Nikon threw the photography world for a loop last week by announcing the D600 — a full-frame DSLR that hits a reasonably affordable price point. Apparently, Canon has its sights on the exact same market, as the company has just introduced the EOS 6D: the lightest, smallest, and least expensive full-frame DSLR the company has ever produced. Canon's latest entry not only compares favorably with the D600, it also provides a compelling alternative to photographers who don't have $3,500 to spare — but are nonetheless enamored with the 5D Mark III's stacked spec sheet.