Amazon launches 4K service

A selection of shows and feature films in ultra-high definition are now available to watch and download for any customer with a compatible television set.

Ultra-high definition, or 4K, offers four times the resolution of HD and is slowly but surely inching towards the mainstream and into consumers' living rooms. It would move more quickly if more people owned UHD TV sets -- but for that to happen, more native content would need to be available.

In an attempt to address this issue, Amazon has become the latest company to formally commit to the new format and is offering its Prime customers -- ie those who pay a yearly subscription for extra services -- free access to a number of Amazon Original TV shows, in 4K.

As well as TV shows, Amazon has added an initial four Sony Pictures Entertainment films -- 'Crouching Tiger, Hidden Dragon,' 'Funny Girl,' 'Hitch' and 'Philadelphia' -- to its Prime Instant Video service.

However, any Amazon customer with a UHD TV that supports the company's Instant Video App will be able to watch the 4K-filmed 'Tony Bennett & Lady Gaga: Cheek to Cheek LIVE!' for free and anyone, Prime Member or not, will also be able to purchase and download a range of feature films in the format. Prices start at $19.99 and titles include 'American Hustle,' 'Captain Phillips,' 'Elysium,' 'Godzilla,' 'Moneyball,' 'The Monuments Men' and 'The Amazing Spider-Man.'

Even though 4K is still a developing technology, Amazon is a little late to the party. It had promised that its 4K service would be live by October. This year has already seen Netflix launch a 4K streaming service (and charge a premium for it) and YouTube and now Vimeo support video clips shot in the format.