Panasonic GF1 Flash
The Panasonic GF1's built-in flash has a guide number rating of 20 feet (6 meters) at ISO 100. That's a lot weaker than most digital SLRs, which are typically rated at 12 or 13 meters. The GF1's closest rival, the Olympus E-P1, doesn't include a popup flash at all, though, and even a relatively weak flash might prove useful for those times when you don't have an external flash strobe at hand.
The Panasonic GF1's flash is released manually by pushing the Flash Open button on the camera's rear panel. Raising the flash enables it, though it can be defeated using a menu selection. 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 GF1's flash is disabled by pressing down until it clicks shut.
The Panasonic GF1'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 the Record menu, and available settings vary depending on exposure mode. A Digital Red-Eye Reduction feature is offered, which when enabled, will attempt to remove red-eye after the photo is taken, via post-processing. A second curtain synchronization mode is also offered. 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 GF1.
The Panasonic GF1 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 DMC-GF1 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 GF1's user manual, though.)
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
Modest flash power, though good coverage with the 20mm lens. Higher than average positive exposure compensation required.
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| 20mm | |
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| Normal Flash, +1.0 EV | Slow-Sync Mode, Default |
Coverage. Flash coverage was pretty good with the 20mm lens (some of the fall-off is due to vignetting in the lens itself), but keep in mind that's not very wide on a Micro Four Thirds camera (40mm equivalent). Given the amount of falloff at 20mm, we think the flash won't have very even coverage at more typical wide angles such as 14mm (28mm eq.)
Exposure. Indoors under incandescent background lighting, the Panasonic GF1's flash struggled with our standard flash portrait test scene, resulting in a dim exposure, even when the flash exposure compensation was increased to +1.0 EV. (For whatever reason, the flash exposure adjustment had very little effect.) The camera's slow-sync flash mode required no compensation, though the longer shutter time resulted in a much warmer cast from the ambient background lighting.
| Manufacturer-Specified Flash Range |
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| 20mm kit lens, f/2.8 |
 7.0 feet ISO 100 |
Manufacturer-Specified Flash Range Test. Panasonic rates the GF1's flash with a Guide Number of 6 meters (19.7 feet) at ISO 100. That works out to about 7 feet at an aperture of f/2.8. In the shot above, the DMC-GF1 performed as Panasonic says it will, providing a well exposed image at the rated distance.
Note: This test uses manufacturer-specified camera settings, at the range the company claims for the camera, to assess the validity of the specific claims.
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