We just added studio test scene images to our First Impressions Review of the Nikon D4s. The D4s is a refined version of Nikon's flagship DSLR, incorporating several changes - large and small - resulting from feedback from professional users. As well as minor ergonomic refinements and a slightly improved video mode the D4s also offers a highest ISO sensitivity of 409,600 (equivalent) - the highest we've ever seen. Click the links below to see for yourself what that looks like.