Page 241 - Green - Maritime Archaeology: A Technical Handbook. 2nd ed

220 Maritime Archaeology: A Technical Handbook, Second Edition
These problems are all resolved with the Nikonos system, but unfortu- nately the system is expensive, especially if the 15-mm water-corrected lens is used. Nevertheless, the benefits of the system, in my opinion, far outweigh the cost.
The Nikonos system has undergone a number of changes over the years, starting out as the Calypso, then followed by the Nikonos I (Calypso- Nikkor), Nikonos II, Nikonos III, Nikonos IVA, and finally, the latest Nikonos V. Apart from the Nikonos IVA and V, which are battery depen- dent with automatic exposure, all the cameras are essentially the same with minor improvements and modifications and can still be obtained second- hand. The instrument is basically a nonreflex, watertight camera, with all controls and openings having very effective watertight seals. The lens system is bayonet-mounted, enabling a number of different lenses to be fitted. The camera body has a focal plane shutter and a small, nonreflex viewfinder. The shutter speed control ranges from a 500th to a 30th of a second and time delay.
It is generally considered that the Nikonos II is a more robust camera than the Nikonos III. The Nikonos IVA incorporated major changes in the design. There were a number of improved features including an automatic shutter control system. All the original lenses could still be used, except for the 15-mm water-corrected lens. It seems that the Nikonos IVA exhibited a number of problems and, as a result, Nikon released the Nikonos V. This included further improvements like a redesigned rear door and a different meter readout with LEDs giving the shutter speed, and comprehensive exposure control system including manual and automatic control of shutter and flash. The present indications are that, although technically superior to the III, the later Nikonoses are prone to flooding and when this happens it requires expert attention. On the other hand, if the Nikonos II or III flood, they can be washed in fresh water, carefully dried out, and reused. In my opinion, although the automatic exposure system of the Nikonos V has great advantages, the possibility, in field conditions, of flooding with permanent catastrophic results is a major shortcoming. If the Nikonos II or III flood, with a simple treatment the camera can be back in operation within 24 hours.
The Nikonos range of lenses includes two basic types: those which are terrestrial plane port lenses; and those designed purely for underwater work with specially designed, water-corrected optics. Nikon offered three types of lens: a 35-, 28-, and 80-mm long focus lens. The 35-mm lens is of excellent quality and, with this alone, the Nikonos is an extremely attrac- tive proposition for above water, sports, marine, and hostile environment work. If the glass port is exposed to water, dust, or mud, it can simply be wiped off. Under water, the lenses are less useful because of distortion problems.