Maximise your production flexibility with Sony 1080i HDV

Announced in September 2003, HDV offers High Definition recording on a standard DV tape. It is an entry-level HD format designed to appeal to the same market as the phenomenally popular DV/DVCAM formats.

How many video formats are defined in the HDV standard?
The HDV format offers a choice of interlaced or progressive recording, both of which use the same tape speed and track width as standard DV but are otherwise quite distinct.

1080i (interlaced) has a resolution of 1440 x 1080 recorded in an MPEG-2 PES (Packetized Elementary Stream) at approximately 25Mbps - the same bitrate as DV. Two frame rates are supported natively, 50i and 60i, for European and US markets respectively.

720p (progressive) has a resolution of 1280 x 720 recorded using an MPEG-2 Transport Stream at approximately 19Mbps. Four frame rates are supported - 60p and 30p for the US market and 50p and 25p for Europe. It’s important to note, however, that at the time of writing no camcorder supports true 60p or 50p tape recording on the HDV format.

Why doesn’t Sony support all formats?

It’s far more cost-effective to optimise a camera system for a progressive or interlaced operation, particularly at the entry-level where price competition is exceptionally sharp. Simply put, an optimised system offers more performance at a lower cost. Power consumption is also critical in a compact camera, so again a simpler chip has significant advantages compared to a more complex one.

Why did Sony choose 1080i rather than 720p?
1080i offers the best balance of performance for the widest possible range of HDV applications:

1080i resolution delivers the ‘Wow Factor’
High Definition needs to be immediately and obviously superior to the Standard Definition picture quality most people are used to. The diagram below helps illustrate the huge difference between the two formats, based on 1080 and 720 vertical lines. This is difference is particularly obvious in the European market where television audiences are used to the 576 vertical interlaced resolution of PAL

50fps means Production Flexibility

While 24fps is famously associated with motion film production, the vast majority of today’s video content is produced and distributed at either 50i or 60i. A higher frame rate means a smoother, more natural look and is virtually essential for fast-moving events, such as sports, where a slower frame rate such as 25fps would result in a choppy, unnatural look. Sony believes 720 at 25fps is a less than ideal compromise as it offers neither the ‘wow factor’ of true 1080 HD nor the smooth update expected of standard TV programming such as news, sports etc. and is therefore only really suitable for ‘film-type’ applications, although even there the lack of 1080 resolution limits professional usage.

1080i & the ‘film look’

For applications where the ‘film look’ is desirable on HDV, Sony 1080i offers two distinct alternatives;