Nikon’s new D850 full-frame camera is proving to be one of their most popular cameras ever, and what’s not to like? A massive 46MP sensor with resolution that matches or exceeds film, fast autofocus (AF) borrowed from the pro-level D5, low base 64 ISO to better capture bright scenes and a fast 7 fps frame rate with an electronic front curtain shutter, for just a start. Matching that are improved flash electronics, TTL protocols and 4K video. For those D800 and D810 underwater photographers who fell in love with shooting full-frame images, the upgrade is intriguing. As I now have around 60 dives on this new Nikon rig, I can offer a comprehensive review.