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 im
