TechReport (UK)

HD (High Definition) or UHD (Ultra High Definition)?

A number of years ago, the concept of HD (High Definition) TV was launched onto the market.

At that time, only the relatively newly launched Blu-Ray players were able to provide source material that could utilise the higher resolution of the HD TVs (and not necessarily at the ‘Full HD – 1080P – resolution) and these TVs did not include receivers compatible with HDTV broadcasts (even if they were being transmitted at the time, which they were not).

Over the years, most TVs are now able to display source material in ‘Full-HD’ and many TV channels are now broadcast to this standard.

Inevitably, manufacturers now want to offer us ‘more’, so have come up with the UHD (Ultra High Definition) or ‘4K’ standard.

Effectively, this means a picture with 4 x the number of pixels compared with Full-HD (the grid-lines to the right indicate the amount of detail we can actually resolve at the various resolutions):

In the early days of 4K TVs, there was very little source material available – just a few UHD Blu Rays played on very expensive UHD Blu Ray players.

Now there is a good range of material on several streaming TV services (Netflix, Amazon Prime TV) and both Sky (via their Sky Q system) and BT (via their BT Sport UHD channel) offer 4K / UHD channels. The considerable extra bandwidth required for UHD makes terrestrial broadcasting unlikely in the near future, however.

Is it worth going for a UHD TV then?

Well, UHD is fast becoming ‘the norm’ for any of the mid to large screen sizes – only the very lowest end models do not offer this feature, so you may well end up with it even if it is not important to you.

As to whether it is worth it, well in many cases you would have to say probably not. Many people still struggle to determine the difference between normal and HD material, so the step-up to UHD is unlikely to make any perceptible difference to them.

One of the recommendations with UHD is to sit closer to the TV screen in order to be able to fully appreciate those extra pixels – this would, in many cases, be impractical and sitting too close to a TV for extended periods of time could, from past reports, have implications for your eyesight.

There are clearly some types of source material, however, that would benefit from being viewed in UHD as opposed to HD, so from this standpoint as UHD is gradually becoming the norm (and will certainly be on almost all TVs within a few years), it would perhaps be slightly churlish to try to avoid it, if only from the viewpoint of future proofing your viewing experience.

One word of caution – some older (and perhaps several current) model ‘UHD’ TVs are not compatible with the ‘4K’ streaming service provided by Netflix. As Netflix is perhaps the most significant current provider of 4K (UHD) material (streaming services are likely to remain the main way of receiving such material in the future too, as it is difficult to fit many 4K broadcasts into the available capacity), if you are thinking of purchasing a UHD / 4K TV it is essential that you check that it is compatible with this / similar services.

Next: HDR

Back to TV Technology Roundup