Toshiba 55ZL1 Cevo

Before we look at the 55ZL1 Cevo in detail, let's take a look at the television's origins.  It was originally called the Cell TV because of the powerful processor that can simultaneously handle eight different HD streams or around forty SD streams.  That sort of performance is popular in some of Toshiba's other markets, but it isn't necessarily what European viewers need. 

The manufacturer went back to the drawing board and switched the Cell TV processor for the less powerful Cevo Engine.  It might only be able to handle a single video stream at once, but it's better suited to everyday viewing.

Build Quality and Design

The ZL1 Cevo that we're testing has a 55'' PVA display (the LTA550HQ08 from Samsung-Sony) and a 512-zone Full LED backlighting system which relies on three thousand individual LEDs.  Like the vast majority of high-end TVs, the display itself sits behind a glossy panel, and while that might look good when it's switched off, reflections from ambient light sources are irritatingly common.  You'll need to be careful to keep it out of the way of a window or else invest in some heavy curtains.

A more welcome feature of high-end TVs is support for 3D.  Toshiba has plumped for a system that uses active glasses, and has also added 2D-to-3D conversion, and claims that the power of the Cevo Engine processor means it does a better job than other TVs that offer this.  Other noteworthy features include support for DLNA 1.5, the Active Vision M800 HD motion interpolation filter with a 200 Hz mode and backlight sweeping, and finally a 500 GB external hard drive for recording TV programmes.

This wouldn't be a Toshiba TV without the Toshiba Places platform, which uses either the Ethernet port of WiFi to provide access to a wide range of VOD services via a clean, user-friendly interface.  Most impressively, it's surprisingly fast.

Alongside a decent selection of video inputs--four HDMI ports, and one each of VGA, SCART, composite and component video--Toshiba's latest flagship also has two TV tuners and two USB ports.  The latter can be used to access media stored on external devices formatted using NTFS or FAT 32.  Strangely, though the media player uses the same interface as the external Toshiba Places media centre, the TV itself seems to have a different video decoder.  During our tests, we were disappointed to find that there was only support for MTS files encoded using AVC, which really isn't that much.

Toshiba has also designed an automatic calibration system that relies on an optional extra hardware device which it claims allows it to offer the same perfectly natural picture quality as a Hollywood studio would expect.  We didn't get a chance to test it, but we think it would be useful for another reason: both monitors and TVs gradually deteriorate over time, so an occasional recalibration will allow viewers to enjoy a consistent picture.




Unfortunately, we have to conclude this first part of the test on a negative note.  Given how much Toshiba is asking for the ZL1, we were expecting it to have an absolutely perfect finish, but that just wasn't the case.  Those silver sections you can see aren't the aluminium or stainless steel we'd hoped for, but cheap painted plastic.  A television in this price range deserves much better. 

Image Quality

Toshiba has improved on the quality of its earlier televisions when showing 2D content, with decent results even using the factory settings, which is something of a rarity.  Things get even better if you switch to 'Hollywood Pro' mode, activate the dynamic backlighting and set the brightness to 5.


Once that's done, the colour reproduction is accurate.  We found an average deltaE of 2.5, representing a very narrow gap between the colours requested by the video source and those actually shown on screen.  When this value falls below 3.0, any remaining discrepancies are invisible to the naked eye.


The 512-zone dynamic backlighting system works perfectly, sending the contrast ratio rocketing above 5000:1, with deep blacks of 0.03 cd/m², which is quite simply perfect.

Not everything's perfect, though: we found an average colour temperature of just below 6100 K, instead of the usual 6500 K, and while the viewing angles are wider than on most TVs, but still only received a score of 3.1/5.

During our practical tests, Blu-ray films came a lot closer to perfection, with lovely deep blacks but plenty of detail visible in dark areas of the screen.  There's not much hope for SD content like DVDs or ordinary TV, as even with the powerful Cevo processor, it's hard to get good results on such a huge screen.  That's really not what this TV does best.

The motion interpolation is great too, and video doesn't look like it's been shot on a camcorder as it so often does with this sort of post-processing.  The most demanding viewers might spot a few visual artefacts in long, panning shots or behind fast-moving characters, but it's reassuringly rare.  Watching a Blu-ray disc is a real treat.

Clouding and blooming

As well as producing higher contrast ratios than would otherwise be possible, dynamic backlighting also does away with clouding, a problem caused when light leaks into darker areas of the screen.  As a result, the ZL1 manages to produce a more even picture across the surface of the screen than even a plasma TV.  Blooming, a glowing halo around lighter objects against a dark background, is invisible when you're looking straight at the TV.  It's a little bit more obvious at either side of the screen, but it's still very minimal and tricky to spot.

Ghosting and Input Lag

Responsiveness
Light Background	Dark Background	Average

The Samsung panel that Toshiba has chosen for the ZL1 behaves in the same way as the one found in the Sony HX923.  That makes it one of the most responsive we've ever seen, with an average ghosting time of 8.5 ms.  The downside is a relatively high input lag of 66 ms or four frames, which is enough to put the most avid gamers off.  Nobody else need worry about these results though.

Image Quality: 3D

As we mentioned earlier, Toshiba has chosen active 3D technology for the Cevo.  We started by trying the 2D-to-3D conversion, which the manufacturer claims is more powerful than on some of its rivals.  That's true enough, but it's still far from stunning, and really can't replace genuine 3D content.

We were disappointed by the results with Blu-ray 3D discs, which had noticeable crosstalk despite the presence of that responsive Samsung display.  When it comes to 3D on LCD TVs, Samsung still has a clear advantage, while plasma screens are the choice if you demand absolute perfection.

Here's what we saw through the glasses (Toshiba 55ZL1 above, Sony HX923 below):



Unlike many of its rivals, which sometimes only provide a single pair, or none at all, Toshiba includes two pairs of 3D glasses.  They're not all that comfortable, especially if you're used to the lightweight passive glasses used at the cinema.  Once you're done watching a film, you'll want to give your nose a good rub to get rid of the marks that they'll leave behind.  The good news is that, despite being pretty heavy, the glasses are quite wide, meaning that you can wear them on top of ordinary glasses.

Audio Quality

The ZL1 comes with its own sound bar that slots in between the stand and the bottom of the frame, and obviously enough, the audio quality is much better than it is on televisions with basic built-in speakers.  It's still not perfect though, and could do  with extra power and more bass.  We've given it five stars as it's currently the best available sound on a television, but there's still plenty of work to be done.  If we were judging it on its own against other sound bars, it would only have managed three stars.

Energy Consumption

The ZL1 might have a giant screen, but the same won't be true of your electricity bill.  It's not the best performer in this area, but it still scrapes home with a five-star rating in this section thanks to consumption of 165 W while switched on, which is around half as much as an equivalently-sized plasma.  On standby, it's equally impressive, with consumption of just 1 W.