Sigma anounces SD10 DSLR in Japan, plus a pair of new zooms aimed directly at DSLR users.

Official press releases and detailed specifications, click here

Sigma Corporation in Japan has announced a second-generation Foveon X3-based digital SLR, the SD10, which succeeds the original SD9 introduced just over a year ago. A new version of the Foveon X3 sensor chip used remains the same physical size and resolution (2268x1512x3), though some developmental improvements have been made, including the addition of microlenses. Sigma says that the new chip offers improved dynamic range.

A pair of new 'digital' zoom lenses has also been announced by Sigma, these have reduced image circle sizes for specific use with small format or so-called APS-sized sensor DSLRs, including the Sigma SD9 and SD10. When used on Sigma's own SD-series cameras the new 'DC' lenses have equivalent zooming ranges of 30-85mm at f/3.5-5.6 and 85-340mm at f/4-5.6 and are notably smaller and lighter than comparable Sigma zooms designed for full-frame use. With Canon and Nikon APS DSLRs the zooming range will be slightly lower down the equivalent focal length scale as the Sigma sensor is slightly smaller.

Sigma's SD digital SLR series is fascinating because it is currently unique in using Foveon X3 sensor chip technology. X3 differs from conventional CCD and CMOS sensors because a bayer filter, which records the intensity of a single primary colour at each pixel site, is not used. Instead, each X3 pixel site has three photodiodes collecting light from three primary colour filters sandwiched on top of each other.

As there is no need to interpolate the colour information, colour sharpness is much higher. However, fine-tuning the design of the X3 chip has been a challenge for Sigma and while the first-generation SD9 camera showed a lot of promise, there was some evidence that colour information that ought only apply to one photodiode, was evident in other photodiodes collecting light of the two other different primary colours.

Like the SD9, the new SD10 is a proprietary Sigma platform camera, using Sigma's own lens mount system. Improvements in the SD10 include the uprated Foveon X3 sensor, a wider ISO range, faster in-camera image processing with continuous shooting of up to 30 frames being possible. You also get a wider shutter speed range. There is also an improved version of Sigma's PhotoPro image processing software that the camera depends on heavily.

The SD9 and SD10 both record 3.4 megapixel images, but the chips used each have 10.3 million photodiodes. Sigma argues that there is even more image data recorded than a conventional 10.3 megapixel sensor because there is no colour interpolation. Sigma's specification sheet for the SD10 refers, rather confusingly, to a pixel resolution of 10.29 megapixels.

Opinion has been very split over the quality of images produced by the SD9, with some falling in love with its colour vibrancy and clarity, while others complaining of false detail and doubts about the true resolution of the X3 sensor. The SD9 camera body, based on the SA9 film camera was not enthusiastically received either, especially as it was necessary to use post-processing of RAW format image information, using Sigma's PhotoPro software to get even a basic JPEG file. This remains the case with the SD10.

More information is likely to emerge over time about the new cameras, lenses and accessories from Sigma. There is no information yet about UK availability or pricing.

Official press releases and detailed specifications, click here

LetsGoDigital SD10 news coverage

Digit.no coverage (English and Norwegian)