Pentax K10D Flash

Coverage and Range
Good flash performance, with good coverage and intensity. An average amount of positive exposure compensation was required.

Flash coverage was slightly uneven at wide angle, with falloff in the corners of the frame. However, at telephoto, coverage is much more even. Indoors, under incandescent background lighting, the Pentax K10D's flash performed quite well, requiring +1.0 EV exposure compensation, which is about average. There's a slight orange color cast to the background from the incandescent light source, but overall color is pretty good. With the camera's slow-sync flash mode, results are also quite bright at the default exposure, though the longer shutter time results in a much stronger orange cast.

The Pentax K10D's flash was bright and powerful at wide angle, with excellent intensity all the way to about 12 feet at ISO 100 at 18mm, with slight decreases in exposure from that point onward. Its range at maximum telephoto is somewhat limited by the small f/5.6 maximum aperture of the kit lens, producing a slightly dim result at 6 feet and the exposure started falling off somewhere around 8 or 9 feet.

Our standard test method for flash range uses a fixed setting of ISO 100, to provide a fair basis of comparison between cameras. The Pentax K10D's guide number is 11 meters at ISO 100, which translates to about 10.3 feet at f/3.5. In the shot above, the K10D seems to perform exactly as Pentax says it will, producing good exposures at the rated distances with its ISO set to 100.