Sigma has rolled out an upgrade to its SD14 digital SLR camera. The SD15 has been announced at the Photo Marketing Association tradeshow in Las Vegas, and adds SD card compatibility, as well as promising a particularly durable shutter mechanism.

Inside, there's a Foveon X3 image sensor, Sigma's TRUEII image processing engine, RAW recording of up to 21 frames in continuous shooting, a 77-segment AE sensor, and on the back there's a 3-inch TFT colour LCD display with 460,000 pixel resolution. The UI has been upgraded too, and Sigma reckons the shutter can handle more than 100,000 exposures before dust begins to become a problem.

ISO runs from 100 to 1600 in normal mode, and in extended mode it'll go as low as 50 and as high as 3200. There's a 5-point cross-type autofocus sensor, and four metering modes with auto bracketing for three or five exposure levels. The built-in flash offers a 17mm coverage angle, and the Sigma promises 500 images on a full charge of the battery, which then takes about 2 hours to fully recharge.

We don't yet have any pricing or availability details for the SD15, but as soon as we hear anything, we'll tell you.