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

WIDE ANGLE
The main reason I planned to snare a D3 for this particular shoot was because I felt that the high ISO capabilities would provide exciting possibilities for wide angle in the dark temperate waters of British Columbia. I also thought that higher ISOs might also be beneficial in Guadalupe, particularly later in the day when the sun typically dips behind the island. Whatever the outcome it would provide diverse challenges for underwater wide-angle photography.

For wide angle I used two lenses, the Sigma 15mm fisheye and the Nikon 17-35mm. I chose the Sigma 15mm fisheye over the Nikon 16mm (of which I own two) because I prefer its closer focus and find it sharper than the aging Nikon. Since I have got used to using the Nikon 10.5mm fisheye, I have been less impressed with the sharpness of the older design 16mm fisheye. The 16mm is not a bad lens, I just prefer the 10.5mm and Sigma 15mm, I don’t recommend everyone rushing out and changing. I selected the 17-35mm over the 14-24mm for two reasons. First, I own one! I was offered a 14-24mm for the trip, but that combined with a D3 is a lot of someone else’s kit to risk below the water. But secondly, I was concerned about the corner sharpness with the 14-24mm particularly because it cannot take a dioptre. So I am afraid there is no test of that lens here.

Ultra-wide angle rectilinear lenses have always been troublesome underwater. Without wishing to run an egg-sucking course for grandmothers, here is an overview of why. Before you skip to the end of this section, understanding the problems of domes and rectilinear lenses is important in understanding why certain solutions work.

Once immersed in water a dome port creates a virtual image that we must focus on, which is both closer to the camera than the true subject and also curved. A dioptre helps the camera focus on this closer virtual image. Land lenses are designed to produce flat images of flat planes of focus. The curved focal plane created by the dome has corners that are closer to the camera than the centre. Typically, we focus on the centre of the image and rely on depth of field to keep the corners as sharp as possible.

Rectilinear lenses are much more sensitive that fisheyes to corner sharpness. One reason is that they have pincushion rather than barrel distortion. This means corner detail is stretched out, rather than squashed in, making flaws more obvious. Furthermore, FX chips are bigger, yet the same distance behind the lens as DX ones, so light rays from the lens are striking the photosites and more acute angles, making light gathering tougher. Perhaps most important, FX cameras have narrowed depth of field at a given focal length and aperture so we struggle more to keep those curvy corners sharp. Theory aside, the proof of these problems is in the photos. Here on Wetpixel there has been no lack of threads with folks struggling to get good corner sharpness with wide rectilinear lenses, both on DX and FX.

Dioptres are useful for two reasons. First, they help the camera focus on the virtual image, which is surprisingly close to the camera (infinity is only three times the dome’s spherical radius). And secondly, and rather fortuitously, single element dioptres actually introduce a bit of field curvature which helps offset some of the curved focal created by the dome. So the big question is would the 17-35mm, with dioptre attached perform behind the dome?

In Guadalupe I was very happy with the performance. I used a +3 dioptre on the lens (I tend to favour the +3 for pelagics and the +4 for reef wide angle with these lenses) a port extension ring and a Subal FE2 port. This review is about shooting real world subjects, and the shark images with the 17-35mm are all very acceptable. I was satisfied that wide rectilinear was working for me on FX and did not even try any other port/dioptre combinations.

Shark photography is not the toughest challenge for corner sharpness. Firstly, most shots do not have any important corner detail. Moreover, corner softness is accentuated by short camera to subject distances, which you would get with reef CFWA, rather than shooting pelagics. So for those who like a bit of measurebating, this thread in the forums has some photos of the cage grid. Normally I would have used the +4 dioptre for such shots, but in any case, these shots are not too bad at all. The corners suffer more with fringing than sharpness and the problems only manifest right in the corners at FX.

There is one important further feature of the D3 that is worth mentioning in respect to dome performance. The D3 has an in-camera AF fine-tune feature, which can remember specific settings for certain lenses. I tried setting a slightly closer focus (than the true distance) for the 17-35mm, to bring the plain of focus forward slightly relative to the curved virtual image to help corner sharpness. I felt this improved matters, but I was not able to achieve any quantifiable results, mainly because the 17-35mm was already working well. When I own a camera with this feature I will experiment further.

Despite getting technically acceptable images with the 17-35mm, I have to admit that I just don’t like the pincushion look of the shots. I am a fisheye guy. Give me cuddly, curvy barrel distortion any day over spikey, pointy pincushion. To me the underwater world looks so much better that way. So most of the time I put the fisheye on.

Optically the Sigma 15mm was superb. There is no doubt that fisheye lenses perform very well on FX, and if like me that is what you like to shoot, then you will be very happy. Up in Port Hardy it was without a doubt the lens to have. The full 180 degree view is definitely what is required for wide angle photography. It allowed me to photograph the colourful walls with a diver or a colourful foreground with the bull kelp towering above as a background.

Well, the Sigma 15mm is the lens to have if you are not lucky enough to be shooting DX and have a Tokina 10-17mm. The 10-17mm fisheye zoom has so many devotees these days, I shan’t waste space singing its praises here. However, since most of my dive buddies had this lens, I noticeably missed it on this shoot, particularly when I saw their pictures after the dive. For some wide angle subjects you just need the full 180 degree coverage, other times, particularly for wildlife you need to zoom in a bit. With the Tokina you can, with FX you cannot. My biggest frustration shooting wide with the D3 was the fact it did not have a Tokina, hardly Nikon’s fault. I was quite surprised by this considering I only started using the lens in the spring of 2007, a few of months before the D3 was announced! To save you thinking it, the 14-24mm, if you could get it working behind a dome, is no substitute as sees only 114 degrees at its widest.

I shot the Sigma 15mm in Guadalupe and was pleased with the spacious images it produced. But such images always look better alongside the high impact face shots, so I needed something longer. With the straight 15mm the white sharks just got too tadpoley – all head and no body at all. With a Tokina 10-17mm you can just zoom in, but on FX I had to find a different solution. I settled on the 15mm with a 1.5x Kenko teleconverter. It does not offer the flexibility of the Tokina, but it did allow me a tighter view.

I have been using the same TC on DX, with the 10.5mm, but I had always used this combination with a tiny 4 inch dome as a wide-angle macro lens. Using the fisheye-TC combo as a straight wide angle lens is not new thinking for FX, Walt Sterns was the first I heard sharing this idea. I mounted it behind the FE2 port and the small port extension ring that, ironically, I have for the Tokina.

The 15mm Sigma and 1.5x TC has a similar angle of coverage as the 17-35mm at 17mm – about 110 degrees. I would say that the 17-35mm is ever-so-slightly sharper in the centre of the frame, but the corners of the fisheye-TC are better and I much prefer the barrel to pincushion distortion. The TC crops out much of the fisheye distortion. On any shoot I’d imagine I’d use both depending on the subject and affect I was after.

For completeness I will quickly mention white balance. The D3 has excellent auto white balance on land. This seemed to work well underwater, when I used it, but I tend to shoot on preset Kelvin white balances underwater. In Port Hardy and San Diego, using my INON Z240 strobes unfiltered I shot at 5400K, which I find reproduces the best green water. In Guadalupe I added Lee 443 gels to the strobes and shot at 4300K. These are the strongest of several gels I use on the strobes, which I chose because I anticipated longer-than-usual camera to subject distances. For more details on strobe filters and white balance see here.

HIGH ISO
Arguably the most exciting photographic capability of the D3 is its noise free performance at high ISO. I was interested in investigating how useful this was beneath the waves. Underwater I found that I could shoot up to ISO 800 without any noticeable degradation in image quality. ISO 1600 could still produce excellent double page spreads and ISO 3200 would be good enough for covers or single page spreads. Incredibly impressive. Nikon users have never known anything like it. The D3 changes how you think about light.

Perhaps my biggest surprise with the D3’s high ISO performance was how I struggled to find subjects that really made use of ISO 1600 and above. On this trip I dived in some pretty dark waters. Below the kelp, in the gloomy waters of British Columbia on a (typically) rainy day is not bright. However, shooting typical wide angle scenes with flash, I found that I never needed an ISO higher than 800. Sure, I could dial in higher ISO settings and they worked, but at ISO 800 I was able to use all the aperture and shutter speed combinations I wished. In other words you have to do some pretty unusual diving to really “need” ISO 1600 to 6400. The obvious examples would be deep or dark available light shots, such as wrecks, particularly with filters.

When you use the ISO settings above 800 you do begin to degrade image quality - not much, but its visible. Therefore it is important to make sure that the ISO setting is getting you something photographically that could not be achieved at a lower ISO. Up to ISO 800 you can increase for free, above this you should not just be using ISO as a crutch for poor technique. I believe that there are many interesting and novel underwater images to come from high ISO shooting. I really felt that I only just started to make use of this potential during my shoot.

In Guadalupe the capabilities of the D3 at ISOs 400-800 were very valuable. Particularly early and late in the day, when the light is often most interesting. My buddy, shooting a D200 definitely found those conditions much tougher. Another advantage of high ISO was being able to use low flash powers, which meant that I could use the camera on continuous low (4-5 frames per second) shooting. Continuous high produces up a ridiculous 11 frames per second. This enabled me to produce a series of shots from a single pass. I also shot some images at ISO 1600 and the noise was much more noticeable in the blues. In the middle of the day I was shooting at ISO 200. In brighter tropical waters I doubt I would find many uses for ISOs above this.

The high ISO capabilities of the D3 are revolutionary for the Nikon shooter and allow you to produce types of underwater images that would be impossible. However, these capabilities only come to the fore the right conditions. If you dive entirely in tropical conditions or shoot macro such abilities will rarely be of any use. 

DYNAMIC RANGE
The D3 can record RAW files at a bit-depth of 14-bit and perhaps equally important is Nikon’s Active D-Lighting, which is a bit like an in camera Shadows and Highlights, and is applied to the RAW file. Both of which promise better dynamic range for digital files. The big question remains is the D3 the camera to finally capture sunbursts just as they look on a tranny on a lightbox? No, is the short answer. I felt it was better than the DX cameras I was shooting alongside, but I would find this impossible to quantify with the real world shooting we did. I certainly do not feel that there is a day and night difference between the D3 and its 12-bit predecessors and I don’t have any shots that can demonstrate it.

At times in Canada the D3 really struggled with the transition from the bright surface to the inky depths. In the blue water of Guadalupe is coped much better and I was much happier with how it recorded afternoon sunrays. These seemed to be a benefit for macro too. I shot several subjects amongst the bright while plumose anemones and I was very impressed with how the D3 coped with these scenes.

But that is all just opinion. Without some controlled conditions testing the different to 12-bit cameras is so small as to be difficult to discern. In conclusion, I have absolutely no complaints with the D3 image quality, which is as good as any underwater camera I have seen. But get feeling I don’t think I could prove to anyone it is any better.

SUMMARY
So will I buy one? I am not sure, I have been hanging on for an FX camera in the 18-22MP range as resolution is more attractive to me than high ISO. I miss it. It is a phenomenal land camera, and a very capable underwater one. For anyone who made the transition of film to DX, DX to FX is much simpler. The Subal ND3 is an excellent housing, but I’d strongly recommend the GS viewfinder. I was much happier than I expected to be with the AF modes, which work really well. Nikon’s biggest job for the upgrade is increasing the AF coverage of the frame, which is currently insufficient (although does exceed many cameras out there).

I think that my shoot definitely played to the strengths of the D3 and particularly with wide angle I felt I was getting images I could not with DX. I might have been less impressed had this been a tropical trip, where the benefits of the D3 over a DX camera would have been more marginal.

The D3 excels at both macro and wide angle and I was satisfied with its performance with the tricky rectilinear wide-angle zoom, with the subjects I was shooting. That said, low ISO image quality (both for wide angle and macro) is very good, but not a step on from current DX cameras and even some that are several years old. If I were planning predominantly coral reef diving (low ISO wide angle and macro), the D3 would be hard to justify over a D300, for example.

In evaluating the D3 I cannot ignore the D700, which makes the same FX arguments at a more compelling price. The only significant feature it does not equal the D3 for underwater photography is the 95% versus 100% viewfinder. Is this worth $2000? Plus it will travel lighter and take a smaller housing.

So should you get a D3? As I have said above, a lot depends on the type of diving you do. If you frequently shoot wide angle in dark conditions then the D3 will open up new images to you. If you dive mainly in brighter conditions or if you are a macro fanatic then the D3 will offer you little to justify the cost of FX over DX.

There is much passion invested in the D3: the handling of Giugiaro designed body, the feel of the controls beneath your fingers, its bristling reflexes and instant readiness. And as a result, investing in a camera such as this should not just be about dry facts and figures. It is an emotional decision too. For most people underwater photography is not a profession and I could completely understand anyone wanting to use the D3 just for the quality of its ergonomics and capabilities. You experience these with every frame you shoot, particularly in the Subal ND3. If you decide that this camera is for you, then you will not regret your purchase for a second.

To conclude. The D3 takes excellent macro and wide angle underwater photos. I love the D3’s screen (also on the D700, D300 and D90).  I miss the Tokina! I miss the D3, now it is returned. FX is great and easy to adapt to. However, the advantages of FX really depend on what you photograph. If you shoot mainly in the tropics or shoot mainly macro then FX offers little over DX. However, if you shoot plenty of wide angle in low light, then the D3 won’t just allow you to take types of images you never could before, it will change your approach to photography in these conditions. This makes it a very exciting underwater camera.

ACKNOWLEDGEMENTS
Sincere thanks, once again to Ryan Canon at Reef Photo Video and Craig Jones for trusting me with the Subal ND3 and Nikon D3, respectively. I am incredibly grateful to fellow photographers Rand McMeins, Todd Mintz, Jeff Hartog and Allison Vitsky for helping me through the complex itinerary of this trip (UK-USA-Canada-USA-Mexico-USA-UK). I’m lucky to have friends like you and look forward to diving together again soon! Thanks Todd for lending me your buoyant StiX arms, John Davies for giving me that tub of o-ring grease that kept the expensive camera dry and also Carol Grant (who I didn’t get to dive with this time) for lending me your official Subal 105 VR port. I would also like to thank the dive ops, Mamro Adventures in Port Hardy, Marissa Dive Charters in San Diego and the guys from Shark Diving International and the fabulous crew on the Solmar V for our adventure in Guadalupe. Finally, I’d like to thank my photo-buddies on this trip for their excellent company, sense of humour and advice through the trip: Todd Mintz, Rand McMeins, John Davies, Allison Vitsky, Mike Bartick, Brett and Stephanie Tischler, Calvin Penfound, Marianne Lawrence and Jeff Hartog as well as everyone on the Solmar V.

- Alex -

FURTHER READING
Having suggested at the top of this piece that others using the D3 have been a little secretive of their opinions, I thought I should add some links to those who have shared their thoughts!
Jason Heller on the D3 in Sea & Sea housing – DPG - www.divephotoguide.com (coming soon)
Charles Hood on the D3 in Aquatica housing – UWP Mag Issue 44. www.uwpmag.com

Finally, there is a small gallery of some of the D3 images I took during this trip here.