Sony A58 review
Sony A58 review - Image Quality
Colour and white balance
The Sony A58's Auto White Balance performs pretty consistently, delivering pleasing results and natural skin tones under a range of lighting conditions. There's also a host of presets (Daylight, Shade, Cloudy, Incandescent, Fluorescent (Warm White), Fluorescent (Cool White), Fluorescent (Day White), Fluorescent (Daylight), Flash, Colour Temperature Set, Custom) to dabble with as well, though for most conditions, the AWB copes admirably.
The Sony A58 features a choice of Multi segment, Centre-weighted or Spot metering modes, calculated via the camera's 1200-zone evaluative metering system. In our tests, the Multi segment metering performed well, exposing well for most scenes, though on occasion in bright situations is did have a slightly tendency to under-expose the shot, requiring a touch of exposure compensation to rectify.
The new 20.1MP sensor is very good, though for best results, we'd recommend using something other than the bundled 18-55mm lens, which doesn't quite do the sensor justice, but will be fine for general shooting.
In our technical testing and using a pin-sharp Sigma 105mm f/2.8 at a sweet sport of f/5.6, the Sony A58 resolves around an excellent 26lpmm (lines per millimetre) at ISO 100, only tailing of to just over 21plmm at its highest ISO of 16,000.
At the Sony A58's base ISO of 100, images appear noise free, though subtle signs begin to appear at ISO 800, with a gritty texture appearing in our Raw files at ISO 1600, with luminance and colour noise increasing in presence as the sensitivity is increased to the point where we'd think twice about shooting above ISO 6400. JPEG files at these higher sensitivities attempt to reduce this effect, but the result is mushy looking files with considerable loss of detail.
Ultimately, the Sony A58 can't quite compete with the competition at higher ISOs, displaying noticeably more image noise than its rivals at identical sensitivities.