Panasonic GH1 Flash
Panasonic GH1 Flash
The Panasonic GH1's built-in flash has a guide number rating of 36 feet (11 meters) at ISO 100, translating to a range of about 9 feet at ISO 100 with an f/4 lens or 6.2 feet at f/5.8. That's a little weaker than most digital SLRs, which are typically rated at 12 or 13 meters. The Panasonic GH1's flash is released manually by sliding the Flash Open lever toward the front. 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 nuisance.
When open, the flash doesn't extend very high, so at wide angle even the smallest Micro Four Thirds lens casts a shadow when the lens hood is attached. As you can see from our test results below, it almost clears the 14-140mm kit lens at wide angle without the lens hood in our standard test shots, though you will run into shadows at times. The Panasonic GH1 has a dedicated AF assist LED, and unlike Panasonic's earlier SLR, the L10, the GH1's built-in flash can cannot be used as an auxiliary AF assist, probably because focusing speeds are not quite fast enough. The GH1's flash is disabled by pressing down until it clicks shut.
The 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 doesn't appear to be wireless flash support, as offered on competing Olympus Four-Thirds SLRs.
The Panasonic GH1 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-GH1 also has a dedicated hot shoe, for mounting external flash units, like Panasonic's DMW-FL360. Olympus flash units such as the FL-50, FL-36, FL-20 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 GH1'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
A moderately powerful flash, but uneven coverage. Slightly higher than average positive exposure compensation required. To take advantage of the Panasonic GH1's 140mm (280mm equivalent) maximum focal length, you'll definitely want to pick up an external flash.
|Normal Flash, +1.0 EV||Slow-Sync Mode, Default|
Coverage. Flash coverage is rather uneven at wide angle, and the built-flash is no match for the 140mm focal length, producing a very dark coverage shot at full telephoto. From the ISO 100 series shots below, we can see coverage is better at telephoto, but still somewhat uneven. The length of the kit lens also casts a shadow at wide angle.
Exposure. Indoors under incandescent background lighting, the Panasonic GH1's flash performed quite well, requiring just slightly more than average positive exposure compensation of +1.0 EV for a bright image. The camera's slow-sync flash mode required no compensation, though the longer shutter time results in a warmer cast from the ambient background lighting.
ISO 100 Range. Flash power remains fairly strong to about 12 feet at wide angle. After that, it drops off, but also varies in brightness (15 feet is brighter than 14 feet). At telephoto, the flash starts out a bit dim at our shortest distance of 6 feet but brightness doesn't drop off significantly until about 9 feet, gradually getting dimmer from there.
|Manufacturer-Specified Flash Range|
Manufacturer-Specified Flash Test. Panasonic rates the GH1's flash with a GN of 11 meters at ISO 100. That works out to about 9 feet at an aperture of f/4 and 6.2 feet at an aperture of f/5.8. In the shots above, the DMC-GH1 seems to as Panasonic says it will, providing reasonably bright exposures at the rated distances, however, as we saw in the flash range series above, the exposures with our test target are a bit dim.
Note: Our standard test method for flash range uses a fixed setting of ISO 100, to provide a fair basis of comparison between cameras. With the above test, we're also looking at whether their stated specification rings true.