Is UHD really 4K?

Resolutions

With any new technology, the terminology can be baffling. And resolution terminology can be the most confusing of all!

Resolution is simply the number of pixels in an image. The higher the number of pixels, the greater the resolution and the better the image quality will be.

 

Resolutions are as follows:

  • UHD 4K (3840 x 2160) pixels
  • WUXGA (1920×1200) pixels
  • Full HD 1080p (1920 x 1080) pixels
  • WXGA / HD Ready (1280 x 800) pixels
  • XGA (1024 x 768) pixels

 

Optoma 4K Ultra High Definition (UHD) projectors provide four times as many pixels as Full HD 1080p. That’s 8.3 million on screen pixels (3840 x 2160) bringing greater realism to every scene with increased depth and light and shadow detail for a truly immersive experience.

The UHZ65, UHD60, UHD550X and UHD65 all use a 4M pixel chip.  The latter 4K UHD models - UHD40 and UD51 use a 2M pixel chip. But Optoma UHD 4K projectors do not pixel shift in the same way as the 3LCD ‘4K enhanced’ projectors from Epson and JVC.

To get your head around this, let me give a simple overview of how each technology works.

A projector using 3LCD technology splits the white light from its lamp into three colour beams and directs each to their own LCD panel to create the image to be projected.

At the heart of every Optoma projector is a DLP® chip. Developed by Texas Instruments, this chip has millions of microscopic mirrors, each measuring less than one-fifth the width of a human hair and each corresponding to one pixel on the final projected image. A spinning colour wheel made up of coloured segments is placed between the light source and the chip. The mirrors are then turned on and off perfectly in time with the right colour – allowing the projector to display a total of 16.7 million different colours for a fantastically vibrant, life-like picture. By using mirrors rather than LCD panels, DLP projectors are shown to have better pixel alignment and therefore show a sharper image.

DLP chip

Optoma’s 4K UHD projectors with over four million mirrors (UHD60, UHD65, UHZ65) deliver two discrete pixels for each mirror. UHD40 and UHD51 deliver four discrete pixels for each mirror.  The inherent fast switching speed of the DLP chip and Texas Instruments’ latest XPR™ technology allow the projectors to display the full 8.3M pixels to the screen from these pixel chips. This happens so fast that the eye blends them into one image.

The ‘4K-enhanced’ 3LCD projectors from Epson and JVC use native HD 1080p chips (1920x1080). To achieve ‘4K-enhanced’ they project a 1920x1080 image, then on the next refresh of the chips a second 1920x1080 image is off-shifted diagonally and overlaid onto the first. The total number of addressable pixels in this process is 2x (1920x1080) = 4.15 million - half of the 8.3 million in a native 4K signal.

The Consumer Technology Association (CTA) defines 4K UHD resolution as 3840 x 2160 or greater than 8 million addressable pixels. For projection systems, 4K and 4K UHD resolution should be defined by the on-screen counting of pixels or the ability to see greater than 8 million dots.

With the full 8.3 million on-screen pixels, Optoma’s 4K UHD projectors meet the Consumer Technology Association (CTA) requirements for 4K UHD and CTA High Dynamic Range (HDR) compatible display standards.

Among the smallest 4K projectors on the market, Optoma’s 4K UHD projectors set a new benchmark in performance.