The Nikonos II, introduced in May 1968 and produced until 1975, was the second iteration of Nikon's amphibious 35mm camera system. While it maintained the core design of the original Nikonos, it introduced several practical mechanical refinements for better usability in and out of the water.
Key Improvements Over Nikonos I
Rewind Crank: The most notable external change was the addition of a fold-out film rewind crank, replacing the slower knob-style rewind used on the original model.
Hinged Pressure Plate: The internal film pressure plate was redesigned to be hinged and "pop-up," which simplified film loading compared to the previous fixed design.
Anti-Corrosion Coating: Internal parts were specifically coated to resist corrosion; if saltwater leaked in, the camera's internals could often be rinsed with fresh water and dried to restore functionality.
Visual Markings: The "II" designation was added next to the viewfinder window, and the lens re-introduced white lines (reminiscent of the original Calypso) to clearly indicate which knob controlled aperture versus focus.
Weight Reduction: The camera's weight was reduced by approximately 50 grams compared to the first model.