Lasers… the weapon in old sci-fi movies or Marvell cartoons. Also a nice toy for the cat. But lasers in a projector? Yeah… we now have these bright light sources under control in such a way that they can also prove their usefulness in projectors. Optoma has equipped the UHZ65 4K with such a sci-fi light source. And with a relatively favourable price tag: 4500 euros. But how does such a ‘laser-beamer’ perform now? Should we go directly to the eye surgeon for… never mind.
A few years ago 4K was for the happy few. But the way things are going nowadays: in no-time it will be commonplace. Many TV is 4K. Which doesn’t mean that the image quality is good, but that’s a different story.
With projectors, it’s a slightly different story. There, 4K is still pricey. Definitely ‘native’ 4K, where the sensor (at DLP) or the three LCD modules (in case of a 3LCD projector) are really 4K. A real, native 4K projector still costs a lot of money.
Now Texas – the only producer of DLP technology – has invented a trick: pixel shifting. The pixels – or small mirrors in the case of DLP – move from one place to another at lightning speed. So fast we don’t see it. As a result, there are more pixels to project than are actually processed on the chip.
In the case of the Optoma UHZ65, the chip contains 4.15 million ‘pixels’ – mirrors – which corresponds to a resolution of 2716 x 1528 pixels. With pixel-shifting, that’s 8.3 million, which comes out at 3840 x 2160 (8.29 million pixels). Enough for native 4K… Although, of course, it’s not native…
It’s a smart trick from Texas. By the way, there are also tricks within 3LCD that do something similar with 1080P lcd-chips. Now the resolution there is not 4K, but something between Full-HD and 4K. In theory, the Texas DLP technology should be sharper than that of the 3LCD projectors. In practice, it is almost invisible when watching movies.
Lasers… we immediately think of the destructive effect of a megalaser that explodes an entire planet through space. Fortunately, there are other applications. Think about eye correction, removing scars, car headlights and… projectors.
The nice thing about a laser is the extra light output, instant on and off, long lifespan (about two to three times as long as an ordinary lamp), less heat (and therefore silent operation of the projector) and in the case of this Optoma: a larger colour range.
Now there are several laser systems. Some projectors have a separate laser for R, G and B. Those are the 3LCD models. Some models have one (blue) laser passing through a color wheel. These are the DLP models.
Optoma has two blue lasers, one of which is converted to yellow. By combining the two lasers more brightness should be possible. Of course Optoma combines the two lasers with a colour wheel. It runs at 6x normal speed to minimize rainbowing; more about this later.