Putting a Big Picture in a Remarkably Small Pocket: 4 Mini Projectors Reviewed

With the warm spring beckoning us Northerners to the outdoors, thoughts of week-long beach vacations or camping trips bring on a serious dilemma: How in the world are we going to watch movies? OK, maybe, maybe not. But if you happen to be a millennial or a teenager with a smartphone, you know that its screen handily doubles these days for your old pappy’s big-screen TV. Except, it’s really not so big, is it? You can crowd in only so close when you’re trying to share your latest photos or a download of American Horror Story with a group of friends.

Today’s projector manufacturers have heard your cries for help, as well as those of business professionals who need to cart around projectors for presentations. And even the cries from guys like me, who, on a day off in a distant land, wouldn’t mind being able to watch a reasonably large and acceptably high-quality image of a high-def movie on whatever white wall happens to be nearby. After cocktail hour, anyway.

With this in mind, and a long-nagging curiosity about what these little boxes can actually do, I called in a few for a survey. And when I say little, I mean it. The largest of the four projectors I evaluated is but 6.5 inches wide x 1.3 high x 4 deep, about the size of a typical mass-market paperback book (if you still remember what those look like). The smallest, I kid you not, is about half the size of the iPhone you might use to drive it.

These projectors go by any number of descriptives, including pocket, mini, pico, and—I like this one—mini-beamer. What most have in common is that their diminutive size is made possible by none other than Digital Light Projection micromirror technology. Yes, that DLP—the one that helped revolutionize the home theater projector business, not to mention digital cinema.

DLP, for those unfamiliar, is based on a concept so preposterous on its face, it’s a miracle it even works, much less that Texas Instruments has disrupted entire industries with it and has now made it so ubiquitous and cheap that it’s available in projectors costing less than $200 on Amazon. At the heart of any DLP system is typically one DMD, or digital micromirror device (but sometimes, there are three). The DMD is an electro-optical chip, created using something akin to a semiconductor mass-fabrication process. A finished DMD has a silicon base, above which is suspended a multitude of tiny, square mirrors that nearly adjoin, like treetops in a rainforest canopy. Each mirror is suspended by a post and able to mechanically swivel between two positions, based on application of a static electric charge from below.

Each mirror represents a single pixel on the screen, and there can be millions on one chip; a 4K-resolution DMD has 8.8 million, each measuring less than one-fifth the width of a human hair. When a mirror is tilted to its on position, it reflects a beam from the projector’s light source that passes through the lens and on to the screen. Tilted to its off position, it dumps that light into an absorptive area, and that pixel goes dark on the screen. To get shades of gray, the mirrors oscillate rapidly—many thousands of times per second— to mitigate how much light strikes the screen.

Most single-chip DLP home theater projectors add color by sending the white light source through a multicolored filter wheel, or color wheel, that rapidly cycles among the primary colors. Signal processing coordinates the red, green, and blue picture information with those moments when the wheel is in the right spot to reproduce each color. But instead of using the typical high-intensity lamp and a delicate glass color wheel, which creates both bulk and the potential for damage from rough handling, these pico projectors typically use a multicolored LED light source or occasionally a laser. This eliminates the mechanical wheel, reduces size requirements, and makes these devices durable for travel and mobility.

Based on size and cost, you’ll find a wide variety of performance levels within the category. Along with their footprints, pico projectors vary greatly in their resolution and light output, not to mention the quality of their lens and optical elements, their connectivity, and their features. The smaller projectors produce less light but can be operated on battery power for true on-the-spot portability, while the more powerful units require a place to plug in for AC power. The four projectors under review here straddle both worlds. There are two shockingly tiny, battery-operated, breast-pocket projectors from Magnasonic and Sony, retailing for $170 and $350, respectively, and two somewhat larger and more fully featured models from Optoma and Vivitek, selling for $549 and $599. Three of the four are LED-driven DLP projectors; the Sony uses a laser light source and an alternative imaging device, as I’ll describe later. The projectors vary in resolution from a somewhat meager 650 x 360 pixels to 1920 x 800 pixels—essentially, 720p high definition. Rated light output among them runs from 25 to 800 lumens. So I was prepared for, and got, an interesting range of experiences.

I should add a note about audio: Each of these projectors has a tiny built-in speaker, which worked, barely, for reproducing intelligible dialogue and sounded about as good as you’d expect from a driver the size of a fingernail, powered by a wee 1- or 2-watt flea amp. But each projector also has a 3.5mm minijack audio output, into which I plugged my home theater rig for playback. This helped create an immersive experience irrespective of image size, though you probably won’t have a theater system nearby when you use these projectors in the field. A good portable powered speaker with an analog input is a highly recommended accessory if you plan to watch movies or music videos.

How We Tested
Given their small form factor and relatively low cost, it would be unfair to hold these products to the standards we apply to full-size home theater projectors, even the budget models we test. That said, a good picture is a good picture, and while we should expect to give up some image quality, maybe even a lot, for the convenience and wow-factor associated with whipping a credit-card-sized projector out of our jeans pocket in a social setting (my hero!), it’s helpful to understand the trade-offs and know how close these picos come to hitting an enthusiast’s sweet spot.

That said, I zeroed in on light output as the most critical attribute and came up with a repeatable test procedure to gauge each projector’s ability. First, I mounted the projector on a traditional camera tripod, which allowed me great ease in moving the projector’s distance from the screen and swiveling it up, down, right, or left to eliminate the keystone effect that results in non-parallel sides. This is a more prominent issue with temporary setups and small screen sizes. Most of the projectors had digital vertical keystone correction that I’d have been happy to tap for a one-time portable application, even though we strongly recommend that this be avoided in a permanent home theater installation to avoid artifacts or loss of sharpness. I skipped it here as well for purpose of evaluation.

For each projector, I set up first for a 65-inch-diagonal image as my preferred image size, on the thinking that if I’m carrying around a projector, even a small one, it would be nice to know it can deliver a reasonably viewable picture at least as large as a reference flat panel at home. For projectors that offer different video modes, I selected the one that had the best default color for movies. After measuring and recording peak white light output and throw distance at that 65-inch size (in a dark room and on my reference Stewart Filmscreen StudioTek 130 1.3-gain white matte screen), I physically moved the projector (none of these has an optical zoom adjustment) to whatever throw distance delivered 12 foot-lamberts of output, then measured how large an image the projector could cast at this brightness. I selected that number of 12 ft-L as about the lowest light output that any of our reviewers have successfully used in their darkened home theaters, though usually with a much larger image. I also measured black levels at both the 65-inch and 12-ft-L sizes to calculate contrast ratio figures. (Don’t consider them absolute, but you can use them for comparison among our test subjects.) Beyond this, I looked at the range of specified image sizes the manufacturer recommends and measured peak white at both the smallest and the largest image size advised for that unit. You can find my results in the accompanying chart.

Then, I looked at a few test patterns and some content. I viewed segments of Mission: Impossible—Rogue Nation and The Martian on Blu-ray through each projector’s HDMI input from my Oppo BDP-103 universal disc player. I also watched an Amazon Prime high-def download of Ex Machina via my iPad 2 through a 30-pin-to-HDMI adapter and checked out some live high-def and standard-def YouTube streams, on the thinking that a portable device is likely to be the source in most applications. Along those lines, I also fed those projectors that featured a USB input and an integrated media player some standard-def video clips from a thumb drive.

Although I created a level playing field to compare these projectors in a highly favorable environment, the nature of how they’re used will likely put them in less ideal conditions. All front projectors do better in a pitch-black room; that might work for night-time movie viewing, but not a business presentation. And a white sheet or a white/off-white painted wall won’t likely have the reflective properties of my reference screen. That said, the two brightest of these projectors did produce a surprisingly watchable image even with the room lights on, and so did the little guys if the image was small enough. Be prepared to adjust your expectations and ratchet down your screen size, maybe to a large degree. But whatever situation you find yourself in, if the goal is simply to get a decent picture up that a small group can enjoy, you can probably get by with any of these.