharpness and detail depends on other factors besides pixel count, including contrast, lens quality, and video processing, at which Epson’s Pro-UHD projectors excel. Another reason is that your eyes (with apologies to them) aren’t exactly the Hubble Telescope—there’s only so much detail you can see.
Sit far enough back from a screen, and you won’t be able to tell the difference between a 4K image and VGA (640-by-480-pixel) resolution. An eagle might, but the human visual system can’t. As you get closer, the differences between resolution levels get easier to discern, but you’d have to be closer to the screen than is recommended for any given screen size to spot any difference between a TI XPR and an Epson Pro-UHD image. So when shopping for a 4K projector, don’t let the difference in pixel count affect your decision.
That’s especially true because the term “4K,” which more or less universally means 3,840 by 2,160 pixels for TVs, is occasionally used for other resolutions for projectors, such as the 4,096 by 2,160 used in digital cinema. Prices for projectors with those variations, however, start at $4,000 and up, making them less affordable than the models we’re focusing on here.
Do I Need HDR?
As you may already know, the improved image quality of 4K flat-screen TVs over 1080p models depends not only on quadrupled resolution but on the shift from standard dynamic range (SDR) to high dynamic range (HDR), which was introduced along with 4K. Unfortunately, current projectors simply can’t produce the peak brightness required by HDR, unless you make the image so small that you lose the inherent projector advantage of delivering a much larger image than any similarly priced TV or other display. Many have trouble delivering suitably dark blacks, as well. As a result, although many 4K projectors do offer HDR support, some don’t support it at all, and some of those that do don’t handle it well.
If you’re buying a projector for business presentations or education, and you want 4K resolution so you can show more detailed line graphics or make small text more readable, poor HDR handling or a lack of HDR won’t matter. In most situations, it won’t be an issue even if you include video in your presentations or show an occasional film in your classroom.
For home theater use and TV replacement, a projector with HDR support is better, at least in theory, than one without it, but the quality of HDR varies so much between projectors that you need to confirm from an independent source how well it actually works. That’s why we cover HDR quality separately from SDR quality in our reviews.
If I Want HDR, Which Formats Do I Need?
There are several HDR formats. To take advantage of any of them, your projector must specifically support it, which means you need to check before buying which HDR formats a projector supports and make sure they include those used by the image sources you want to watch.
The most common format for projectors is HDR10, which is the version on discs and is also widely supported by streaming services including Netflix and Hulu. Many projectors also support Hybrid Log Gamma, better known as HLG HDR or just HLG. Although less common among image sources than HDR10, it’s becoming more popular—it’s currently supported by YouTube, for example.
An upcoming format which should quickly become widespread is HDR10+. This builds on HDR10, both improving image quality and eliminating some of the manual adjustment HDR10 requires when switching from one image source to another. A fourth format, Dolby Vision, is common in TVs but exceedingly rare in projectors, and likely to stay that way due to technical issues.
How Bright Is Bright Enough?
The easiest way to know whether a projector offers sufficient brightness for your needs is to read some reviews of it. Ours discuss the usable image sizes we found to deliver the best image quality in different lighting conditions. They also mention the screen size (small, medium, or large) and type of setting (dark home theater, conference room, family room with ambient light) for which the projector is suited. (For more about screens, check out our guide to finding the right screen for your projector.)
It’s possible to calculate the exact brightness you need for SDR images. However, it takes some math, and depends on enough variables that there isn’t room to detail the process here. Briefly, the variables include screen size; ambient light level, which determines how bright an image you need; and screen gain, the ability of some screen materials to boost image brightness by reflecting more light toward the viewing area.
As a point of reference, using the most common recommendation for SDR brightness in a dark room, a projector rated at 500 ANSI lumens is bright enough to light up a 100-inch diagonal, 1.0-gain screen with a 16:9 aspect ratio. In the low to moderate level of ambient light in a typical family room, you’d need 1,200 lumens for the same screen size. For the brighter light of an office, you’d need 1,500.
But keep in mind that the best image quality almost always comes at a lower brightness than the projector’s rating (or its brightest available mode if the projector doesn’t live up to its rating). A good rule of thumb is that the mode you’ll want to use will usually be 40% to 50% as bright as the brightest mode.
Unfortunately, there is no widely accepted standard for how bright an image you need for HDR viewing, which makes it impossible to make broad recommendations for how bright a projector has to be. Some people recommend HDR brightness levels for dark rooms that almost everyone agrees would be too bright for SDR viewing. Others disagree, but still suggest levels near the top of the range for SDR.
These differences of opinion are due both to subjective preferences and to variations in how HDR is implemented from one projector to the next. As a practical matter, unless you can test a projector for yourself, reviews like PCMag’s are your best source of information for deciding whether a given projector’s HDR image is bright enough for your needs. Pay particular attention to descriptions of HDR image brightness as distinct from SDR brightness, and whether the HDR image is suitably bright at the same image size used for SDR or seems darker overall.
Should I Get a Portable 4K Projector?
At this writing, there are no palmtop or pico projectors with 4K (or virtual 4K) resolution, and none that works on battery power. The most portable 4K model is at the high end of the mini projector range, but only if you stretch the definition of “mini” to just under 4 pounds.
You can also find room-to-room portable projectors, which are just a few pounds heavier. Too bulky for briefcases or backpacks, they’re suitable for carrying from one room to another or to the backyard (with extension cord) for an outdoor movie night.
What Are My Choices in Display Technology, and How Do They Differ?
As mentioned earlier, there are currently only two display technology options for affordable 4K and 4K-equivalent projectors: DLP (what most manufacturers use) and LCD (from Epson). The key advantage for DLP models is price: Between projectors with similar features and image quality, DLP units cost less. In addition, DLP is currently your only choice for a less expensive entry-level or portable projector.
The main advantage of LCD technology is the same for 4K as for 1080p: It can’t produce rainbow artifacts. These flashes of red, green, and blue come from using a single chip for all three primary colors and rotating through the colors in sequence. LCD projectors (except for a few lower-resolution portables) use three chips rather than one, which lets them project all three primary colors on the screen at once.
Some DLP projectors are more prone to showing rainbow artifacts than others, and some people see these artifacts more readily than others, so you may or may not see them with any given DLP model. For business and education applications, most viewers will consider occasional rainbow artifacts at least tolerable for presentations. Whether you’ll consider them an issue for home entertainment or home theater depends on how often you see them with a given projector, and whether you’re annoyed by or don’t mind them.
If you don’t see these artifacts or don’t find them bothersome, more power to you. However, some people see rainbow artifacts so easily and find them so distracting that they can’t enjoy watching videos or movies with a DLP projector. If you’re in this group, you definitely want a three-chip LCD model.
If you can tolerate some rainbows but not too many, you may or may not be happy with any given DLP projector. Our reviews always mention whether we saw these artifacts and, if so, how often. But because you may see them either more or less easily than our reviewer, we suggest that if you’re bothered (or don’t know if you’re bothered) by rainbow artifacts, try to buy from a dealer who allows easy returns without a restocking fee so you can test the projector out for yourself.
Which Type of Light Source Is Best?
More and more projectors today use solid-state light sources, meaning LEDs or lasers, but there are still some advantages to traditional lamps and still plenty of projectors that use them.
For the best possible image quality in a dark room, a well-designed home theater projector with a lamp will deliver darker black levels than a solid-state light source, as well as better contrast, which translates to more visually dramatic dark scenes. The darker blacks make a significant difference only when viewing in a dark room, which largely eliminates this advantage if you’re buying a projector for office or classroom use, or for home entertainment in a room with ambient light.
Another advantage of traditional lamps is that they cost less than LEDs and lasers, so a lamp-based projector will be less expensive than an otherwise identical solid-state model. However, if you keep the projector long enough to need one or more lamp replacements, your total cost of ownership may be about the same. When comparing a less expensive lamp-based projector to a more costly one with an LED or laser light source, be sure to check the cost of replacement lamps—often as much as $300 or more—as well as how often you’ll need to replace them.
The primary advantages of solid-state light sources are their longer life and slower loss of brightness as they age. A typical lamp will lose about 25% of its brightness over the first 500 hours of use, then continue to lose brightness more slowly until it needs replacement. Both LEDs and lasers will pretty much last for the life of the projector, or 20,000 to 30,000 hours. They also lose brightness as they age, but the loss is less precipitous and more of a straight line. That means they retain more than 75% of their original brightness considerably longer than lamps do, both in terms of hours of use and percentage of lifespan.
What about choosing between LEDs and lasers? LED projectors are more likely to have oversaturated color, but not all models necessarily have that problem. Similarly, lasers theoretically allow higher brightness levels, but in real life lasers’ and LEDs’ available brightness overlaps. Just pick a projector with good color accuracy and the brightness you need, and don’t make assumptions based on the technology.
Note that when comparing projector brightness, you should limit your comparisons to ANSI or the equivalent ISO lumen ratings. There is no standard for LED lumens, which makes comparisons meaningless.
Is the Projector Fast Enough to Play Video Games?
Input lag, measured in milliseconds (ms), is the amount of time between a projector’s receiving a video frame and showing it on your screen. If you’re making a business or classroom presentation or watching movies and videos, even a long lag won’t matter. If you’re projecting a first-person shooter game, a lower lag can make the difference between surviving to the next frame or not.
The input lag of any given projector will vary with its resolution and refresh rate. (The latter is the measure of how often the screen image is redrawn.) Doubling the refresh rate will generally cut the lag in half. However, a projector capable of a 240Hz refresh rate at 1080p resolution will likely be limited to 60Hz at 4K, thus an input lag that’s four times as long. For current gaming projectors with the shortest available input lag, that translates to roughly 4ms at 1080p/240Hz and 17ms at 4K/60Hz.
Obviously, the input lag that matters to you is the one in effect at the resolution and refresh rate you plan to use. Hardcore gamers should look for input lag measures of no more than 16ms or 17ms at their desired settings. Casual gamers may be comfortable with lags up to about 50ms, or a bit more. In either case, lower lag time is always better.
Do I Need External Audio?
The conventional wisdom in the projector business has long been that people who need high-quality or high-volume audio are going to use external soundbars or speakers, so there’s little point in trying to build a deluxe sound system into the projector itself. For that reason, home theater projectors traditionally don’t have any onboard audio.
Most projectors designed for business or education, by contrast, include an audio system, but in many cases it’s just a convenience feature with volume far too low for the size of the room the projector is likely to be used in. Sound quality is usually tolerable, but rarely better than that. If you’re buying a projector for these applications, be sure to check for both audio quality and volume.
Recently, manufacturers have begun to target some projectors specifically as TV replacements, raising the audio quality in those designs to match the intended task. The two categories of 4K projectors most likely to offer decent onboard sound systems are ultra short throw (UST) laser projectors and room-to-room portables.
The UST models, which are often billed as TV replacements or simply TVs, are typically of a size and shape that makes it easy to add what amounts to a built-in soundbar on the side facing viewers. Room-to-room portables, most weighing roughly 6 to 9 pounds, often have a nearly cubical shape, with enough room inside the box for surprisingly high-quality audio.
So, Which 4K Projector Should I Buy?
The good news is that the number of affordable 4K projectors is climbing quickly, making it ever easier to find one that fits your needs and budget. The favorites listed here, with links to detailed reviews, are the best 4K or 4K-equivalent models we’ve tested for various usage cases and price points, and a good starting point for your search.
