Panasonic Lumix DMC-ZS20: Performance

PERFORMANCE
The Panasonic Lumix ZS20 has that big zoom lens packed into a slim, easily portable compact digital body, but what other performance goodies has Panasonic managed to squeeze in there as well? We're going to Disneyland to find out.

Shooting Performance
It takes just under 2 seconds for the ZS20 to present a shooting screen at power up and I was able to get off a first shot in about 2.5 seconds - single shot-to- shot times ran about 2 seconds. The camera can zip off 10 full resolution images in about a second with a burst mode that applies focus and exposure from the first shot to all subsequent shots in the series - there's also a 5 fps shooting rate that provides for continuous autofocus and can manage approximately 15 shots before the buffer slows the rate. The write time for the 10 shot burst approached 7 seconds. These figures were obtained with a class 10 (30 mb/sec) 16GB SDHC memory card. Switching to an SDHC UHS-1 16gb card (95 mb/sec) did not impact single or burst shooting or write times.

AF Acquisition (press-to-capture, no pre-focus)

Continuous Shooting

*Note: Continuous shooting framerates are based on the camera's fastest full-resolution JPEG continuous shooting mode, using the fastest media type available (300x CF, SDHC, etc.). "Frames" notes the number of captures recorded per burst before the camera stops/slows to clear the buffer.

Shutter lag performance is good, coming in at the 0.01 second figure that characterizes the better performers in the compact digital camera field. Autofocus acquisition time is likewise speedy, coming in at 0.16 seconds in our studio measurements. The camera is similarly quick in the field and although AF acquisition time predictably slowed a bit in dim light the ZS20 proved to be a nicely responsive compact digital in these areas. There is an autofocus assist lamp for dim conditions.

The ZS20 features optical image stabilization, to be specific what Panasonic terms "power optical image stabilization," or "power O.I.S." for short. One major concern with any camera shooting longer telephoto focal lengths is that camera shake can impact image quality and the longer the lens, the more difficult it is to keep from introducing camera shake since the relatively narrow area of view of the longer lenses is much less forgiving of the slightest movement. With its zoom lens reaching out to the 480mm telephoto plateau, the ZS20 would seem a prime candidate for supplemental support in the form of tripod, monopod or some other device.

The traditional rule of thumb for shooting handheld in the era before stabilized cameras or lenses was that your shutter speed should be at least the reciprocal of the focal length you're shooting at - in the case of the ZS20 at 480mm you'd like to have shutter speed of 1/500th of a second.

If additional camera support is a viable option for your shooting by all means employ it. But I found the power O.I.S. system on the ZS20 did an admirable job of helping with camera shake towards the telephoto end of the zoom lens. If you're shooting handheld you need to lock in the firmest possible hold and make smooth full pushes on the shutter, but this combined with power O.I.S. can give you very good prospects of minimizing camera shake, at least under better lighting conditions that allow for higher shutter speeds.

Panasonic rates the flash on the ZS20 as having a range of 2 to 16 feet at wide-angle and 3.3 to 8.5 feet at telephoto with ISO set to auto. Flash recycle times ran about 5.25 seconds at telephoto with what appeared to be a full discharge shot (aperture priority, ISO 100) and about 3 seconds under brighter conditions using intelligent auto.

The ZS20 features a built-in GPS function that goes a bit beyond the simple latitude - longitude tagging of images:
"Map data can be installed onto the LUMIX ZS20 via a bundled DVD, giving the camera detailed worldwide maps of major regions on a scale of 1/25,000 or more precise. A user can copy the map data of a designated city to an SDXC/SDHC/SD Memory Card and get quick geographic information to know their location and if any landmarks are located nearby. More than one million landmarks and 82 countries/regions are covered in the bundled DVD map.

Geo-tagged images are automatically sorted and can be played back along a map so that users can literally trace their photographic journey. Many GPS cameras show only the latitude and longitude of where a photo is taken, but the LUMIX ZS20 shows the name of the Country/Region, State/Prov./County, County/Township, City/Town/Village and Landmark - all of which is saved in the EXIF data."

Panasonic goes on to mention that the GPS function may not work in China or in the border areas of countries surrounding China.

The ZS20 battery is rated for approximately 260 shots, so one or two backups for all-day shooting sessions would be a prudent investment. A search of the Panasonic USA accessories bin didn't turn up any remote battery chargers that appeared to accommodate the ZS20 battery, which must be charged in the camera. The camera must also be switched off to the charge the battery, so there's no opportunity to post process images or do other work with the camera if you need to charge the battery.

Lens Performance
The Leica DC Vario-Elmar lens on the ZS20 has a good pedigree, but is a bit on the slow side with maximum apertures of f/3.3 and f/6.4 at wide-angle and telephoto, respectively - f/8 is the minimum at both ends of the zoom. At wide-angle the lens shows fairly uniform sharpness across the frame, with edges and corners being just a bit softer. Telephoto is likewise better in the center and looks a bit softer than wide-angle on the edges and corners as well.

There's just a hint of barrel distortion at the wide-angle end and an equally slight bit of pincushion distortion at telephoto. Chromic aberration (purple fringing) is present at both ends of the lens, but less so at telephoto. Enlargements of 200% or more are generally required for the defect to become easily noticeable throughout the focal range.