Sony HDR-HC7 Camcorder Reviewby John NeelyPublished on Mar 19, 2007 2:00 PM
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Compression (7.0)
The Sony HC7 uses HDV compression, a flavor of MPEG-2 with a fixed data rate of 25Mbps – the same as standard definition DV compression. HDV is a terrific format in terms of video resolution, though it suffers a bit when capturing fast motion due to its use of I frames. In a 1080i camcorder like the HC7, this means that only one in fifteen frames is a full-frame picture, while the intervening frames are compressed in relation to each I frame – a technique known as interframe compression. By contrast, every frame in a DV stream is a complete picture, so renders motion better despite its much lower resolution. DV also uses a superior 4:2:2 color space while HDV encodes in a truncated 4:2:0 color space. The Sony HDR-HC7 is one of the first high definition camcorders to support the new xvYCC color specification. It can be turned on or off in the Camera Set Menu, and should produce video with a better dynamic range than prior HDV implementations.
Despite the inherent weaknesses of HDV, it is still the best high definition format available on the consumer camcorder market, and most consumers find its stunning resolution trumps the superior motion handling of DV. AVCHD, a new HD format that uses H.264 compression was introduced in 2006 and compresses video even more aggressively than HDV. Our tests of Sony’s HDR-UX1 and HDR-SR1 last fall show that while AVCHD video is very sharp, it suffers from grain and artifacts much more than HDV compression. The wildcard in the high definition arena is JVC’s upcoming MPEG Transfer Stream codec, which will appear for the first time in the company’s Everio HD7 HDD-based camcorder. MPEG Transport Stream compresses video at up to 30Mbps, and may rival or even outclass HDV compression. We’ll weigh in on this as soon as we can get a production HD7 into our labs.
Media (6.0)
Like other HDV camcorders, the Sony HDR-HC7 records to MiniDV cassettes which are an inexpensive and readily available format, and the same format used by standard definition DV camcorders. MiniDV cassettes have a run time of 60 minutes in SP mode, but can hold up to 90 minutes of lower-quality LP video. Unlike the DVD, SDHC memory card, and HDD formats, MiniDV tapes cannot be searched randomly. Searching for footage is a linear process, and transferring clips to a PC from tape is a real-time process. For anyone serious about the quality of their video, HDV recorded to MiniDV cassette remains the best option available. To date, consumer non-linear video formats do not support the highest-quality video compression codices for high definition (HDV) and standard definition (DV).
Editing (7.0)
The Sony HDR-HC7 records both HDV and standard definition DV video to MiniDV tapes, and both formats are now broadly supported by consumer and professional NLEs (non-linear editors) like Apple iMovie and Final Cut Pro, Avid Liquid and DV Express Pro, and Adobe Premiere. Moving transferring footage to a PC or Mac for editing is done via the included IEEE 1394 (otherwise known as FireWire, and branded as “i.LINK” by Sony) cable, so your PC will need an appropriate adapter, while all Macs are IEEE 1394 compatible.
Due to its higher compression rate, editing HDV taxes a computer’s processor more than DV, but any newer computer with at least 512MB of installed RAM (and preferably 1GB) and an HDV-compatible NLE should be able to handle 1080i footage.
The HC7 ships with Picture Motion Browser ver. 2.0 which includes rudimentary editing software and accompanying drivers for Windows computers.
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