The 7 Best 4k Projectors
In Digital Projection, Mirrors Make The Difference
Those mirrors, shaped like little squares, are usually only five micrometers across.
Despite their diminutive stature, the mirrors inside the DMD don’t add up to the same number of pixels present in the intended image.
Mirror technology has come a long way since that dastardly reflective consultant to the Wicked Queen of Snow White. And while somewhere along the way we lost the ability to interact with our mirrors on a personal or prophetic level, we have harnessed other incredible capabilities from mirrors that we've made exceedingly small.
In a digital projector, for example, the light that constitutes your image bounces off of an array of incredibly tiny mirrors called a Digital Micromirror Device before hitting the lens that provides its ultimate focus. Those mirrors, shaped like little squares, are usually only five micrometers across. A micrometer, for the record, is one millionth of a meter.
Despite their diminutive stature, the mirrors inside the DMD don’t add up to the same number of pixels present in the intended image. A 4K projector puts out an image that should contain 8,294,400 pixels, but the average DMD only contains half that many mirrors. On the one hand, this is because it’s rather expensive to produce millions of flawless, microscopic mirrors. On the other hand, it’s because the scientific minds that designed your projector knew that your eyes couldn’t tell the difference.
Thanks to phenomenon called wobulation, these projectors only need to supply you with about half of the necessary information in a given frame, as the projection itself moves on to the next frame before your mind could ever catch up. It’s also convenient for their manufacturing costs that the human brain’s frame rate is shamefully slow, even compared to the 24-frames-per-second speed of the cinema.
Home Sweet Home Theater
Fewer people than ever seem interested in going to the movies. Between the drive, the parking lot, the lines, and the prices, it often makes more sense to stay home. Positive blips in the numbers shouldn't fool you; the industry is in trouble. Every once in a while there will be a good year, bolstered by successive successes among the major studios' big tentpole franchises like Star Wars or Jurassic Park, but these are anomalies within a consistent downward trend. With those few major exceptions, no one can accurately predict what new properties will have any degree of success.
That uncertainty leads, unfortunately, to a steep rise in ticket and concession prices.
That uncertainty leads, unfortunately, to a steep rise in ticket and concession prices. For example, back in the early 1990s, it cost about $3.50 to get into the movies, and if you kept your ticket stub, many places would let you come back all day. Popcorn was $1.50 for a large, and a little box of candy cost no more than $1.25. Soda cost even less.
Nowadays, all that put together wouldn't even get you a popcorn, let alone get you in the door to see a film. So, more and more people are upgrading their home theater systems to provide them with the kind of moviegoing experience they used to look for down on Main Street.
Which isn't to say these projectors are only meant for movie lovers. Television broadcasts of sports and well-made shows look fantastic on them, especially when played on those units with an upscaling feature to make the most of your 1080p HD streams while we wait for the market and local internet speeds to catch up to 4K resolution. And gamers absolutely love a good projector for the available depth of detail in its blacks.
Some projectors will handle games better than others, however, and others are better suited for high-resolution cinema print transfers. Know what you want to use your projector for going into the purchase, and you'll get the most out it for years.
Projection Born In Darkness
To understand where modern projection began, one must reach back almost 2,500 years to the Chinese philosopher Mozi, who made the first known recorded reference to the camera obscura. This device, which lets light in through a very small hole, concentrates and redirects it onto a makeshift projection surface, could be as small as a shoebox or the size of an entire room.
Those two examples rely on an eyepiece, where the original designs of the camera obscura let their mirrors reflect the image onto a flat plane like a wall of wood or stone.
Take the idea of a periscope, or a child's toy spy glass that lets you see around corners, and you have an idea of how the camera obscura works. Those two examples rely on an eyepiece, where the original designs of the camera obscura let their mirrors reflect the image onto a flat plane like a wall of wood or stone.
Eventually, innovators experimented with the means for preserving the images cast on these surfaces, and gave birth to film photography. About 150 year later, digital image recording revolutionized the industry, leading to a new wave of technologies.
Really, if you follow the path that light travels through a modern digital projector, not a whole lot has changed since those early days. We're just using more concentrated, more powerful light sources, inverting the initial image so that it appears upright when projected, and we have an enormous amount of microscopic little mirrors instead of one single mirror that sends the image through precision lenses.