Here is a short chronology of events:

1957: the Belgian inventor Jean de Wouters makes the CalypsoPhot for the dive equipment manufacturer SOS. It becomes the first waterproof 35mm amphibic camera with 35mm lens that can be used both above and under water. It came on the market in 1961 with a 35mm and a 28mm lens, 1/20 to 1/1000s

1984-??: the Nikonos V with electronic TTL through the lens light metering and a wide range of shutter speeds, receives an enthusiastic welcome. It also controls and mixes the strobe light of the new strobe models SB102, 103 and 105 at all shutter speeds to 1/90. The Nikonos now has watertight exchangeable lenses of 80, 50, 35, 28 and the famous15mm and is still today a good expedition backup camera in case all else fails due to dust, dew, moisture or ice. It can be fitted out with several Nikonos underwater strobes and strobes made by other manufacturers. A large variety of accessories is available from brackets and macro tubes to flash synchro cables.

1992-96: the Nikonos RS 35mm SLR autofocus autoexposure camera for depths to 100m, with an extensive set of very high quality underwater lenses, sets the standard. Although it was the camera everyone had been waiting for, it was taken off the market in 1996 due to poor demand and internal restructuring at Nikon Japan. In slow succession its lenses became available: 28mm, 50mm macro, 13mm fisheye and 20-35mm zoom. Specialty lenses became available from other manufacturers, notably from Germany. The SB104 strobe is the most powerful on the market, designed for fisheye lenses.

Today in the age of computers and digital cameras, it is hard to imagine that underwater cameras took such a long time to evolve from their basic models. Even so, they do not match what the digital camera of the future may offer. In today's digital cameras we already encounter an adequate resolution and colour sensitivity, the ability to balance and filter colours, and a seemingly inexhaustible storage cartridge for far more than 36 exposures. And they have a long list of additional features. But most of these features do not count underwater, where a basic camera is all one needs. Indeed many digital cameras in their small housings fail the basic requirements for underwater use, the subject of this chapter.

• non SLR: one views the subject through a viewfinder placed above the camera but the lens is not in any way coupled to this viewer in order to judge the point of focus. But it is a wide viewfinder suitable for the 80mm, 35mm and 28mm lenses. For wider lenses an additional viewer must be mounted on the strobe type shoe on top of the viewfinder. No special adaptations are needed to view with a dive mask on.
• limited focal distance: the 35mm lens focuses down to 80cm above water, which is 106cm under water (a range of 1-1.25 diopter). External closeup lenses are needed to focus nearby.
• magical 15mm lens: the UWNikor 15mm lens is a very sharp wide angle lens, corrected for the air-water interface and able to focus closeup to ??mm.
• sharp macro: closeup photography with the 28mm and 35mm lenses using distance rings, gives sharp results with good depth of field, better than a 100mm macro lens could.

• general photography: it is a robust camera with dependable light metering and strobe control and a good tool where environmental conditions are harsh, such as moisture and dust. It has always produced good action shots of surfers. Note that the 35mm lens can produce a blue spot in the photo, caused by sunlight reflecting on an internal lens. Keep direct sunlight out of the lens.
• macro camera: the 35mm and 28mm lenses used with fixed distance rings and framers, still give the sharpest images with the most depth of field.
• backup UW camera: we all hope that our main camera and strobe will work flawlessly during our expensive holiday or even more expensive contractual shoot. But what if it fails? Are you coming home with no shots at all? As a backup camera the NikonosV can still take good photos and it is such a small package (body + 35mm lens + Sea&Sea 16mm lens + distance rings) as it uses the same strobes and brackets from your main camera. Make sure how to work it and keep spare batteries handy.

• expectation: underwater photographers knew it was coming and had high expectations. They expected a camera like the NikonosV but with a mirror-reflex system, while perhaps even using the available Nikonos lenses. Because of this high expectation, disappointment had to be deep.
• quality: Nikon's expectation was different as it was ready to make the best underwater camera ever. The US Navy placed a large order, and they required a camera that would work to 100m depth. So it became bulkier and heavier. With hindsight, one can see that Nikon has indeed made no compromises. They even developed new technology that would later be incorporated in all their topside lenses.
• price: the high price of this camera was its main disappointment. Little did people realise that what they paid for is what they got. It is caused by the gulf of difference between the professional who knows that quality is what you pay for, and the amateur who thinks he would not need such quality.
• marketing: it could be argued that the people knowing least of the potential of this camera, were found within Nikon Headquarters. Marketing was weak, and never were the camera's qualities that really mattered, mentioned. Salesmen didn't know and potential buyers did not get informed.
• wrong sales network: here was a product for a very small niche market, but Headquarters chose to market it through their normal worldwide distributors and retailers of snappy cameras. It meant that really nobody knew how good this camera was and how to sell it. It also meant a large markup to retail price. This happened at the same time the Internet grew useful. This camera should have been marketed over Internet and this would still be viable today, witness sales from E-Bay (www.ebay.com).
• slow release: a definite mistake was the slow release of essential lenses. It took a long time before other lenses than the 28mm standard lens became available, and all that time the camera was essentially unusable.
• hysteria: a world-wide hysteria of disappointment spread like wildfire, not helped by very little experience (and thus photos taken with it).
• internal reorganisation: what few people remember was a major shake-out happening between camera manufacturers in Japan. It all began with infringement of US autofocus patents, and it ended with major internal reorganisations within those companies. One of the decisions of the bright boys from Headquarters was to axe the Nikonos RS, a decision that may be regretted in the long term. Here was this vast investment in research and development, thrown to waste. But who knows, one day a digital camera insert may be slipped into an RS body, and make this R&D come to fruition again. (but digital cameras use a CCD which is smaller than 24 x 36mm)
• flooding: there were reports from flooded cameras, and these stood out not because of it happening but of the capital involved and the perceived risk. More about that in the tips and tricks chapter.
• maintenance: this was a camera that could not be serviced by all and sundry, mainly because it was almost impossible to guarantee to a depth of 100m, which required test capabilities to 200m! So, sending it back to a very few service centres was necessary. Nikon stipulated further that the warranty would expire if not serviced preventatively every year at a substantial cost, exacerbated by high freight costs (and agent's markups). It never explained why, and with hindsight, this requirement could have been relaxed. What people don't realise is that salt water sneakily corrodes the bits that seem unessential, like the screws in the body that cannot be rinsed. So periodic removal and replacement of such unimportant bits, is actually very important. For myself, having Nikon's service department behind me, gives me confidence in my equipment, knowing that whatever happens, it can be fixed, and that my investment is protected. In the past three years their service department in Japan has provided me with exceptional service, professional skill and prompt delivery. How much is that worth to you? A lot to me.

Let's now review the camera's features and what these mean to the underwater photographer. The camera was conceived at the time of the f801 and its insert indeed resembles an F801 camera body, as does its bayonet lens connection. But major modifications have been applied.

• autofocus: having an autofocus camera rates as the most essential feature to me. There is just no time to judge focus through a viewfinder and turning knobs. Most opportunities last only for a fleeting fraction of a second, but enough for the autofocus mechanism. For people with limited eyesight, it is simply indispensable. Compared to a camera with manual focus, it enhances your chances at least tenfold. But autofocus is a nuisance on unmarked grey objects like dolphins, and in those cases a preset focal distance works best. Autofocus can also be a nuisance in very tight macros. The RS has extended this idea fourfold:
• single shot: the camera fires one shot only when in focus and not otherwise (focus priority). Important for most situations. When in focus there is no delay.
• continuous: the camera focus follows the subject as long as the shutter button is half depressed, but will fire immediately as many shots as long as the button is pressed down (shutter priority). Ideal for nervous subjects moving within the depth of field range given by aperture settings. Use this focus mode where the right moment is more important than precise focus.
• power (manual): The RS has a special rocker button to focus manually. It also has two depressions: slow and fast. Manual focusing is important for shooting dolphins and whales, inside caves and more. When autofocus won't work due to light conditions or faint subjects.
• freeze (preset): a very useful feature not normally found elsewhere. The focus is preset and when a subject presents itself in focus, the shutter releases. Ideal for supermacro photography where autofocusing is a nuisance. It combines the benefits of auto and manual focus. Prepare the focal distance by aiming at a rock, doing it manually or so, then turn the focusing system to Freeze. Now focus by moving the camera forward while retaining composition. Ideal for macro photography when everything moves through wave action.
• autofocus lock: focus and keep the shutter release button half depressed. Then compose and shoot. Most cameras have this feature but it is very important to have.
• fast shutter: the RS synchronises with a strobe at up to 1/125s. This enhances opportunity significantly over a 1/60s speed.
• aperture: the RS (I think) is the first camera that controls aperture by an electric signal rather than by turning a ring on the lens. In underwater cameras this normally requires a clumsy mechanism and a dial hidden somewhere on the front of the housing or side of the lens. But on the RS it sits as a large dial on top where it adds to simplicity of operation.
• simple operation: the RS is the ultimate in simplicity with aperture autoexposure only, precisely the most successful method under water. It has large buttons which are easy to operate even with 5mm gloves on. In the dark one blindly finds the right buttons and their settings show in the lit status bar. All important settings are done by the right hand. With the left hand over/under exposure is set.
• large reflex viewer: the viewer is exceptionally large, extending high above the housing, giving full view of the entire image and the status bar underneath. Until you've had one of these viewers, you simply don't know how important it is for success. Internally Nikon placed a large and complicated prism with sharp optics. The viewfinder screen is also exceptionally bright. But there is no ocular adjustment for near- or far-sightedness. It is assumed that your dive mask does this.
• status bar: the status bar or LCD readout under the viewfinder screen shows autofocus status, auto exposure status, shutter time, aperture and over/under exposure for manual control. The LCD is bright and easy to read, allowing you to change settings while peering through the viewfinder. This is particularly handy with wary objects where every movement invokes suspicion. Note that when peering at dials, one needs to turn the camera and with it the strobe, which altogether is a major movement.
• matrix metering: matrix metering was already part of the F801 generation of cameras, and this has been sold as an advantage. The camera indeed produces quite good exposure metering but can be confused in unusual situations. In manual mode when shutterspeed is selected manually, the exposure metering reverts to spot metering.
• exposure compensation: the RS has a separate dial for exposure compensation to enable bracketing. But this alters both strobe and ambient light intensity. To control each separately, one must revert to manual mode, reading over/under exposure of ambient light from the status bar and using the exposure compensation dial to control the strobe. It works indeed very well with the use of filters. One can then apply colour without shadows, creating a very natural look in mixed-light photography. The exposure compensation dial is not strictly necessary if it can be done by changing the ISO setting but when using a wide angle lens, is changed often.
• rear-curtain flash: a slide switch sits as an afterthought inside the back cover and cannot be operated from the outside. Rear-curtain flash fires the strobe at the end of the exposure, which places the silhouette of a moving fish behind its tail rather than in front of its nose. This setting also allows aperture priority autoexposure to extend shutter time beyond 1/30s. It is a refinement typically for underwater photographers and it does not hurt to take this as the preferred mode as long as a tripod is available. For macro photography the shutter speed is set manually to 1/125s.
• manual or automatic ISO setting: so often the automatic DX sensor fails (also on other cameras) and I prefer now to do this manually. It is indispensable when pushing a film to a higher ASA rating or when preferring slight over (negatives) or under  exposure (slide)
• remote shutter release: an additional 4-pin waterproof plug allows one to connect a remote control through a 3m cable. It enables one to place the camera on a (heavy) tripod for taking photos of shy creatures. The remote control push button works like the one on the camera, focusing when pressed halfway down and clicking the shutter when pressed fully. An LED light provides feedback of the strobe's readiness. This is perhaps the only camera in the world with such an option.
• invisible features: this camera has a number of important features that are not immediately evident.
• strength: the camera is extremely strong and rugged, except for the lens housing bayonet which from necessity had to remain relatively thin. An exchangeable lens has two bayonets: one ties the housings together, the other the lens to the internal camera body.
• coating: the colour of this camera is grey not because the arts department said so but because this is the hardest anodised coating one can give aluminium. Aluminium does not rust because of a thin oxide skin. Anodising can thicken this skin, also making it very hard.
• lens coating: the lenses also have the hardest and most salt-resistant coating ever made. So they should be long-lived. Nonetheless, after a dive, rinse the camera and lens and then gently wipe the lens dry to prevent spotting.
• materials choice: only the highest quality materials have been used in making the underwater housings of camera and lenses.
• sharpness: the UW Nikkor lenses are all sharp at their widest aperture, thereby extending your opportunities in low light conditions.
• round aperture: the aperture inside the UW Nikkor lenses have so many lamella that they are effectively round, not triangular as in some cheap cameras or hexagonal in more expensive cameras. This makes scatter less recognisable.

• R-UW AF Nikkor 28mm f/2.8: the 28mm lens is the cheap option to begin owning an RS. But it is a sharp lens. A true 28mm lens without distortion or blue edges is a gem to possess even though this lens focuses down to only 26cm (4 diopter). It has an 88mm screw thread for its lens cap and any accessories. Note however that an 88mm filter must be mounted under water or would otherwise be crushed while going down.
• R-UW AF Zoom-Nikkor 20-35mm f/2.8: for many the work horse for its zoom capability, even though it won't focus closer than 38cm (3 diopter) but the 35mm gives very nice closeups at this distance. It has a large dome port.
• R-UW AF Micro-Nikkor 50mm f/2.8: an awesome macro lens that focuses down to 16cm (6 diopter) producing 1:1 enlargement. It can be used above water because of its flat port, which is sometimes handy when taking photos in and above rock pools. This lens is also excellent (the best) for aquarium photography. It also has an 88mm screw thread for its lens cap or accessories. An excellent lens for modelling.
• R-UW AF Fisheye-Nikkor 13mm f/2.8: the super-wide angle lens is also a 'macro' lens as it focuses down to 14cm (7 diopter). This allows you to bring in a single image that which is very nearby and objects far away. It is a very creative lens but also difficult to master. This lens brings the ability to take reasonable photos in very dirty water of less than 1m visibility but it has been designed with barrel distortion, which can be eithervery creative or annoting.
• Lenses supplied by other manufacturers: the Nikonos RS has inspired others to make the best but all these efforts have been undone by Nikon's fateful decision to discontinue the RS.
• 2x teleconverter: made by René Aumann (Germany), changes the 50mm macro lens into a 100mm macro lens with magnification of 2:1. An awesome tool to keep some distance between you and your subject and to let strobe light in. Sharp but camera movement during the short period of strobe light, becomes noticeable.Also takes a long time for auto-focusing
• 18mm rectilinear wide angle: made by René Aumann (Germany), is a very sharp wide angle lens without barrel distortion. It has a large port. A very beautiful addition to the RS range of lenses but also very expensive. Perhaps your best choice for modelling and fashion under water.

f037625: with a correction lens behind, the Nikon Fisheye 13mm can be used above water. Edge to edge sharpness from foreground to background, but on closer inspection, slight red edged, as can be expected from a corrected underwater lens. Even lighting by SB104 strobe.

f040931: this 12mm aeolid nudibranch was photographed with a 50mm macro lens and 2x teleconverter in wavy conditions using the Nikonos RS Freeze focus ability.

For the more advanced user there are a number of gripes about the Nikonos RS:

• tray and brackets: the camera tray (on which the camera is mounted) and its strobe brackets are not flexible and do not meet the demands of the advanced underwater photographer.
• knobs turning the wrong way: when you are placed blindfolded with the RS in your hand and asked to increase the aperture number, which way would you turn the knob? Which way for over and under exposure? And which way for the shutter speed? Which way to move the rocker switch for focusing? Well, they all seem to operate the wrong way. At least the camera is right-handed with most important dials and the shutter release button where you expect it.

The Nikonos RS comes with a single-sided or a double sided tray with a single or double part arm joined to the tray by a quick-release mechanism. The arm is jointed by a double ball-joint which allows much freedom. The whole setup is rather heavy and large.

The large and intuitive controls on the Nikonos RS makes this camera 'love at first sight' for the advanced photographer. All important controls on the right include the focus priority which is a new feature. All lenses have a wide viewing window to read their distance settings, which is also lit at night. Only the film counter, hardly seen here left of the aperture dial, is hard to read even though it is lit at night and has a magnifying window.

See also the tips and tricks chapter for alternative brackets, fast lens caps and filter change, replacing sub-C cell nicads in the battery pack, and more.

Let's first consider their advantages:

• autofocus: the more expensive digital cameras can focus continuously into macro range, solving one problem of macrophotography.
• autoexposure: the quality of autoexposure depends on price and make of camera but most now have exposure programmes for different situations like landscape (average), sport (fast shutter), portrait (large aperture), night (over expose), macro (small aperture), and so on. But for the professional photographer who likes to makes his own (and better) settings, these programmes are of little use. For instance, the camera cannot sense that a tripod is used.
• mixed flash fill: the camera controls flash light intensity very well, able to produce perfect mixed light photos.
• high depth of field: because the CCDs are usually small (6-24mm), the focal distances of the lenses used are also small, which improves depth of field considerably.
• soft tone: digital images are usual poor in contrast which enables them to store more f-stops in the limited signal space of 3-byte JPEG.
• variable sensitivity: in order to match the analog camera's choice of film speed, digital cameras either adjust sensitivity automatically or allow the photographer to control simulated ASA film sensitivity settings. In this manner the one camera has a range of virtual film types.
• large zoom range: often because image resolution is less, digital cameras come with an astonishing zoom range, but with poor wide angle capability.
• large storage: digital cameras are usually able to store more than 36 exposures, depending on resolution and the size of its memory card.
• display image: to be able to see the result immediately, is of considerable advantage as it allows one to take immediate remedial action, which includes reframing, zooming, different angle and of course improved lighting.
• delete image: very important to save storage space and to allow for a more exploratory way of taking photos.
• immediate use: the camera can be connected to a computer or printer and results used very shortly after taking the photo.
• many options: cameras offer many other options such as sound recording, movie clips, in-camera editing and so on.

• shutter delay: the most annoying thing about many digital cameras that there is a forced delay between pressing the button and the moment the photo is taken, often taking 0.5-1.5 seconds! This makes them unsuitable for situations where the moment is critical such as sport photography, and even baby photography. Most underwater photos are critical in this respect.
• slow reset: whereas a classical camera only needs to transport the film, a digital camera needs to write the image to (slow) memory, which can take several seconds, depending on image size. Thus a repetitive shot cannot be taken quickly.
• red-eye pre-flash: red-eye pre-flash further delays the moment, and on many cameras this cannot be disabled. Underwater it scares fish. Turn it off for underwater photos.
• display-based: the mode of taking photos is to hold the camera at some distance and judge composition by the image on the display, which has several disadvantages:
• slow action: aiming the camera correctly, is much slower than when viewing through the viewfinder.
• missing detail: the small display cannot show as much detail as a good viewfinder. One needs to have good eyesight to be able to view a display close up as well as the subject further away. In a good viewfinder both the image and the camera settings are seen at a similar distance, requiring the eye to accommodate less. It is for instance difficult to judge whether a subject is smiling or has its eyes closed.
• movement: holding a camera at distance does not benefit from the stability offered by one's head, resulting in much more movement unsharpness.
• small image: even though the result is immediately viewable, the display is so poor that one cannot fully judge either colour, contrast, brightness or sharpness.
• ambient light: the LCD screen is usually not bright enough in ambient daylight, like not having a viewfinder at all.
• complicated operation: changing the settings on most digital cameras is very geeky (computer like) with dialog windows, cursors and action buttons. It is not possible to do this blind-folded or in darkess. People with poor eyesight need closeup lenses. By contrast, the traditional camera has large dials and these can be set in complete darkness (f-11 = 4 clicks away from fully clockwise, e.g.)
• low power flash: small cameras cannot have big strobe capacitors and their strobe light is therefore much less powerful than that from traditional cameras.
• flash too close: the small strobe light is placed close to the lens, which causes red-eye and underwater the worst of scatter. Only in very tight macro photography can the internal strobe be used under water. In all other circumstances it contributes to disappointing results.
• no remote flash connector: most digital cameras are so self-contained that they do not provide a connector for a remote flash. Many do not even have a tripod screwhole. For underwater use, this is unacceptable.
• poor remote strobe control: some digital cameras can control an external strobe by sending pre-flashes containing strobe setting information. But these are not always received, which introduces a high degree of uncertainty in underwater mixed-light photography.
• needs off-line storage: whereas the classical photographer works with film cartridges stored in waterproof film cans, the digital photographer needs to have enough flash cards or a laptop computer for offloading them.
• lacking colour detail: digital still cameras have only one CCD with which three coulours (RGB) are 'guessed' by alternating pixels, sensitive in either R G or B. In smoothly changing grades of colour, this can be seen as a smoothed-over effect or as bands. In dark areas it causes high colour noise.
• lacking detail: with 6 megapixels the digital camera comes close to the classical 35mm camera (3000x2000) but modern films with modern lenses do a little better (4500x3000 = 13.5 megapixels). One must be alert to false claims and that the claimed number of pixels is not generated by interpolation. Also the lens system must be sharp enough to justify it.
• lenses not water-corrected: the digital camera is often housed in a small underwater housing with a flat port, which limits the use of the wide-angle part of the zoom lens. The lens is also not corrected for the air-water interface, causing blue edges.
• poor wide-angle performance: The wide angle lens is very important underwater and underwater wet-mate lens attachments (for wide angle use) are usually of poor quality.