Sony launches full-frame Alpha DSLR

Sony today at last branched into full-frame digital SLRs with the Alpha A900. The camera aims to outsize both Canon and Nikon with a 24.6-megapixel full-frame sensor, the company's first, that Sony claims is also extra-flat and has on-chip DACs that minimize noise as early as possible in the shot. The electronics maker also outfits the A900 with a 100 percent optical viewfinder and dual BIONZ imaging processors that keep the frame rate up during shooting: it can manage up to five frames per second at full resolution. A new mirror box design for the SLR mechanism makes sure these features don't swell the camera's size.

The camera doesn't support live previews but finds a unique method of previewing shots before committing to the final photo: the camera can sample the scene in RAW and lets users choose the depth of field, dynamic range, white balance and other settings based on the reference image on the three-inch LCD.

Sony promises image stabilization built into the camera body, nine focusing sensors with 11 assist points and +/- 2EV bracketing to get proper exposure even in dark scenes. HDMI provides previews of images and lets users adjust the image output independently for the TV itself.

Sony starts taking preorders for the A900 on Wednesday and ships it in November at the same $3,000 price as the Nikon D700 and similar-class cameras. It will be followed in January by a Vario Sonnar 16-35mm, f/2.8 lens at $1,800 whose focus and fixed aperture suit it to wide angle and low-light shots; a second, 70-400mm f/4-5.6 lens at $1,500 is suited more to telephoto-style shooting for nature and sports.