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MillimeterHands-on HVX
Feb 1, 2006 11:15 PM, By Barry Braverman
A first-look review of the Panasonic HVX200, video’s latest quantum leap.
Advanced heat sinks in the HVX200 help dissipate the heat and reduce noise in the deeper shadows. Placing a hand atop the lens housing should induce a warm and reassuring feeling. It means the camera is performing and dissipating heat as it should.
The numbers game
Low-light performance in the HVX200 appears to be about 1.5 stops better than the HDV cameras I have tested. The reason is the (apparently) lower-density chipset used in the HVX. Larger pixels mean greater light sensitivity, just as larger film grains lead to higher film speed. In a 1/3in. chipset (actually 6mm), real estate is exceedingly tight. Cramming smaller and smaller pixels onto a tiny chip works against good low-light performance — a matter of importance particularly to small-format video shooters.
Panasonic refuses to state the native pixel density of the new HVX200 CCD. That's a gutsy move on the company's part, as many folks will automatically deduce a sinister motive.
The HVX200 accommodates two P2 cards of 8GB each for a total runtime of 40 minutes at 720p24n (Native mode). The card that is not immediately in use for recording can be offloaded to a laptop, dedicated Panasonic P2 Store, or generic FireWire or USB 2.0 hard drive.
In fact, Panasonic faced a fundamental trade-off when designing its new 16:9 imager. That's because the highest resolution possible for a CCD is not always desirable; everyone would almost certainly perceive as too dark a 1/3in. imager with 2 million pixels. Still, marketers love to focus on numbers, like the clock speed of PCs and the pointless but impressive sounding “700X digital zoom” emblazoned on the side of some consumer camcorders. Professionals tend to know better. But the tendency of shooters, especially many novices, to judge cameras (and everything else) on the basis of numbers alone is a real and ongoing danger.
Suffice it to say that the CCD is an analog device. The silicon crystals embedded in it output a stream of electrons in direct proportion to the amount of light striking its surface. This analog electron stream is then digitally sampled and processed, raising the real issue: how precisely these operations are performed.
In the HVX200, the analog signal from the imager is sampled (incredibly) at 1080p60 4:4:4 RGB. With 524,288 possible values to choose from in the initial processing, the camera's DSP is bound to find one very close to reality when assigning a value to a sample. It also means regardless of the recorded video format — and there are 81 available options — the camera cache is crunching a huge amount of data, which is then parsed to meet the desired scanning mode, resolution, and frame rate. This is one smart camera.
The non-interchangeable Leica Dicomar zoom fitted to the HVX200 performs much better than most low-cost interchangeable lenses. This is because the camera’s imager block physically compensates to maintain optimal lens performance at all times. The shifting imager allows for extraordinarily close focus—virtually up to the front element of the lens.
Video camera mode
The HVX200 is really two cameras in one, and shooters must understand the difference to derive maximum benefit. As a video camera, the HVX applies the VariCam model to output 60p-converted video. Thus when shooting 1080i24p, for example, the HVX will output 60fps by applying a 2:3 pulldown. To be clear, the HVX200 in Video Camera mode captures scenes as we're accustomed to in SD, at 1080i60 (30P over 60i, 24P over 60i, and 24PA over 60i). The 24PA (“Advanced”) mode popularized in the DVX works identically in the HVX200, utilizing a 2:3:3:2 conversion of 60fps 1080i and 480i video streams. The NLE removes the invalid frames during capture to restore the original 24p frame rate. I was able to accomplish this smoothly, capturing 1080i24PA footage into Final Cut Pro — a process that went just as efficiently in the DVX.
Whether shooting 1080i or 720p (30P over 60P and 24P over 60P) in Video Camera mode, the maximum runtime on a P2 card is the same — about one minute per gigabyte. The benefit of Video Camera mode is that the camera outputs a valid DVCPRO HD stream via FireWire to an external VCR or hard drive like the FireStore FS-100, the upcoming CitiDISK HD, or Specialized Communications' CinePorter, thus allowing for a much longer record time. Currently these external drives do not support recording in P2 Native Film mode, a functionality that is still in development. Suffice it to say that certain functions like time lapse, pre-record (up to seven seconds), loop record, and Slow Shutter are available only in the Video Camera setting.
