Panasonic Lumix DMC-GX1
Panasonic GX1 Flash
The Panasonic GX1's built-in flash has a Guide Number rating of 7.6 meters (24.9 feet) at ISO 160. With the 14-42mm kit lens, that translates to a range of 7.1 feet at f/3.5, or 4.5 feet at f/5.6. The GX1 doesn't offer an ISO 100 setting, but since most cameras don't provide an ISO 160 guide number, it's worth noting that its flash offers a strength equivalent to 6 meters at ISO 100. That's much weaker than most digital SLRs, which are typically rated at 12 or 13 meters, but not unusual for a compact system camera.
The Panasonic GX1's flash is released by pressing the Flash Open open button on the rear of the camera. Raising the flash enables it. It never pops up automatically like some models, which can be good or bad, depending on your point of view. A novice would probably appreciate an auto-pop-up flash, but someone with experience might think it a nuisance.
When open, the flash doesn't extend very high, so at wide angle longer Micro Four Thirds lenses could cast a shadow when the lens hood is attached. The Panasonic GX1's flash is disabled by pressing down until it clicks shut.
The Panasonic GX1's built-in flash has seven modes: Auto, Auto with Red-Eye Reduction, Forced On, Forced On with Red-Eye Reduction, Slow Sync, Slow Sync with Red-Eye Reduction, and Forced Off. Flash modes are changed via either the Quick menu, or an option on Page 2 of the Record menu, and available settings vary depending on exposure mode. The flash is forced off when closed. A Digital Red-Eye Reduction feature is also offered, which when enabled, will attempt to remove red-eye after the photo is taken, via post-processing. For slow-sync exposures, both first and second curtain synchronization modes are provided. X-Sync (the maximum shutter speed with the flash enabled) is 1/160 second, a bit below average these days, and there is no mention of a higher-speed FP (focal plane) mode. There's also no wireless flash support in the Panasonic GX1.
The Panasonic GX1 allows you to adjust flash and ambient exposure independently of each other, by providing flash exposure compensation between -2 and +2 EV in one-third EV increments. Flash exposure bracketing is not supported, and there is no manual flash mode where output level can be set as a percentage of full power.
Like an SLR, the Panasonic GX1 also has a dedicated hot shoe for mounting external flash units, like Panasonic's DMW-FL500, FL360, and FL220. Olympus flash units such as the FL-50, FL-36, FL-20, and FL-14 should also work, and non-dedicated units can also be used provided they have a compatible trigger voltage and polarity. (Panasonic does not seem to mention the trigger voltage or polarity in the GX1's user manual, though they do warn against using an external flash with "high-voltage" or reverse polarity.)
The advantages of a good external flash are many: more power for increased range, faster recycle times, longer battery life, reduced red-eye, auto zoom to match coverage to the current focal length, and the ability to adjust the tilt and swivel of the head to allow light from the flash to be bounced off nearby surfaces such as a ceiling, for a diffuse effect. Most external flash units have a more powerful AF assist illuminator built-in than the one on the body, and other useful features such as modeling flash are common on higher end models.
Flash Test Results
Coverage and Range
A small, weak flash with uneven coverage at wide angle. Above average positive exposure compensation required.
|14mm, f/3.5, ISO 160||42mm, f/5.6, ISO 640|
|Normal Flash, ISO 160
|Slow-Sync Flash, ISO 160
Coverage. Flash coverage is rather uneven at wide-angle, leaving the corners of our flash target image darker at 14mm, thought that's not unusual. Some of the corner shading can also attributable to the lens itself. Coverage is more uniform at full telephoto (42mm).
Exposure. Indoors under incandescent background lighting, the Panasonic GX1's flash underexposed our indoor portrait scene at ISO 160, despite the +1.0 EV flash exposure compensation used. (An average of +0.7 EV is normally needed for this shot.) You'll likely need to boost ISO (or enable Auto ISO) for typical indoor shots. The camera's slow-sync flash mode required no compensation, though the longer shutter time results in a much warmer cast from the ambient background lighting.
ISO 160 Range. At 14mm wide-angle, flash exposure was bright out to 7 feet, which agrees with Panasonic's GN rating. Brightness decreased gradually with distance from there. At full telephoto, flash exposures started out quite dim at 6 feet (as expected), and brightness fell off rapidly from there. Keep in mind the GX1's base ISO is 160, so flash range is not directly comparable to cameras that have a base ISO of 100. (We may change this test to use ISO 200 going forward, as a number of cameras don't offer ISO 100.)
|Manufacturer-Specified Flash Range|
Auto ISO 1000
Auto ISO 800
Manufacturer-Specified Flash Range Test. Panasonic specifies a flash range of 22.3 feet at wide-angle, and 13.8 feet at full telephoto with the kit lens, with ISO set to Auto. As you can see above, the Panasonic GX1 produced a good flash exposure at the rated distance at wide-angle (the flash target is just slightly overexposed), but results at 42mm were quite dim. What's odd here is using the GN to calculate the theoretical flash range at ISO 800 results in 9.9 feet at telephoto (f/5.6), not 13.8 feet, so we're not surprised the telephoto shot is underexposed. Our standard test method for flash range uses either a fixed setting of ISO 100 (ISO 160 for the GX1), to provide a fair basis of comparison between cameras. We've now also begun shooting two shots using the manufacturer-specified camera settings, at the range the company claims for the camera (at Auto ISO if so specified), to assess the validity of the specific claims.
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Note: For details, test results, and analysis of the many tests done with this camera, please click on the tabs at the beginning of the review or below.