HDTV

Toshiba 55ZL2 4K LCD 3D Display

ARTICLE INDEX

Introduction to the Toshiba 55ZL2

When Toshiba announced the idea of a glasses-free 3D display, I was less than enthusiastic. I have been seeing lenslet based 3D glassless displays for a few years (mostly in the B2B and Digital signage spaces) and they were far from ready for consumer prime time.

TOSHIBA 55ZL2 SPECIFICATIONS

  • Design: 55" LCD Display
  • Illumination Source: LED
  • Native Resolution: 3840 x 2160
  • Active Motion & Resolution 800M
  • 3D Active
  • 2D-3D
  • Connections: 4 x HDMI (1.4), 2 x USB
  • DLNA
  • WiFi Ready (dongle)
  • Audyssey EQ
  • Personal TV (camera sensor)
  • Toshiba Apps
  • PVR
  • Toshiba
  • SECRETS Tags: 4K, 3D, HDTVs

While these technologies have continually improved, no manufacturer was brave enough to talk about consumer versions until Toshiba did so. The first version of the 55ZL2 was first shown off privately at IFA Berlin in September 2011, a later version in January, 2012 at the CES in Las Vegas. However, it wasn't until Toshiba had a private showing in Cologne, Germany, for the International press that I got to see the real deal.

The Regza 55ZL2 has many features, most of which we've seen before in other Toshiba displays, but it has two specific features that are a world's first: this is the first consumer mass produced display with 4K resolution (3840X2160, four times Full HD), and it is the first mass produced display with Glasses Free 3D (GF3D as Toshiba refers to it).

During previous presentations, Toshiba showed off the unit without many of the features in place. Most importantly, what they added is face tracking system capable of adjusting the 3D to the eyes of those who are actually watching the display.

To me, what was even more interesting was the fact that a single button push can turn off 3D altogether. The ability of this screen to turn into a real 4K display was mind boggling to me and the real appeal to this display.

In this review, I will primarily focus on the 3D and 4K capabilities of the display.


Sound, Interface, Remote of the Toshiba 55ZL2

Toshiba really didn't invest much in the remote; it is virtually identical to the other remotes for its high-end displays. The remote is plastic and tube shaped and has a sliding metallic looking plastic cover that can hide the more advanced buttons. I'm still unclear about the design – the remote is too long and the purpose of the sliding portion is clearly a design aesthetic, as it serves no real purpose. The buttons are not phosphorous and so some light is required to make heads or tails of them. Many important functions are placed in hard to reach spots – this display really needed a remote revamp, in my opinion.

The user interface is graphical and nice looking. It is fairly simple and more traditional than its LG or Samsung counterparts. Not all features are so easy to get to, but generally speaking, the user experience is positive and you can generally find what you're looking for relatively quickly.

The screen design is clean and simple. The display has a thinner bezel than any previous Toshiba screen I've seen, and the design lines are simple and clean. This is not a flashy design – it lets the contents of the screen speak for itself. Without the logo, I would have pegged it for a South Korean design more than a Japanese one.

As this is a very thin screen, some compromises with sound always have to be made. In this case, Toshiba placed the speakers in the back of the display, which means they need to bounce off the back wall to get to the viewer. While this works OK in most cases, this can detract from the overall sound quality.

Inputs are pretty standard. I liked the fact that the unit has two sets of USB connections, 4 HDMI connections, audio, satellite and OTA tuners. The unit does come with a built-in WiFi receiver and of course works with an Ethernet port (which I prefer).

Although the display does have an anti-reflective layer, the front glass does reflect quite a bit, so I would recommend against placing it in an area where it would reflect an open window.

While other high end Toshiba models now offer face recognition-based personalization (mostly picture and audio settings), these are present in the ZL2 but only manually – the face detection system here is dedicated to the 3D portion of the display.

Since the ZL2 has so many different parts, it requires seven cell (CEVO) cores to run all of its features. That is by far the most CPU-intensive display I have ever seen. One strange thing was the fact that it took 28 seconds for the TV to "cold boot" (if it was turned on recently, this time cuts down to a reasonable 10 seconds).


The Toshiba 55ZL2 3D without Glasses

I'll try and refrain from being overly technical. The idea behind Glasses-Free 3D is fairly simple and uses what we call the "lenticular" technique that you see in 3D postcards and bookmarks. A new layer is placed over the LCD panel called a "lenslet layer". This layer is made up of miniature lenses, which are placed very exactly so that a single lens is dedicated for each triplet of the 24,883,200 sub-pixels (which means that this layer contains approximately 8.3 million lenses). Each block of 3X3 lenses is identical and repeats over and over.

Each lens forms its own light column. That means that light from a specific pixel can be shown as long as you're in the space where it is active. If you move to the left or to the right of that viewing area, that pixel will appear to be turned off (in ideal conditions). Immediately after that pixel's view area, comes (with a small overlap) the pixel underneath it or next to it. This pattern is designed so that when one light field (or view) is active, its neighbors are not but when one ends, the next one immediately begins. This is repeated, until nine separate views are formed. Each view is approximately 6.3cm in width, and since eight usable views are made (the 9th one turns out to be unusable) you get 50.4cm for each viewing zone. The lenses are made so that the entire cycle is repeated - i.e., that very same pixel starts working again if you're exactly 50.4 cm away from the first point where you saw it.

Now, what is actually playing on each of these nine pixels? That's where the camera and face detection comes into the mix. The camera and appointed CEVO core determines which person's face is closest to the center of the screen. Since it has essentially two images to show that person, it will create them in such a way that the pixels pointing at them will show that picture. It will also try to optimize it so that adjoining pixels will also show that picture.

Once more people are detected; they'll have to move their heads to join in the fun. There are a few ways to adjust the tracking. The first tool is a picture-in-picture screen showing what the display is actually seeing from its point of view. There are a few green "slots" signifying the ideal positions for people to be seated. Faces in good spots will have dark blue rectangles in them (if you watch "Person of interest", this concept will be familiar to you.). People in areas that are "not good for 3D" are marked with incomplete light blue squares.

The next technique is location circles. When this feature is turned on, you can see three circles on the screen – on the left, center, and right top parts of the screen. These are very light and unobtrusive. I kept forgetting to turn them off during viewing and actually like when they are there. When you're seeing a good 3D image, you should only see 3 circles. However, if you're not in a good seating position, these will turn into arrows pointing in the direction where you should be located – forward/back (or angled), and left/right.

Pressing the tracking button (buried at the bottom of the remote) gets the system to rediscover where viewers are located. If people move, this is probably a good thing to try.

There is also a manual override option that lets you see a test pattern on screen and bypass the camera's detection. This is a cool feature, but probably less useable for normal people that move around.

Seating positions are critically important. Toshiba recommends seating 2.2m away from the TV and has very specific angular recommendations regarding vertical and horizontal angles where 3D works well. Go outside of these parameters and you will see blurry images rather than proper 3D.

Note that the 3D being produced is 720P per eye. I was actually expecting some dark areas (similar to what passive 3D displays produce – similar to CRT scan lines) but the image is complete – but the lower resolution and the equivalent of crosstalk are the main drawbacks here.

Crosstalk in active/passive 3D occurs when information from one eye appears inadvertently in the other. In this case, it occurs when one view "leaks" into another – causing your to see a fuzzy image or one comprised of several views.

3D Glasses-free is still far from perfect. The need to stay upright and steady really caught me off guard. I'm used to slouching on my couch and this is not the right TV to try and do that with. Some portions of the screen seemed too blurry to me and the 3D effect is much more subtle than I'm used to with active or passive 3D screens. Also, when using the 2D to 3D conversion, I felt that the display was way too subtle in the conversion – it took something quite dramatic (like an object against a far away background) to notice the 3D effect.

However, the effect is much more pronounced when viewing a Blu-ray than with Side-by-Side or converted content. Avatar 3D on Blu-ray, or Monsters vs. Aliens looked much better than converted content. The resolution loss was quite clear, though.

My feeling was that this technology is still rough around the edges and will require much more fine tuning before it can really become mainstream.


The Toshiba 55ZL2 4K – OMG

As an industry insider, it's not often I get blindsided by display technology. This is one of these rare instances where I was truly blown away. I remember the first time I saw proper 1920 x 1080p content on a projector over a decade ago at an AVSforum party at CES. That was the second where I decided this was more than a hobby for me.

The effect of seeing a real 4K image from a 4K source in my house was a similar mind blowing experience.

Toshiba was kind enough to send me a 4K demo player. This is far from any production box. It is a simple box running a short sequence of 4K video in a loop. It is noisy and klunky and connects to the display using a proprietary "service" cable.

The images were the kind you'd expect to see at a trade show demo. They were so realistic you could walk over and grab a flower, touch the model (and get arrested), or walk into the city. The difference between what we've been thinking of as "HD" and this "Ultra HD" was phenomenal. You could see the difference from 3m away or you could watch the screen from a few inches away. The image is truly amazing.

4K content is coming with LG, Sony, and Toshiba trying to get the format out the door, using Blu-ray as early as 2013. I'm waiting with breathless anticipation. Count me in.

In my view, this is the killer feature of this screen. Forget glasses-free 3D. 4K is way more impressive.


The HD and Blu-ray Toshiba 55ZL2

The interesting part, of course, is how Toshiba achieves this feat, and it is no simple matter. The lenslet layer is very delicate, and somehow, Toshiba has found a way to turn it off completely.

The patterns caused by this disabling of the lenslet layer leave the pixels as circular in shape while in 2D mode.. I am not really sure Toshiba achieves this, but it's nothing short of magical.

Since most people do not have 4K content, we're going to stick with 1080p content coming from Blu-ray. The Resolution+ system upscales that content to the 4K screen. While this is somewhat of a compromise, you can definitely tell the screen is sharper than any other screen without it introducing significant halo artifacts. The pixels are simply that much sharper – so the effect is quite dramatic.

One of my favorites Blu-ray's is The Fifth Element in its remastered form. It is sharp, has a noticeable grain pattern which gives it a nice edge. I have been testing with the Leeloo birth scene ever since the CUE bug was shown by Spears & Munsil in the DVD days…

I could not see any artifacts resulting from the upscale from 1080p to 4K. The scars on the scientist's face were detailed and perfect.

Forget what you know about HDTV….

Inglorious Basterds had the same immersive effect. The sharpness was amazing.

The first signs of trouble were with Sin City, which has an amazing range of contrast. The nature of this movie forces a display to show its real contrast abilities and the ZL2 kept the backlight on for far too long – causing blacks to be much grayer than I would have hoped.

Gone are the days of backlit local dimmed LED displays, and it's too bad – this is where it would have really paid off.

Broadcast HDTV was far fuzzier than Blu-ray. The difference was much more noticeable than on a 1080p screen.


The Media and Network Streaming Toshiba 55ZL2

I won't go too deep into these features, but suffice to say that the display supports DLNA as both a renderer (you can send stuff to it to be rendered) and as a client. Both options worked partially with the 55ZL2. As a client, the display was quite picky regarding which server software it would work with. When trying to pull content from Synology NAS, which has a great DLNA service – it simply failed to play any video content (photos and music worked fine). My Microsoft shared content worked OK (But media player service does not support any interesting content formats), while Twonky worked partially. Since these are all functional DLNA servers, I can only conclude this is another DLNA compatibility failure.

Content did play fine using USB ports.

For some reason, the display is really fond of my iTunesU content, as it played it fine even when no other video content would play using DLNA.


The Toshiba 55ZL2 Toshiba Places

Again, I won't go too deep into Toshiba's Smart TV offerings. Suffice it to say that there are quite a few options here. These include YouTube, daily motion style video playback, concerts, music and other Over the Top services.

I wouldn't go switching out my cable box, Roku or Apple TV for one of these just quite yet.

On the social side, Twitter and Facebook apps are available. Still not sure who the target audience is – I'm not aware of anyone in my family who is interested in plastering their social lives on the living room TV.

It should be noted that there is room for 4 accounts that you can use to identify yourself – for receiving messages, and working with Twitter and Facebook. You can switch between them using the quick menu (which is loaded with not too many features to be called "quick"). Since anyone can go into your Twitter account, if you're worried about your social traffic, I would advise against logging on through the display. There is no password.

By the way, it looks like the Opera browser powers the entire Toshiba Places environment. It looks relatively quick and video streaming quality is pretty good for this type of service.


The Toshiba 55ZL2 Bench Test Measurements

The color gamut seems to be slightly off from the recommended REC709 measurements. I would expect this from a new type of panel, in fact it is surprising they got as far as they did.

Toshiba has a few interesting picture modes. Autoview adjusts the backlight based on the surrounding light and the content itself (bright vs. dark). This works quite well, but I did notice fluctuations as it changed.

Hollywood day and night are supposed to be ISF style calibration levels. It gets 6228 degrees Kelvin and a high 2.7 Gamma at Hollywood night mode.

A setting of static gamma of +10 moves us to 2.24 – a much more agreeable gamma setting. You will likely want a slightly higher value than that (which means a static gamma setting of between +5 and+10 depending on your room and preferences).

Color temperature is pretty stable. The Hollywood day/night settings do not get enough red, and green seems to be unusually bright.

The 55ZL2 has a Hollywood Pro mode. With an additional tristimulus USB sensor (I did not get one, so could not verify), the display apparently can calibrate its own gamma, gray level, and primary colors!

Each of these options can also be done manually. This is one of the most extensive CMS systems I've seen so far.

If you have the USB calibration sensor, you can choose an automatic Gamma calibration – you specify what gamma you want (2.4 is the default), and it scans through its own IRE test patterns and fixes both gamma and white balance automatically. Alternatively, you can white balance the display to D65 using 10 or 2 points, using either built in IRE window patterns or your own content.

Finally, primary colors can be adjusted manually or automatically (using the sensor). Secondary colors do not have their own controls.

For those who like the built in settings, Color temperature level 3 comes closest to the 6500K target.

One serious drawback to the 55ZL2 is its backlight. The display uses edge mounted LEDs that reach 400 cd/m2 (less than the 700 cd/m2 that the manufacturer boasts about). The screen is very thin, which leaves a very thin area for the backlight diffuser. This means that the backlights areas are visible when a uniform IRE100 is displayed. The display reaches a 71% uniformity level – something that really needs addressing by Toshiba.

The panel's contrast ratio was measured at 7500:1, I checked this twice. This is much higher than I expected, particularly given this high resolution panel. It looks like the panel Toshiba commissioned (apparently manufactured by LG) is top notch. The panel has no angular artifacts – no serious discoloration or loss of light at side angles or up/down angles that I could see.

The display's spectral footprint is pretty standard:

The artifact testing worked remarkably well, save for a few interesting tidbits. First, when sharpness is set to 0, there is still some image processing at play. To turn off sharpness artifacts, I recommend to keep the sharpness value slightly below at around -10.

The S&M jaggie test went remarkably well, almost no jaggies except for nearly horizontal angles.

One strange test that failed was the chroma burst which failed only on RGB mode. Luma burst failed on all 3 modes.

Another failure was the vertical mixed content pattern: rolling credits at the end of the movie flickered, while the background video stuttered in trying to cope.

BTB, WTW and pulldown testing worked fine. Most modern displays fail to show 1080p on a moving zone pattern with their intermediate frame algorithm turned on. The 55ZL2 did show such artifacts when the Active Vision 800Hz was set to "Smooth" mode. However, in "Standard" mode (which means it does create intermediate frames, just not as many), there were no such patterns.

It's hard to judge the upscaling capabilities of the 55ZL2. Since it has to upscale to four times as many pixels, there's really not enough of a reference point to know if it does a good job at it. I would say that it does seem as sharp or sharper than what typical 1080p screens do these days. I would expect that when 4K video processors come out, we'll be blown away again by how much external processors can improve on scaling.


Conclusions about the Toshiba 55ZL2

This is a well built, nicely designed display. It has a top notch panel, with less than mediocre backlight and a mediocre remote. Although its claim to fame is 3D without glasses, I was far more impressed with its 4K capabilities (particularly with a 4K source), and with its CMS and video processing.

This would be one ideal LED display if Toshiba improved backlight issues (better diffusion, or a 512 zone local dimming option like in the ZL1). The 55ZL2 is less of a "Smart TV" in the traditional sense than what LG or Samsung are offering, but in terms of image quality amongst LED displays, it stands apart from the crowd.

The recommended price for the 55ZL2 in the UK is around 7000GBP (around 10,000USD).

The price is expected to come down when the unit does arrive in the US soon.

See Ofer LaOr's blog at www.hometheater.co.il for additional discussions about the Toshiba 55ZL2 3D LCD Display.