Sony HDR-HC7 Camcorder Review
Video Performance*** (10.5)*
The HDR-HC7, as Sony's top truly consumer HDV camcorder (we’re dismissing the HDR-FX7 as a contender in that category), comes equipped with only the best bits and pieces. Most of the top-end Sonys in each format offer a new imager, a 1/2.9" ClearVID CMOS sensor with 3,200,000 gross pixels (2,280,000 effective pixels in 16:9; 1,710,000 effective pixels in 4:3). We really liked what we saw with last year’s 1/3 ClearVID CMOS chips, which have been carried over to most of the second-tier models in each format.
At 3000 lux, the richness of the color was the most obvious characteristic. Sony does their market research, and rarely fails to give the public what they want. Saturated, rather than accurate, colors are preferred by the average camcorder owner, and the HC7 delivers. Our color chip chart looked like a box of crayons. Every color popped with remarkable crispness. The HDR-HC7 offers a Color +/- control, which affects saturation. Turning it up produced a horrid palette, reminiscent of some of Sony’s DVD camcorders from years past. But rolling the saturation down a little did improve the picture, especially if you find the HC7’s natural tendencies too strong.
The picture was also sharp, which is something that you can’t fake. Even against the HD camcorders we’ve seen so far, the HC7 looked very good. There are controls included for increasing and decreasing the sharpening, but we found that a sharpness bump only served to hurt the overall image quality, increasing the amount of haloing along high contrast borders and boosting the general levels of noise.
By comparison, the HDR-HC3, last year’s only consumer HDV from Sony, offered a sharp picture without quite so much saturation. We did, however, remark in that review last year that the saturation was higher than the previous year’s HDR-HC1, which indicates that boosting saturation is a trend. Last year’s HDR-SR1, the camcorder that recorded AVCHD footage to hard drive, offered a slightly duller color palate and more noise; the HDR-UX1 (the DVD version), even more so.
The HDR-HC7, along with the HDR-UX7, offers an X.V.Color shooting mode, which records video in the xvYCC color space. xvYCC has been around for a little while, but like the IEEE1394 cable, Sony is branding it with their own name in an attempt to create an association in the customer’s mind ("wow, those guys invent everything, don’t they?"). The new color space is both wider and deeper than sRGB, reportedly 180% better. Unfortunately, we’re in a difficult position to evaluate this. Only one television from Mitsubishi is currently on the market that can display the xvYCC color space. It was on the show floor at PMA, with a side-by-side sRGB image. At a cursory glance, the image looked more saturated than anything else.
Video Resolution* (18.9)*
We use a DSC Labs CamAlign chart designed to specifically gauge resolution in our camcorders, measured in line widths/picture height. At best, the Sony HDR-HC7 showed approximately 650 lines of vertical resolution and 580 lines of horizontal resolution. This represents a small improvement over last year’s HDR-HC3, but falls a bit short of the Canon HV10.
Sony camcorders with the 1/3" ClearVID CMOS typically performed very well in low light. Imagine our disappointment, albeit unsurprised disappointment, that HDR-HC7 performed so much worse than last year’s HDR-HC3. The reason is simple, but one that we see frequently repeated in cameras and camcorders. The Sony HC3 had a 1/3" CMOS with 2,103,000 pixels; the HC7 has a 1/2.9" CMOS with 3,200,000 pixels. When a manufacturer boosts the number of pixels on the same surface area (or in this case, an infinitesimally larger surface area), those pixels have to shrink. Smaller pixels mean a reduced ability to collect light. This is practically a golden rule of optics (though we've already seen the low-end Canon ZR850 buck that trend). While the overall resolution is increased (and boy, does that look good on the bullet point specs at Best Buy!), low light performance and color performance go down, and noise goes up.
At 60 lux, the HDR-HC7 looked considerably worse than the HC3, which was among the best low light performers of last year. We’re crushed to see Sony sacrificing something as crucial as low light for a boost in resolution. The picture was very grainy, and the colors had been compromised considerably. We ran the test over several times just to make sure we weren’t missing something. Sure enough, the difference in quality is evident. At 15 lux, the HC7 tried valiantly to retain some color, but the noise levels are tremendous.
Update (Feb. 20, 2008):
We came across some unusual results when testing the HC7’s replacement, the HDR-HC9, which prompted us to retest the HC7. It became clear that a human error was made during testing. The Auto Slow Shutter feature, which is meant to be deactivated, was left on. When we retested the HC7 with the Auto Slow Shutter off, the results were interesting. On the whole, having the Auto Slow Shutter turned off hurt the low light score, especially the sensitivity test. The retest showed that the camcorder was able to achieve 50 IRE at only 17 lux. We reconfirmed that previous score of 7 lux could only be achieved with the Auto Slow Shutter on.
However, the color error and noise – recorded at 60 lux – actually improved with Auto Slow Shutter off. The retest scores showed a color error of 11 (versus 11.9 in the original test) and a noise score of 2.52% (versus 3.04% in the original test). Looking at the whole series of results, is appears that the Auto Slow Shutter is beneficial for very low light levels, but at moderate low light, it may be advisable to leave the Auto Slow Shutter off.
These new results substantially widen the gap between the HDR-HC7 and the Canon HV20, the latter winning by a huge margin.
The Sony HDR-HC7 utilizes the company’s Super SteadyShot Image Stabilization system, an OIS (optical image stabilization) to reduce the effects of camcorder shake on the image. OIS systems achieve this through an optical process that does not impact video resolution, often in the form of a gyroscopes built around the lens element. This contrasts with EIS (electronic image stabilization) systems that reduce shake through digital processing. The digital processing found in EIS systems does result in a slight loss of image resolution, and are inferior to OIS.
We tested the Sony HDR-HC7’s OIS system using our camcorder shake emulator. The shake emulator reproduces camcorder shake at different levels of intensity.
We tested the HDR-HC7 at Speed 1, equivalent to the shake produced while holding a camcorder and standing still; and Speed 2, equivalent to the more intense shake of a moving vehicle. The Sony HDR-HC7’s OIS reduced recorded image shake by approximately 75% at Speed 1, and 50% at Speed 2. These calculations were derived by measuring the motion difference between footage shot with OIS off and OIS on.
Wide Angle* (7.6)*
We measure the field of view of camcorders in their native recording mode - 16:9 for high definition camcorders and 4:3 for standard definition camcorders. The zoom is set to its widest angle, image stabilization is turned off, and we view the full video frame on an external monitor derive a field of view measurement. The HC7’s maximum field of view was 38 degrees.