Panasonic GF5 Flash

Coverage and Range
A small, weak flash with uneven coverage at wide angle. Above average positive exposure compensation required.

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 GF5's flash underexposed our indoor portrait scene at ISO 200, 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 further (or enable Auto ISO) for typical indoor shots. 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.

ISO 200 Range. At 14mm wide-angle, flash exposure was reasonably bright out to 7 feet, which agrees with Panasonic's GN rating for the built-in flash. Brightness decreased gradually with distance from there. At full telephoto, flash exposures started out quite dim at 6 feet (as expected from the flash rating), and brightness fell off rapidly from there.

Manufacturer-Specified Flash Range Test. Panasonic rates the GF5's flash with a Guide Number (GN) of 6.3 meters at ISO 160. At ISO 1,600, that works out to about 18.8 feet at an aperture of f/3.5, and 11.5 feet at an aperture of f/5.6, the maximum apertures of the 14-42mm kit lens. In the shots above, the Panasonic GF5 produced a dimly exposed target at wide-angle. despite using spot metering mode. However at full telephoto, the target was bright and actually slightly overexposed, so we conclude the flash rating is credible. Our standard test method for flash range uses either a fixed setting of ISO 200, 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.