Test Drive: Panasonic AG-HMC70, Part 2

Back again with the $2,100 (street) shoulder-mount Panasonic AG-HMC70. In the previous installment, I evaluated features and usability. Here, I''ll look at quality and summarize the comparison of the HMC70 with the $1,900 Sony HVR-HD1000U HDV camcorder, the HMC70''s closest competitor—which I reviewed here—and the Canon XH A1.

I compared the Panasonic camera with the HD1000 and the XH A1, which has produced the best quality that I''ve seen in laboratory tests—albeit at twice the price of either other camcorder and lacking the shoulder mount form factor. Briefly, although the Sony only has one CMOS imaging device, it has 2,280,000 effective video pixels—which is more than sufficient for 1920x1080 capture and processing, which the camera does before subsampling down and storing the video in 1440x1080i HDV resolution. In contrast, the Canon has three CCDs, each with 1,670,000 pixels—which is sufficient for full resolution, 1440x1080 HDV capture.

As you undoubtedly recall from poring over the first segment, the HMC70 has three CCDs, each with a gross pixel count of 520,000 pixels, and it relies upon a technique called pixel shifting to produce sufficient pixels for HD capture. I was eager to see how this would translate to quality in my tests.

I use three standard tests for comparing camcorders, all from DSC Labs. Briefly, from a workflow perspective, I shot the video and captured in Apple Final Cut Pro, which converted the AVCHD files into ProRes format, and then I imported the ProRes 422 files into the Mac version of Adobe Premiere Pro to create frame grabs, which I compared to previous frame grabs from the other two cameras.

Figure 1. DSC Labs CamBook Multiburst resolution test.
Click here for a larger image.

The first test is the CamBook Multiburst test pattern, which is shown in Figure 1. Briefly, this chart measures the camcorder''s ability to preserve horizontal and vertical detail by presenting multiple boxes with increasingly dense lines in both the vertical and horizontal axis. Resolution is “preserved” when you can clearly see both the lines and the white spaces in the box.

If you click to view the full-resolution figure, you''ll make several observations. First, the XH A1 still presents the clearest image, with 700 lines clearly legible both horizontally and vertically. The Sony is slightly clearer at 600 lines of vertical resolution (illustrated by the 600 lines horizontal box), while the Panasonic is slightly clearer with less moiré pattern at 500 lines of horizontal resolution (illustrated by the 500 box with vertical lines).

Figure 2. The ChromaDuMonde chart measuring both detail and color accuracy.
Click here for a larger image.

Next up is the ChromaDuMonde chart, which measures both resolution and color accuracy (Figure 2). In terms of resolution, the XH A1 again clearly wins, while the Sony seems better at resolving horizontal detail—as evidenced by the vertical lines circled on the upper left of all charts.

Holding the chart up to my big-screen HP LP3065 monitor to compare color, I noticed that the Panasonic''s color were more accurate than either other camcorder—particularly in the greenish box on the upper left hand side and the brownish box on the lower left. It''s hard to draw any conclusion from this, however, because I color-corrected all videos, and the differences are subtle.

Figure 3. The fabulous CamBelles chart seems to indicate that the Panasonic AG-HMC70 has more accurate skin tones than the Sony HVR-HD1000U.
Click here for a larger image.

To get a better handle on the color issue, I shot the fabulous CamBelles chart shown in Figure 3. Here, it looked like the HMC70 matched skin tones more accurately than the HD1000, which often looked a touch brassier and a slightly noisier.

Alhough the XH A1 was the clear winner in all detail-oriented tests (as you would expect), the Sony and Panasonic camcorders were neck and neck. While the Sony''s big-pixel CMOS imager seemed to provide an advantage in terms of detail preservation, the Panasonic''s three CCDs seemed to produce better color. That said, few viewers would notice the difference in either still-frame or realtime playback tests.

Figure 4. The demolition derby winner, circling with his checkered flag.
Click here for a larger image.

Real-world tests were quite positive. For example, I produced a Blu-ray Disc of my daughter''s graduation in Pinnacle Studio 12, and the video looked crisp and clear on my 36in. JVC HD television. Definite hit with the graduate and her mom.

I did notice one difference between HDV and AVCHD video: The former tends to get blocky when stressed, while the latter seems to just lose detail—which you can see in the background in Figure 4, a screengrab of the demolition derby winner taking his victory lap. As an aside, I''ll guess that this was the only demolition derby in history ever won by a pink minivan, driven by a brawny mechanic obviously in touch with his feminine side. Ah, but that''s the beauty of the sport—you just ever know what to expect. Plus, unlike NASCAR, you get to make right hand and left hand turns, and even go backwards!

Anyway, while HDV''s blockiness and AVCHD''s loss of detail are both evident in still pictures, AVCHD''s softer feel looks better in realtime. That said, with a maximum data rate of 14Mbps, not to mention low pixel count CCDs, it feels like manufacturers such as Sony and Panasonic have been making AVCHD fight with one hand tied behind its back.

While I''m confident that at the same data rate, AVCHD will preserve more quality than the MPEG-2 based HDV, I''m not convinced that at 14Mbps, AVCHD produces the same quality as HDV at 25Mbps. Fortunately, we won''t have to wait much longer to test this theory; most vendors, including Panasonic, have AVCHD camcorders with much greater pixel counts and up to 24Mbps data rates on the way.

For today, how does the AG-HMC70 stack up against Sony''s HVR-HD1000U? From a quality perspective, they''re about the same—a slight edge in detail to the Sony, courtesy of its higher pixel count CMOS imager, with the Panasonic''s three CCDs delivering slightly better color quality.

With two XLR connectors, the HMC70 has much better audio connectivity, while the HD1000 has slightly better usability, with the single configurable ring making the unit more usable under changing exposure conditions. On the other hand, in a fast-paced, run-and-gun shooting environment, the HMC70''s flash memory-based AVCHD workflow is vastly superior to the HD1000''s tape-based HDV workflow—unless you''re an Adobe producer, of course, in which case there is no real workflow for AVCHD. At least for now.