This field-review is long, so I have divided it into three parts:
Part 1: Introduction and first impressions and handling. Below.
Part 2: Shooting macro, lens selection, diffraction, autofocus performance and modes.
Part 3: Shooting wide angle, lens selection, high ISO, dynamic range and conclusions.

INTRODUCTION
Ever since the first “full frame” digital SLR appeared we’ve debated their pros and cons versus the smaller APS-C or DX sensor cameras. Many of the arguments focus on dry statistics, theorizing or pool tests with smudgy corners. I find these discussions interesting and useful, but as an underwater photographer what I really want to know is how a camera performs with the subjects I want to shoot – rather than swimming pool tiles. As we said at school, too much measurebating can make you blind. To photography. Or something like that.

So for this review my intention was take a full frame camera underwater, under a range of normal diving conditions and take photographs of real subjects. It’s a less objective approach that a strict A versus B in the pool review, but I hope more relevant. I took my D2X along for a DX comparison. For obvious reasons, this review is aimed mainly at Nikon shooters who are considering FX. I did not shoot any side by side DX vs FX images, but, throughout the trip I was shooting alongside talented snappers (and well-known Wetpixel folks), all of whom were shooting APS-C cameras, which provided an excellent point of reference.

One area I do score with objectivity is that I do not own or sell any of this kit! The majority of reviews of underwater photography equipment tend to be written by people either who sell it or have just invested in it. Despite this, most reviews I see remain fair, but in this case I can assure you I have no FX Nikons (yet) to justify or sell. I am extremely grateful to Ryan Canon of Reef Photo Video for lending me the Subal ND3 housing and to Craig Jones, fellow moderator here at Wetpixel for trusting me with his D3.

These fieldnotes come from my experiences during a two-week shoot in the East Pacific, where I was able to use the D3 underwater in Canada (Port Hardy), California, USA (San Diego) and Mexico (Guadalupe Island). I spent more than 35 hours underwater with the camera in everything from clear blue water to murky pea-soup and from beautiful walls to kelp forests and in shark cages. So feel I have given it a decent work out in a variety of conditions.

Nikon announced the D3 over a year ago and topside reviews have been everywhere. So I am not going to spend long on the dry tech. If you are interested enough to read this, you will certainly know all about the D3 by now. Underwater opinions have been scarcer. Since the beginning of this year many folks have been shooting with it underwater. I have been on several trips with people with D3s, but I have been a bit disappointed that so few of these photographers have been prepared to share their images and thoughts. Maybe the camera is not producing the goods, or perhaps it is so great that these folks don’t want to encourage others to use it!! I decided it was time I found out, especially as the Nikon D700 has hit the market with housings certain to be everywhere at DEMA and Antibes.