Nikonos IV-A
In 1980, Nikon introduced the Nikonos IV-A. The Nikonos group of cameras was derived from the Calypso, a French underwater camera. With the IV-A, Nikon introduced a new design rather than a derivative interaction of the Calypso.
The Calypso was a French camera starting in 1961. In 1963, Nikon licensed the Calypso and released the Nikonos. There was also a Nikonos II and a Nikonos III, all were slight variations of the original. With the IV-A, Nikon finally put out a Nikon-designed Nikonos. Major changes included a more traditional shutter release and hinged film back. Also, added was a light meter and aperture priority mode.
My take:
The original Nikonos was a marvel for the ability to provide a dive camera but at the cost of a double wall construction that made changing film a real chalenge. The IV-A improves on the previous to be come a much more usable camera. It is still zone focus and still a brick of a camera but finaly a more user friendly brick.
Not knowing the condition of the O rings, I used the IV-A as a land camera but did expose it to a very rainy day. Not the most intuitive land camera but if you going out in bad weather or diving, a usable camera. Just check your O-ring before you submerge. This Nikonos could work as an adventure camera because it is a tank, but it is also heavy and bulky so if you not getting wet,it is overkill.
Lens: Nikon Nikkor35mm f2.5
Film: Fujicolor Superia Xtra Expired
Links:
http://www.brokencamera.club/blog/nikonos
https://www.cameramanuals.org/nikon_pdf/nikonos_iv-a.pdf
https://www.mir.com.my/rb/photography/companies/nikon/htmls/models/htmls/nikonos45.htm
https://imaging.nikon.com/history/chronicle/history-nikonos/index.htm
https://www.pacificrimcamera.com/rl/01144/01144.pdf
https://casualphotophile.com/2018/04/17/nikon-nikonos-retrospective-review-film-camera-blog/