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.

FIRST IMPRESSIONS
It’s a scary thing being lent such expensive kit. So I made my first dive with an empty D3 housing and actually shot the D2X for the whole first day to establish some sort of benchmark. But Day 2 was D3 day, as once I tried it, so was every other day of the trip.

My over-riding first impression was how easy this camera was to get used to. For any Subal/Nikon user there is close to zero acclimatisation time to the kit. The Subal ergonomics are superb and consistent with previous housings and every control is exactly where you would expect it to be. It is evolutionary design, rather than revolutionary. The ND3 is a big housing for a Subal, but easy to handle. I should mention that there are many housings by other manufacturers that have been just as big, yet have housed far smaller cameras! The D3 has a 400 page instruction manual, the Subal ND3 has 27 controls yet both are so intuitive that I found no obstacles to just jumping in and taking pictures. I took strong images on my first dive.

The D3 feels just like any other Nikon, albeit with sharper reflexes. Adjusting to FX is not a big deal. Just as the format change from 35mm to DX was something you adapted to immediately you looked through the camera, so the change from DX to FX is a minor issue. Film to digital is a massive adjustment compared with DX to FX. The shallower depth of field of FX means that you have to be a bit more precise with your focus particularly with macro, and given the minor trade offs of bumping the ISO up you have a new creative tool to consider for wide angle. But more about both of those in detail in Parts 2 & 3.

I often feel with housing reviews, the less there is to say the better the housing. A housing is a conduit to the camera and the less obstructive it is the better. I realise that this slogan belongs to another company, but when it comes to a Subal I find “it just works”. And goes on working. I have shot over 100,000 trouble free underwater images with my Subal ND2 housing and the Subal ND3 has identical built quality and I’d expect similar reliability. 

I found all the controls easy to operate with bare hands (Guadalupe), 5mm gloves (San Diego) and 7mm 3-finger mitts (Vancouver Island). Depth rated to 70m (240ft), this system is well suited to just about any diving conditions. On the ND3 the controls have excellent feel - even through 7mm gloves, with numb fingers, it was easy to feel the auto-focus bite point on the shutter. I was also impressed with the gearing of the command dials. You are not accidentally skipping between apertures, nor are you spinning the wheel endlessly just to change shutter speeds a between a balance light and black background. Many housings get this wrong. The push buttons are standard Subal fare, although having tried a few different housings recently I do appreciate how nicely weighted their resistance is. 

My only disappointment with the ND3 was the standard viewfinder. I felt that this gave an inferior view to my ND2 (which also has a standard viewfinder) despite on land the D3 having a noticeably better viewfinder than the D2X. I presume this is a reflection that nearly everyone specifies the GS180 or WS45 these days and Subal put less effort into the standard option. I was not able to get as comfortable a view of all corners of frame through my normal facemask on the ND3 as on the ND2.  If you are considering this system I recommend investing in the excellent GS180 viewfinder.

Continued in Part 2.