Sony Alpha A700 Samples

Below, the Sony Alpha A700 is compared with the Pentax K10D, which uses Sony's previous generation imaging sensor, under a typical night photography setup. Both cameras were mounted on a sturdy carbon-fiber tripod and setup for completely manual operation. At such low-light levels, most camera do not know how to meter, so at least manual metering is required. Focus was manually set to infinity, white-balance was set to tungsten, drive mode was set to use a wireless remote and aperture was set to F8. Speaking of the wireless remote, in North America Sony bundles one with the A700. The Sony 16-105 F3.5-5.6 lens was used at 105mm on the A700 while the Pentax DA 50-200 F4.5-5.6 at 105mm was used on the K10D. Then, three shots were taken at each ISO sensitivity, adjusting the shutter-speed between each shot. The results could not be any more different. The crops below are all unmodified 100% crops from their respective cameras.

At the low ISO settings, the most prominent differences between night shots from the Sony A700 and the Pentax K10D are sharpness and color. Images from the A700 appear significantly softer than those from the K10D. This is due to slow-shutter noise-reduction. This is clearly not due to the lens or JPEG conversion algorithm because our day crops came out quite different. Image softness increases very slowly with both DSLRs as ISO sensitivity is increased. As for colors, it seems both cameras have a very different idea of what tungsten white-balance should be. The Pentax K10D produces much more accurate and neutral colors here. On the other hand, the Sony A700 produces images with colors shifted towards yellow. Strangely, the yellow shift diminishes as ISO increased. By ISO 3200, colors from the A700 are quite neutral. Since the white-balance remains the same, the only possible explanation is that this may be due to chroma-noise reduction performed by the Alpha.

Starting at ISO 400, the Sony A700 begins to show an advantage in terms of image-noise over the K10D. By ISO 1600, images from the A700 are noticeably cleaner. ISO 3200 and 6400, which the K10D cannot even do, are quite noisy under low-light. Under these conditions, ISO 3200 could be used for a small print but ISO 6400 is pretty much useless. Since virtually no other cropped-sensor DSLR currently reaches that sensitivity, it is not really a problem.

Sony Alpha A700	Pentax K10D
ISO 100 15s F8	ISO 100 15s F8
ISO 200 8s F8	ISO 200 8s F8
ISO 400 4s F8	ISO 400 4s F8
ISO 800 2s F8	ISO 800 2s F8
ISO 1600 1s F8	ISO 1600 1s F8
ISO 3200 1/2s F8
ISO 6400 1/4s F8