Two days after unveiling what it said was the smallest high-definition video camera in the world, Matsushita Electric Industrial Co. (Panasonic) took the wraps off an even smaller camcorder, the HDC-SD7, on Wednesday.

The HDC-SD7 camcorder measures just 52 millimetres by 110mm by 87mm, giving it a volume of 330 cubic centimetres - that's smaller than the 375cc of the HDC-SD5 that got its international launch on Monday. It weighs 350 grams with the battery and memory card against 400 grams for the SD5.

Design-wise, the two cameras look very different: the SD7 is taller than it is wide or long so has the appearance of being held vertically while the SD5 is longer than it is tall or deep so is held horizontally.

They have almost identical technical specifications. Both pack 3CCD (charge coupled device) sensors behind a 10x zoom lens and have a 2.7-inch widescreen LCD (liquid crystal display) monitor.

One of the secrets to their small size is the use of an SD memory card as a recording medium. The electronics and socket needed for a flash card takes up much less space than a DVD or hard-disk drive and thus contribute to the size and weight savings over other high-def models.

Both record full HD (1,920 pixel by 1,080 pixel) MPEG4 AVC/H.264 video at a range of quality levels. At the average 9Mbps (bits per second) rate, a 4GB SD card can hold up to 60 minutes of video, said Panasonic.

The cameras will both cost around ¥140,000 when they go on sale in Japan. The SD5 will launch in August and the SD7, which will only be available in Japan, will hit the shelves in September.