Just below, the Sony Alpha A200 is compared to the more expensive 14.6 megapixels Pentax K20D. Below are 100% crops taken from full-resolution images at each ISO setting from its respective camera. These shots were taken at night using aperture priority, automatic white-balance and set ISO sensitivity.

Although the images were taken within a ten minute period, light levels were dropping fast enough that exposure parameters chosen by the respective cameras changed during the shoot. Both cameras however kept a consistent image brightness. The resulting images are quite different, showing that the Sony Alpha A200 and the Pentax K20D take different approaches with respect to exposure, color and noise-reduction.

The Sony Alpha A200 takes an aggressive approach to noise-reduction during long exposure, something that we have seen the Alpha A700 do too. Compared to daytime shots, even ISO 100 is softer. As ISO increases, image softness for the A200 increases too. While softness increases slowly until ISO 800, noise becomes destructive from ISO 800. Still, even ISO 1600 is useable for relatively small prints. The Pen tax K20D, contrarily to the Sony A200, keeps much more details at all ISO levels but also shows more pronounced noise starting at ISO 200. That being said, noise on the K20D becomes truly disturbing only at ISO 800 and up. It is not clear if anything can be done with the ISO 3200 shot, but the ISO 6400 shot is useless.

Metering on both camera is different too. The Sony always produces brighter images than the Pentax. Generally, this is better for direct image printing. Also, the chosen white-balance in this case is more yellow on the A200. This was one of the rare cases where the K20D chose a more accurate white-balance than the A200. To be fair, this is not an ideal comparison since falling light levels caused the mix between natural and artificial light to change.