4K is not 4K is not 4K - Rapallo

4K is not 4K is not 4K

Written by Published | Rapallo AV Team
Rapallo | Sony VPL-VW890ES 4K Home Theatre Laser Projector

4K is not 4K is not 4K right…no one in his right mind would argue that true (native) 4K projectors are cheap.

There is no denying that the Sony’s VPL-VW5000ES is a truly amazing projector.  I mean, it’s boasting 5000 lumen true 4K.  It’s a beast by home theatre standards and it is liquid cooled.  But at a price of more or less $80,000, it’s not for the average Joe. Admittedly, there are much cheaper true 4K’s around, but they still remain well outside most New Zealand customers budgets.  

A decent 1080p projector by contrast sits around the $3,000-$5,000 mark. 4K resolution may make a glorious image, it’s hard to justify this difference in price for most of us. The main reason for that, is that 1080p chips are much less costly than 4K chips.

But -and here’s the good news- until the price of true 4K comes down, there is some excellent compromise to be found in pixel shifting.

At the moment there are pixel shifting technologies available that offer an alternative to true 4K with a sharper, more detailed image than standard 1080p and retail at a price point closer to standard 1080p.

Interesting, I’m sure you would agree.

Time to explain this whole Pixel shifting idea:

Though there are different ways in which different brands achieve this effect, the basic concept is the same.

An image is projected onto the screen with an initial scan of the chips in native 1080p format. Then on the next refresh of the chips the light in the engine is re-fired with different data, diagonally 1/2 pixel away. The system alternates back and forth, scanning between its native position and its offset position so rapidly that the eye can’t detect any sequencing or overlaying of one image on top of the other.

It’s fair to say that just overlaying two slightly offset discrete 1080p images would just blur the image. It won’t surprise you that this takes some really good processing, blending and integrating both images together. The end result however, is a picture that looks much sharper than standard 1080p.

Epson and JVC are masters at pixel shifting. That said, the result is rather impressive, we think.

The Epson TW9300, as well as the TW8300, are marketed as “4K enhanced” projectors.  (At no stage have JVC or Epson been marketing these pixel-shifting projectors as ‘true 4K’.) They accept native 4K video signals and are HDCP 2.2 compliant. However, rather than using native 4K resolution imaging devices, they use 1080p 3LCD panels with a pixel shift technology that enables them to approximate the resolution of a native 4K projector.

JVC were the initiators of the whole pixel shifting technology (E-Shift) and have fine-tuned it over the years. All their projectors are equipped with the technology, apart from the newly announced DLA-RS4500 true 4K projector (This is the announced US name. Names tend to differ in NZ)

But wait… there is more!

While 4K offers 8 megapixels chips, 1080p goes with 2 megapixel chips.

In 2016 Texas Instruments (TI) caused a bit of talk about a new 4megapixel chip, resulting in just under 3,000 pixels across (instead of 3840, the true 4K home theatre standard).   This means we are now dealing with a third class ‘3K projectors’, which is higher resolution than the “2K pixel shifters”.  (Please read that carefully – we’re talking 4 megapixels, not 4K resolution.)

But here’s the interesting bit: TI’s new chip will have pixel shifting capabilities so that will place their new projectors that use it, almost exactly half way between the 2K pixel shifters, and the native/true 4K projectors when it comes to resolution.

The thing is that the UHD 4K standard counts the new TI chip as being 4K.  The argument is based on ‘addressability’, though not resolution.  Since the chip has 4 million pixels, and each one fires once, then shifts and fires again, with possibly different data, that’s 8 million addressable, which is the same number has having a true 4K chip with each pixel firing only once. This could be interesting business….

Since TI and DLP projectors go hand in hand, it makes sense that it would be DLP projectors like Benq and Optoma that would be the ones introducing this technology. At this stage BenQ has released the first of those 4 Megapixel DLP projectors with their W11000 and their X12000. Optoma introduced its UHD60 at the start of this year.

Obviously, the pros and cons of DLP are most likely going to play a role: potential rainbow effect (although this seems to be less and less of an issue), faster processing than LCD and LCoS, but LCD/LCoS tends to perform better when it comes to contrast ratio and black levels. It will be interesting to see if this new DLP chip can give the LCD/LCoS-based competitors (Sony, Epson, JVC) a run for their money.

Source: Projector reviews, JVC, Epson, Optoma, BenQ, Cnet