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The Trouble With Filters

The first thing we paid close attention to was resolution. And it frankly took all of one minute to find ourselves convinced by active 3D’s advantage in this department. This is especially true with 3D Blu-ray content, where active 3D delivers the same pixel-perfect precision you would expect with a 2D HD feed, while the passive set leaves proceedings looking markedly softer and less detailed.

This isn’t actually at all surprising when you think about it. For when you’ve got a filtering film applied to the front of a 1,920 x 1,080 screen that in 3D mode sends half the available resolution to one eye while the other half goes to the other eye, then it seems obvious that you’re effectively only seeing half the resolution of the full HD source. Which arguably makes buying a 3D Blu-ray player a total waste of time.
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Picture showing how passive 3D glasses reduce line resolution


Another problem for the passive screen is that it’s possible to see horizontal line structure in its picture caused by the physical structure of the 3D filters. The impact of this diminishes the further you move away from the screen, but it certainly distracted us on the large 55in screen at even perfectly normal viewing distances.

The black striping effect also seems to have a negative impact on energy consumption, as the passive screen has to work harder to deliver the same luminance levels as ‘stripe-free’ active panels. Our measurements suggested that the passive TV used in our head to head was consuming around 15 per cent more power than Samsung’s active one.

First impressions haven’t been particularly kind to the passive 3D model, and things go from bad to worse the deeper we look. Focusing on contoured edges, for instance, while they look as clean as a whistle on the active 3D set, they’re really quite a mess on the passive set, suffering with quite severe jaggies at steep angles and almost blurring out completely when you get to shallow angles at the bottom of curves. This is another artefact, it seems, of the passive screen’s inevitable filters.
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The black band visible on the passive image here is caused by the way the glasses' polarisers struggle with high frequency lines


Next on our checklist is crosstalk. And here, at least, we expected the passive screen to deliver the goods. But actually, the situation is nowhere near as clear cut as expected. If you’re sat right in front of the passive set then there is marginally less evidence of the dreaded double-ghosting problem than you get with the active set. But our head to head experiments confirmed our findings during our 55D8000 review that Samsung has made huge strides forward with its 2011 3D TVs in combating the crosstalk issue.

Also, disturbingly, crosstalk on the passive set went through the roof if we shifted our viewing position to above or below the screen. And we’re not talking about massive angles here, by any means.

If our heads were as little as 15 degrees - even slightly less - above or below the passive set’s screen, the amount of crosstalk became unbearable. This clearly presents a potentially huge problem for people wanting to, say, mount their TV high - above a fireplace, perhaps. And it’s potentially a serious issue for pubs and clubs, given that many viewers will probably view Sky 3D football matches from a standing rather than sitting position. Samsung’s active 3D set suffered no such vertical angle-related crosstalk issues.

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