Sony A58 Flash

Coverage and Range
Excellent flash range, but with narrow and uneven coverage at wide angle. Our standard indoor portrait shot required lower than average exposure compensation.

Coverage. Flash coverage is quite narrow and uneven at wide angle (18mm), leaving very dark corners in our flash coverage test image. Coverage is much more uniform at full telephoto (55mm), with only minor fall-off in the corners. Our telephoto test image has a pinkish tint to it, though (auto white balance was used.)

Exposure. Our Indoor Portrait test scene is bright with only +0.3 EV flash exposure compensation at ISO 200. The average amount of flash exposure compensation required for this scene is +0.7 EV, so the A58's flash system performed better than average here. The camera's Slow-Sync flash mode produced very bright results with no flash exposure compensation, though with a stronger orange cast from the ambient room lighting.

ISO 200 Range. With the 18-55mm kit lens, flash exposures at wide angle started out bright at 6 feet, and actually increased or maintained brightness to 15 feet. While 16 feet isn't quite as bright, it's still well-exposed, so we'll call the range 16 feet at wide angle which is excellent. At full telephoto, flash exposures are bright out to 9 feet, dropping off from there.

Manufacturer Specified Flash Test. The Sony A58's built-in flash unit is rated with a Guide Number of 10 meters or 32.8 feet at ISO 100. That works out to about 9.4 feet at f/3.5 and 5.9 feet at f/5.6, the maximum apertures of the kit zoom lens. In the test shots above taken at those distances, the A58's flash produced bright flash exposures (even slightly overexposed at wide angle), which confirms Sony's flash power rating is credible. Again, note the pinkish cast with auto white balance.

Our standard test method for flash range uses a fixed setting of ISO 200, to provide a fair basis of comparison between cameras. We also shoot two shots using the manufacturer-specified camera settings, at the range the company claims for the camera, to assess the validity of the specific claims.