Cello c42t71dvb-3d

2D performance

It takes some patience to get this screen looking as good as it can. Set up is cranky and there's not a great deal of resident tech to help out.

The Picture menu offers four viewing modes: Standard, Soft, User and Dynamic. It's only possible to change the picture parameters in the User preset. Unfortunately, the TV has a short term memory and tends to forget what you've set.

The Sharpness gauge should be restricted to a 0 or 1 – anything else adds glowing white edge enhancement - but wander around the menus after you've set it, and unwanted edge emphasis awaits your return. The numerical gauge number may not have changed but the enhancement returns none the less; you have to nudge the settings to restore your chosen balance.

The CCFL backlight doesn't allow for deep blacks; at best it manages a moody dark grey. Contrast isn't particularly high either. Blu-ray test footage of Tokyo at night confirms a low level of noise amid the engulfing grey, although it is certainly possible to extract shadow detail. You can apply various levels of noise suppression, which keeps a lid on general picture fizz.

The set's colour fidelity is a tad gung-ho. Unless you like reds verging on luminous orange, you'll need to dial down the colour range. Take the slider to around 31 for more authentic hues. Also adjustable is colour temperature, with individual levels of R, G and B control.

After calibration, challenging HD test footage of glinting brass instruments and lustrous violins becomes pleasingly believable, while reds that verged on atomic are brought back to healthier levels.

It should be noted though that the picture is over-scanned by default, and none of the settings offer a 1:1 mode. Consequently, edge-image is lost behind the bezel.

The screen itself does not feature any fast framerate technology to improve motion clarity. We measured moving resolution at around 600 lines at 6.5ppf (pixels per frame). This means that motion blur is unavoidable, making this TV a poor choice for sports fans and gamers.

A test pattern which comprises scrolling English and Japanese text confirmed this clarity loss. At 6.5 ppf, text is bleary at 100-, 50- and 30 per cent luminance; clarity deteriorates further at 2.5 ppf.

On the plus side, at least viewers don't need to worry about the 'soap opera' sheen created by high frame rate processing, wherein even blockbusters look like they were shot on cheap camcorders.

While the screen's Freeview tuner limits over the air definition, the TV looks considerably better with 1080p Blu-ray content.

3D performance

Cello is the third set manufacturer we've seen to use LG 's FPR (Film pattern retarder) panel technology (after LG itself and Toshiba). It won't be the last.

Passive Polarising technology makes for an interesting alternative to Active Shutter. Rather than put the onus on expensive shuttering glasses to create 3D, filtering is done by the screen itself, allowing inexpensive polarising glasses to be used.

In terms of depth, the 3D works well. However the Passive approach ensures that the vertical resolution of incoming 3D signals is effectively halved. This is evidenced by jaggy edges on diagonals and curved surfaces. However, those intending to use 3D primarily to pacify small 'uns are unlikely to be bothered.

Similarly, brightness and colour are largely undiminished by the glasses supplied. Cello's over-large, lightweight specs may not be the height of fashion, but are comfortable to wear. The set is compatible with other inexpensive polarising eyeware from RealD and others.

One characteristic of Passive 3D which does impact general viewing is the very narrow field of view. As long as you're face-on to the screen, double imaging (aka crosstalk) is not a significant issue. However, move vertically off-axis by as little 15 degrees and the 3D picture will quite quickly fall apart. This means that care needs to be taken when it comes to TV placement. Do not position this set high, because if you're watching at an angle, the 3D effect will be compromised.

Curiously, we also noted some double imaging evident at the left and right edges of the screen itself. Parallax can be altered by a 3D Scene adjuster, variable between 1-10.

The TV automatically adjusts to frame sequential 3D from Blu-ray. However, side-by-side 3D content seemed to cause the set problems. Pronounced double-imaging made homebrew 3D footage created by AVCHD camcorders largely unwatchable.

Rather helpfully the manual warns against watching 3D 'on an open staircase or balcony with cables or other articles that might cause you to stumble.'

It goes on to advise that 'this product is designed to make you feel personally in the scene on the film, some true-to-life 3D videos might make you take evasive action, resulting in stumbling or falling which may lead to personal injuries.'

Well, there's nothing like being optimistic. Confidentially, the 3D effect is not really that convincing.

According to the manual there's also a 2D-to-3D conversion. However, when engaged this makes no attempt to dimensionalise flat footage. Instead, the screen image flips into a weird banded mode that looks like nothing you'd want to watch, with or without stereoscopic eyeware.