Is it 4K Yet?

Any flat screen TV advertised as 4K will actually display the full 8 million pixels in a 4K (3840 x 2160) source. You can't be certain about how well it will do a wider color gamut or high dynamic range—the other keystones of Ultra HD—but it will put 8 million discrete pixels on the screen. Whether or not the 4K source material is actually true 4K from the camera to your Ultra HD disc is a different issue for another discussion.

But with projectors there are two versions of 4K resolution, the professional 4096 x 2160 (this is what you'll see in the multiplex), and the consumer 3840 x 2160. The latter was chosen because it's a simple 2-times multiple of our HD format's 1920 x 1080 (often referred to as Full HD). But the shorthand of 4K is used in referring to both, rather than a clumsier 4K and 3.8K. We could ignore 4096 x 2160 for this discussion if not for the fact that Sony, which offers the widest range of Full 4K projectors (more in a minute as to what I mean by "Full 4K") has decided to use 4096 x 2160 imaging chips for its consumer designs. Practically speaking, however, this is a non-issue; those projectors merely leave 128 pixels blank at the left and right of the picture when displaying consumer 4K material. Those unused pixels disappear into the borders when you zoom your Sony 4K projector to fit the full width of your screen.

A "Full 4K" projector, which isn't common terminology and not something you're not likely to read about in the popular press or hear in a sales pitch, is a projector with an imaging chip or chips that provide a 3840 x 2160 pixel array. Every pixel in each 4K frame is flashed on the screen at the same instant in time, just as it is in a 4K flat screen set or the professional projectors in your local multiplex. But this can be pricey; Sony brought out a $5000 consumer model just this year, the VPL-VW285ES, but it's all up from there.

Not surprisingly, manufacturers have found clever and more economical ways of getting closer to Full 4K without actually going all the way. It all started several years ago when JVC introduced pixel shifting, or as they call it, e-shift. The projector accepts a 4K source with its approximately 8 million pixels, then processes them down to 4 million. It then separates these 4 million pixels into two sub-frames, each of them 1920 x 1080. It displays the first sub frame on its conventional 1920 x 1080 imaging chips, then shifts the image by less than a full pixel and displays the second, all in an instant. It may sound bizarre, but while it isn't Full 4K, the eye's persistence of vision, plus its limited detail perception at a normal viewing distance, allows it to work remarkably well. JVC was first out of the gate with this technique, but Epson is also now very much in the game (the diagram at the top of this blog is from Epson). Both companies use three imaging chips, one each for red, green, and blue, either LCD (all but one of Epson's models) or LCOS (Liquid Crystal on Silicon—though Epson's top consumer model uses a similar Liquid Crystal on Quartz). JVC does offer one Full 4K LCOS design, but its priced at a stratospheric $35,000.

Texas Instruments, the inventor of DLP technology wasn't about to sit on its hands with all of this going on. Just last year it came out with a new DLP imaging chip, the DLP66 (0.66 cm diagonal) offering a resolution of 2716 x 1528, or just over 4 million pixels. Using pixel shifting with this chip, it can put all of the 8+ million pixels in a 4K source onto the screen, displaced only in time, with no need to process the signal's original 8 million pixels down to 4 million as is the case in JVC's and Epson's solution. This year TI also launched another such solution using a DLP47 (0.47 cm diagonal), imaging chip. Using this chip's conventional 1920 x 1080, 2 million pixel resolution, it divides the 8 million pixels in each 4K frame into four 2 million pixel sub-frames, then shifts and flashes 4-times (rather than the 2-times in the DLP66). Again, all of the pixels in the 4K source are displayed, unlike the shifting used by JVC and Epson, but not at the same time as they would be in a Full 4K design like the Sony mentioned above. TI also argues for another advantage from their technique; unlike the LCD and LCOS projectors that must perfectly align the images produced by each of their three chips, a single-chip DLP solution can produce an inherently sharper picture.

One question remains, however. Can an image be called true 4K if the full complement of the 8 million pixels don't reach your eye at the same instant? No one has yet answered that, nor does there appear to be any movement toward doing so. The UHD Alliance, an industry group that has established certain (roughly enforced) standards for Ultra HD, appears primarily interested in the flat screen TV market, which means 99% of consumer 4K displays. It's unlikely the Alliance gave much thought to the solutions used by JVC and Epson, and none at all to TI's (which didn't exist outside of the lab when the Alliance first did its work).

The short answer, for now, is that the consumer must decide if this is an important concern in a purchase decision. I will say that in my experience with TI's DLP solution (I've only spent quality time with an Optoma using the DLP66 chip), they can be look exceptionally crisp without obvious artifacts (apart from the rainbows that can be an ever present distraction to those of us sensitive to them—not all viewers are) Comparably priced JVC and Epson pixel shifters, while less achingly sharp, don't appear to leave any important detail on the table while excelling in wider color and impressive contrast—the latter a notable weakness in the DLP's I've seen, though I certainly haven't seen them all.

But JVC and Epson, while not waving a red flag in front of potential buyers, at least make a point of their approach by using 4K e-shift and 4K Enhancement, respectively, in their promotional materials and specifications. I haven't noticed any similar hedging in the"4K" DLPs released so far, with those makers following TI's lead in calling their projectors true 4K. They do have a point; all of the pixels are indeed up there on the screen. But just not at the same time.

jnemesh's picture

I own the Optoma UHZ65 laser projector, which uses the TI DLP66 chip mentioned in the article. I can tell you, in direct comparison to the "native" 4k Sony projectors, you will see more detail with the Optoma! Now, in the real world, there is VERY little difference between "native" and TI's implementation of 4K/UHD. There are other things to consider when making your purchase: The ambient light level in the room, throw distance, ability to put the projector EXACTLY where it needs to be for your screen (the Optoma has VERY limited vertical lens shift, and NO horizontal shift), and your sensitivity to DLP's "Rainbow Effect" (caused by the sequential display of color on a single chip DLP vs. a 3-chip design like Sony, JVC and Epson). Bottom line: You NEED to get your OWN eyes on these projectors and make a decision for yourself, instead of just reading the OPINIONS of others, or trying to decipher spec sheets! I am VERY pleased with the performance of my "pixel shifting" 4k projector, and I would bet even the most jaded out there would be as well, if they saw one in person, properly set up!

drny's picture

I completely agree with the comments by jnemesh.
I myself, have a Epson UB5040 (yes its pixel shifting, not full 4k).
At the current street price of $2,300 it comes amazingly close in image impact to the Sony ES285 at less than half the price.
Of course my current screen is only 100" (sitting only 9' from the screen).
I venture to guess that at 150" the difference in image details would be noticeable.
I will not upgrade to full 4k, until there is a laser projector with at least 3,000 lumens in brightness and the black levels of a JVC-DLA projector, all under $5,000.
Let's hope the market pushes manufacturer to produce such a projector.

jnemesh's picture

Well the UHZ65 I bought for myself comes close! It's $4500 MSRP, has 3000 lumens of brightness, and a laser light engine. While the 2,000,000:1 contrast claimed in it's specs are exaggerated, it's black level comes close to JVC's RS-440 series. While not a "Full 4k" projector, you would see a noticeable increase in sharpness compared to the Epson or JVC projectors. As long as you can live with the limitations of having no horizontal lens shift, this projector should be right up your alley!

drny's picture

UHZ65 does produce a crisp detail 4k image.
Black level and contrast falls short of JVC new line up, but in a completely dark room, the Optoma looks great.
Unfortunately Optoma has opted to eliminate 3D playback from their latest offerings. As such the UHZ65 is not a viable option for me.
Nonetheless it is an excellent Home Theater projector and I am sure you will thoroughly enjoy it for years to come.

jnemesh's picture

Sorry to be the one to tell you, but NO major flat panel manufacturer and several projector manufactures are including 3D. Sales of glasses and media have been declining since enjoy it while you can, because in a couple more years, you wont find the feature on ANY equipment.

drny's picture

3D is definitely on it's way out.
The only TV display that is both 4k and 3D is the Sony Z9D, and this was its final production run.
However, the subject at hand is 4k capable projectors, currently in the market.
Both full 4k, or pixel shift.
Optoma has entered the market with a variety of 4k projectors with Texas Instrument DLP single chip technology.
HD60, HD65 and the UHZ65 (laser light) range from decent to very good in the case of the UHZ65.
The fact is that currently Sony, JVC and Epson sell projectors that are both 4k capable and 3D.
I fully agree that 3D is on its way out, even on projectors, but that is not the case at present.
The projectors that will be in the market in 2020 will likely out perform most current 4k capable projectors, and likely won't be 3D.
Again Optoma UHZ65 is a very good 4k projector, and many will join you in purchasing one. But for those who still enjoy 3D and have now added 4k UHD disc the current options are from Sony, JVC and Epson.

RaleighTiger's picture

As drny said, I wouldn't consider the UHZ65 due to lack of 3D support. This actually seems to be a limitation of the TI chipset, and not Optoma's fault. Some of the newer .47" DLP pixel shifters do support 3D, such as the Benq HT2550 and Optoma UHD51. I am not aware of any of the other 4K projector options dropping 3D support aside from the first generation models based on the TI .67" DLP chip, though I could be missing something.

Movies are still being release theatrically in 3D, and most subsequently on Blu-ray though obviously not in the 4K/UHD format. You may have to purchase a region free version from Amazon UK or other non-US vendor since for some reason some of the studios won't release 3D in the US at all. So yeah... 3D admittedly smells a bit funny but it isn't dead, and if you want to enjoy it a big screen projection system has always been the way to go and little has changed on that side.

Davidthomas's picture

Is the difference between Eshift and native 4k panels analogous to the difference between 1080i and 1080p? In other words are all the original pixels on the screen but just projected half at a time?

HomerTheater's picture

It appears that Blue Planet II may be a real UHD source... Red Dragon is a digital camera and it has a 4K digital intermediate, but the IMDB specs are incomplete... they don't provide the resolution of the Red Dragon camera which could be 4K or 6K if it was a recent model. I'm not sure if the Dragon ever existed with less than 4K resolution. It would be possible to shoot at 3.4K or 2.8K and still have a 4K digital intermediate, albeit with no more than 3.4/2.8K resolution. When you use a UHD disc with less than UHD for the digital intermediate, you aren't using a true UHD source and shifting imaging schemes will have a big advantage over native UHD imagers because the images themselves won't have the resolution of the video display.

HomerTheater's picture

Note that Blue Planet 1 and the 2 Planet Earth series do not appear to have full UHD or 4K images from capture to disc. The images may look very good, but they aren't full-blown UHD/HDR.

HomerTheater's picture

PS. If you haven't seen one of the few REAL UHD discs on a REAL UHD video display, you don't really know what UHD looks like.

Oh, I thought of another "real" UHD disc... The Rocky Mountain Express, a 40-45 minute IMAX documentary about building the Canadian Transcontinental Railroad route through the Selkirk and Rocky Mountains. But not ALL content looks ideal. The aerial shots from what appears to be a helicopter steady-cam appear to be less then full UHD resolution. But images shot with a stationary camera on the train or on the ground can look PHENOMENAL. Some of the shots of the steam locomotive from outside with cameras on tripods are incredible, as are some of the interior shots on the train... the steam engine cab, passenger cars, and the private car at the back of the train.

HomerTheater's picture

I posted a fairly detailed explanation of why so many people are having trouble seeing differences between pixel shift projectors and projectors with native 4K imagers. I'm going to keep this one much shorter... even though I type fast, there are limits! First, the ONLY SOURCE that is acceptable for evaluation of different types of projector are UHD discs that have REAL UHD resolution. Very few discs do. You can find tech specs at (find the Tech Specs section, then click link to full specifications). To be a REAL UHD/HDR source, the images have to be shot with digital cinema cameras having 4K or higher resolution and 4K (or maybe higher some day) digital intermediate. Very few discs qualify. The ones I know of are Passengers (but limited content to mostly inside space ship with a couple of star field scenes), Smurfs 2 (hard to spend money on, but this combines live action with animated characters so you see NY and Paris among other places with animated characters overlaying "real world" locations) and the other titles mentioned in other posts that may appear before this one. Anyway, since most UHD/HDR movie discs come from movies with 2K digital intermediates, pixel shift projectors can look very similar to native UHD projectors because the resolution simply does not exist on the disc to differentiate HD+ resolution from real UHD/HDR images. Pixel shift is a red herring... the gaps between pixels are incredibly small. Shifting pixels diagonally by 1/2 a pixel really isn't a lot different from a 1080 imager showing half the UHD pixels in one frame flash and the other half of the pixels in a second frame flash. With no diagonal shift, the pixels will land on top of each other so the resolution is 1080p no matter whether you are showing 1080p Frame A and 1080p Frame B or if you use a UHD imager to display 2K content. Shifting the pixels really accomplishes little because the spaces between pixels are so darn small, shifting pixels is REALLY not a whole lot different than 2 1080 frames without shifted pixels. The comparison mentioned in this thread where an Optoma projector was claimed to look as good as a Sony projector with native UHD imagers... not remotely possible in my experience with Sony projectors from $10,000 to $60,000. I have not seen one of the Sony $5000 native 4K projectors yet. This was the gist of the original post. AND another point... the lens in the projector is HUGE. I'm looking at projector right now that's in the $5000-$10,000 price range... when I turned this projector on, my first comment to myself was "This projector's lens isn't very good." So it did not look like a native 4K projector. Would other people notice? Not if they were relying on UHD discs that really have 2K resolution instead of REAL 4K resolution in the digital intermediate. So... both the digital camera and the digital intermediate have to be 4K or higher in order for the disc to be useful in revealing differences between displays that achieve their UHD status in different ways than using real UHD or 4K imagers.

HomerTheater's picture

The only discs I've seen with digital camera capture at 4K or higher and digital intermediate of 4K or higher are:
Passengers - but most of the movie takes place inside a space ship so it's not too varied in content
Smurfs 2 - difficult to spend money on this title, but it combines live action in NY and Paris with animated characters interacting with real actors.
MAYBE - Dunkirk, but I have to see it first, shot on super 70 film with a 4K digital intermediate. Unfortunately film grain looks HORRIBLE in UHD making older movies shot on film and released on UHD disc look like there's NEVER anything really sharp on the screen... at least that's what happens when the source film was 35mm. The super 70 film used for Dunkirk MAY make enough of a difference that it looks good on disc, but I don't know yet. There may be other tiles (and I mentioned a couple above), but there certainly aren't many.

HomerTheater's picture

It is LITERALLY because most movie theaters have perforated screens. The SMPTE did a study in a movie theater in LA a number of years ago. They sourced footage mastered in both 2K and 4K then played the 2 shots side by side (butterflied on screen so half the image you saw during the test was 2K DI and the other half was 4K DI. When viewed with conventional perforated acoustically transparent projection screens, those participating (SMPTE members), could see no difference between the 2K and 4K digital intermediates so most studios just kept using 2K for digital intermediates. Only Sony (and affiliated brands like Columbia and Screen Gems) switched over to 4K DIs exclusively. Lionsgate has been running about 50-50 when it comes to 2K and 4K digital intermediates. But aside from IMAX, there just aren't many other "real" UHD resolution discs out thee. Note that the IMAX features shot on film, even though the negative size is huge, they don't look as good in UHD/HDR as the newest IMAX features shot with 4K or higher-res digital cameras. For example, the Butterflies feature is decidedly softer than The Rocky Mountain Express images shot with stationary cameras on the train or on the ground (aerial shots from a helicopter appear to be somewhat lower-res). Back to the SMPTE trial of 2K and 4K digital intermediates in a movie theater... after noting that the perforated screen wiped out 100% of the advantage of UHD or 4K resolution, SMPTE moved a "solid" projection screen into the path (no perforations) and everyone attending could immediately see the improvement in UHD/4K images. This trial "proved" that UHD is better and easily visible to the audience, but the perforations in the projection screens remove 100% of the resolution improvement, leaving you with only HDR to make the images look better. For cinemas to make images as good as what we can see at home with native UHD/4K displays, they will HAVE to change to solid projection screens without perforations. And that may never happen now. With "display walls" being available in very large sizes, UHD and HDR may end up killing projection all together when cinemas change over to light emitting flat panel displays without a projector at all. I can also tell you this... Sony's Z9D is the best-looking UHD/HDR video display I've seen to date. It's even better than Sony's $60,000 projector and I've seen the 65" version of this display on sale for as little as $3500. That Optoma projector mentioned earlier? It's maximum light output was a bit less than 200 nits. The Sony Z9D produced 2000 nits and make UHD/HDR look CRAZY good, even better than Sony's OLED A1E if you ask me (which I also saw being sold for $3500 in 65" size last December). It is difficult to describe how much better images look on an HDR display that can reach 2000 nits. If you put a projector capable of 2000 nits in your room, you'd be able to read a book by the light... projection just gets impractical when it is that bright. This makes projection seem to be living on borrowed time.