HD movies | Standard HD versus Full HD

Today's digital cameras can shoot video as well as stills, making conventional camcorders redundant for many people. And nearly all high-end cameras can now shoot HD video, which means a massive leap forward in picture quality.

Cameras with full HD movies 

There are currently two HD formats in use:

• Standard HD (1280 x 720 pixels)
• Full HD (1920 x 1080 pixels)

Both formats use the 16:9 'widescreen' ratio used by the latest TVs. Full HD offers the best picture quality, but standard HD shot by a good camera is still more than adequate for most casual users and even professional movie makers.

This diagram shows the relative sizes of full HD, standard HD and the 640 x 480 pixel resolution of the movie modes on older compact digital cameras (roughly equivalent to standard TV definition).

Full HD may not always offer the advantage in definition which the numbers suggest, though. This is because some full HD devices use 'interlacing' to achieve this definition. Here, two 'fields' of 540 pixels resolution are interwoven to give the impression of greater resolution.

Interlaced video is indicated by an 'i' suffix. It's common to see HDTV or camcorders described as offering '1080i' resolution, for example.

The alternative is 'progressive' video, where each frame is drawn in its entirety. This gives better results, but is not always possible at the higher resolution. Generally, standard definition devices produce progressive video, which is therefore described as '720p'.

As the hardware and technology improves, there is a move towards progressive video even with full HD, and this would be described as 1080p.

HD cameras shoot video in one of two main formats:

Motion JPEG/AVI/QuickTime

These files can be copied across from the camera's memory card and double-clicked for playback on a computer, uploaded to YouTube or imported into video editing software. It's as simple as that, and much more straightforward than the old days, where the camera had to be connected to the computer so that video could be 'captured' (recorded) in real time. The main disadvantage is file size. You need a big memory card and/or plenty of spare hard disk space on your computer.

AVCHD

This is a file format developed by Panasonic and Sony. It uses a more sophisticated compression system than the Motion JPEG format to produce movie files which take up half the storage space with little or no loss in quality. The disadvantage is that they use a complicated directory/folder structure on the memory card and can't simply be dragged across and double-clicked like Motion JPEG files. You need AVCHD-compatible software to transfer, import and edit these files, though the latest video-editing programs do provide this.

HD movie formats

Today's digital cameras can shoot video as well as stills, making conventional camcorders redundant for many people. And nearly all high-end cameras can now shoot HD video, which means a massive leap forward in picture quality.

There are currently two HD formats in use:

• Standard HD (1280 x 720 pixels)

• Full HD (1920 x 1080 pixels)

Both formats use the 16:9 'widescreen' ratio used by the latest TVs. Full HD offers the best picture quality, but standard HD shot by a good camera is still more than adequate for most casual users and even professional movie makers.

This diagram shows the relative sizes of full HD, standard HD and the 640 x 480 pixel resolution of the movie modes on older compact digital cameras (roughly equivalent to standard TV definition).

Full HD may not always offer the advantage in definition which the numbers suggest, though. This is because some full HD devices use 'interlacing' to achieve this definition. Here, two 'fields' of 540 pixels resolution are interwoven to give the impression of greater resolution.

Interlaced video is indicated by an 'i' suffix. It's common to see HDTV or camcorders described as offering '1080i' resolution, for example.

The alternative is 'progressive' video, where each frame is drawn in its entirety. This gives better results, but is not always possible at the higher resolution. Generally, standard definition devices produce progressive video, which is therefore described as '720p'.

As the hardware and technology improves, there is a move towards progressive video even with full HD, and this would be described as 1080p.

HD cameras shoot video in one of two main formats:

Motion JPEG/AVI/QuickTime

These files can be copied across from the camera's memory card and double-clicked for playback on a computer, uploaded to YouTube or imported into video editing software. It's as simple as that, and much more straightforward than the old days, where the camera had to be connected to the computer so that video could be 'captured' (recorded) in real time. The main disadvantage is file size. You need a big memory card and/or plenty of spare hard disk space on your computer.

AVCHD

This is a file format developed by Panasonic and Sony. It uses a more sophisticated compression system than the Motion JPEG format to produce movie files which take up half the storage space with little or no loss in quality. The disadvantage is that they use a complicated directory/folder structure on the memory card and can't simply be dragged across and double-clicked like Motion JPEG files. You need AVCHD-compatible software to transfer, import and edit these files, though the latest video-editing programs do provide this.

PAL and NTSC | Less important with the arrival of HD

PAL and NTSC are the two most commonly-used broadcast formats around the world. PAL is used in the UK, NTSC in the US. Digital cameras and camcorders need to produce the right output for the TV they're connected to. The distinction between PAL and NTSC is likely to become less relevant, though, as digital and high-definition broadcasting take over from conventional analogue transmissions – PAL and NTSC are old fashioned 'standard def' technologies.

It's not just broadcast TV which will be affected. It look as if digital devices will increasingly connect to high-definition TVs via digital HDMI cables (below) rather than old-fashioned analogue PAL/NTSC connectors.

Digital cameras and high-definition camcorders now shoot in a variety of digital formats, but you will still need to select PAL or NTSC if you produce DVDs for playback on domestic TVs and DVD players. The movie editing/DVD software will then carry out the necessary conversions.

PAL and NTSC do use different frame rates (25fps and 30fps respectively). Movie editing software can adjust the frame rate when you export, so that if your device captures footage at 30fps (most do), the software can adjust this to 25fps on export using complex resampling techniques. The results won't be quite as good, however, as if you'd shot at 25fps in the first place.

This is reflected in the latest generation of digital SLRs with movie modes. Where compacts almost always shoot at 30fps, these SLRs typically shoot at 25fps (Panasonic GH1) or offer a choice between 25fps and 30fps (Canon EOS 7D).