Merkel Minerva Tropical c1923
During the early 1920's , the camera industry was flourishing and among the various aggressive marketing strategies was creation of exotic luxury models. Certainly there was a need for tropical models of MF and LF cameras, models that were built with resistant woods and brass or nickel plated hardware. However, among the tropical cameras produced were those built as much (perhaps more) for show than performance in tropical climes.
The 9x12 cm camera shown here is an Italian creation built around 1923 based on the Minerva tropical model from Merkel in Germany. This special model was sold by A. Trussardi in Milan and was equipped with a Rulex shutter and the highly unusual Koristka Sideran anastigmat lens. It had gold "splash" plated lens mount and front plate accented by gold plated vertically adjustable lens stand and hardware including a gold splash plated drop door plate. The case is polished mahogany with heavy brass fittings.
The camera bellows, optics and hardware are in original condition. The mahogany wood has been restored with an oil finish. Brass fittings are polished and unlaquered.
This camera differs only slightly from the Merkel Minerva model which was equipped with both a brilliant viewfinder and a direct simple wire frame viewfinder. The camera shown here has the brilliant viewfinder with ruby spirit level as well as a precision Newtonian viewfinder. The remaining parts of the camera including the brown leather bellows are identical to the Merkel Minerva 9x12cm tropical model.
The lens is highly unusual and rare. It was built by Francesco Koristka who founded his company in Milan in 1880. It is an f/4.5 105mm Anastigmat Sideran which was based upon the Zeiss Tessar under a license from Zeiss. Koristka built precision optical lenses and equpment until they were absorbed by Officina Galileo in 1929. The shutter is a Rulex and is also highly unusual because the Rulex shutters were of the highest quality during this period. They were not the same as the shutters designed and built in Japan by two well known German engineers, Neumann and Heilemann who first established a small factory in the Kansai area in Western Japan.
The Rulex shutter works smoothly from B to 1/300 sec. The rare F. Koristka Sideran lens is clean and only very light cleaning marks are evident. The gold plating was done using a "splash" technique on to a brass substrate producing a gold encrusted flat surfaces. It is largely intact but worn on the exterior as shown below.
This truly unique camera arrived in rather sad condition. However, it is now stabilized from further degeneration and partially restored without obliterating its well-earned marks of use during the past 85 years or so. The original leather case and film holders are included in the collection.