If you are a collector of pre 1900 cameras and related photographica, there's no doubt you are aware of Prosch shutters. Not only are these shutters items of immense beauty, but their Rube Goldberg-like designs are something to marvel at.
The story of the Prosch shutters really begins in 1839 with George W. Prosch and Samuel F.B. Morse. Prosch worked for Morse as his instrument maker, including working on Morse's telegraph. Prosch's shop was located in the basement of Morse's building located at 142 Nassau Street in New York City. When Morse became aware of the Daguerreotype process, he immediately requested Prosch, in late 1839, to build him a camera so he could experiment with the newly discovered process. That camera currently resides with the National Museum of American History at the Smithsonian (shown below).
George W. Prosch would go on to become a Daguerreotype artist as would his sister, Charlotte. Charlotte was one of the earliest and best known female Daguerreian artists. In fact, many members of the Prosch family had connections to the photographic industry.
"George Prosch, born in 1812, was the oldest of the children. He became a manufacturer of scientific instruments, and was a master worker in his line, which included chronometers, electric batteries, picture taking- apparatus and the like. He claimed that with a camera of his own invention he took the first daguerreotype in America. He also alleged that he was entitled to much of the credit that went to Professor S. F. B. Morse for the invention of the telegraph, the mechanical work being all his. Thomas Edison learned his trade with George Prosch. He (George) had his shop in Coytesville, New Jersey, where he spent the last twenty years of his life in seclusion, on account of an infirmity of his wife. He had two sons — Frederick and Cyrus. Fred became a school teacher. Cyrus took up his father's business, opening a shop in New York City, where he is said to have worked out many improvements in the photograph business."
Cyrus N. Prosch (1849-1920), would indeed follow in his father's footsteps as an instrument maker. In 1882, he patented a telegraph key, and then in late 1883 built a working version of his first model shutter which he filed a patent for in January 1884. The shutter was originally known as the "Prosch Instantaneous Shutter" but eventually called, the Eclipse. The February 1884 issue of Anthony's Photographic Bulletin ("APB"), first mentions the existence of this item.
Then, in the March 1884 issue of APB, a full drawing and description of the shutter is published.
Feb. 1884 APB
The full patent for the shutter can be found here. It's also interesting to note that Prosch assigned the patent to the E.H.&T Anthony company.
By late 1884 / early 1885, Prosch had brought another model shutter to market, the so called Duplex. While the Eclipse was fixed to the front of an existing lens, the Duplex shutter would sit between lens groups of a chosen lens, typically a rapid rectilinear or symmetrical lens. The "duplex" feature of this shutter was that it could be used to take instantaneous or timed exposures. The supplied lens' own apertures were used when fitted to this shutter.
In an 1885 issue of The Philadelphia Photographer, there is a brief mention of the Duplex and its features.
1885 Advertisement for the Eclipse and Duplex shutters:
Note that the Duplex allowed for changing speeds via a combination of setting a tensioned spring located on the back of the shutter and how fast or slow one would squeeze the pneumatic rubber bulb. The fastest speed allowed for was about 1/10 second. This particular version of the Duplex was filed for patent in December 1885 and issued in November 1886.
Here is an example of the first version of Prosch's Duplex shutter. Images courtesy of Scott Bilotta.
Prosch would continue in late 1886 and in early 1887 to make small modifications and improvements to the Duplex. One improvement was offering, as an option, rotary stops to be part of the shutter. This would allow for the ability to easily change apertures and do away with separate stops the lens may have had. Another improvement was having the option of a "Silent Time function" which allowed the user to quietly self-set the shutter to shoot a timed setting. Lastly, was the addition of "slow instantaneous attachments" which helped control speeds more effectively rather than soley relying on the pressure of the bulb release. These changes also precipitated the tension spring moving to the front face of the shutter. This made it far more simple to adjust speeds and one didn't need to remove the shutter from the camera to adjust it. During this transition phase from about late 1886 until early 1887, the Duplex was first marketed as the "Improved Duplex" as shown below in a book published in January 1887. Early models were marked "Patent Appl'd For" while later models were engraved with the patent date. From about mid-1887 on, the Duplex would be marketed as the "Triple Improved Duplex" to highlight the three added features of stops, silent time and slow speed control."
Note: "Improved Duplex"
Note "Patent Applied For" (missing some parts). Pre Nov. 1886 model
Later version with Patent date engraved and installed rotary stops
Two different tension springs were supplied with the Duplex shutters - a "weak" and a "strong" spring. These would further expand the range of speeds available to the photographer. The July 29, 1887 issue of The Photographic Times, featured an article by someone testing speeds on their Duplex shutter.
Although a bit hard to read, using the "strong" spring in notch 4, speeds of 1/240 second were obtained.
By the summer of 1887, the Duplex achieved its final form and was called the "Triple Improved Duplex" and would remain in this configuration for the rest of its product life. Note however, that the silent time function (which added an air cylinder on the left of the shutter) and the rotary stops were still options.
Based on the number of advertisements for the Duplex from about 1885 until the end of the century, coupled with the number of extant Duplex shutters, it's safe to day this shutter sold very well. Despite that, however, one can find numerous mentions of "shutter bounce" and double exposures caused by the Duplex shutter. One lengthy and complicated article on the subject is found in the June 16, 1888 issue of The Philadelphia Photographer which is shown below:
The Duplex would continue to be sold through the end of the century, but that didn't stop Prosch from bringing more shutter models to the marketplace. In 1888, he brought the Prosch Rapid shutter to market. This model featured speeds from 1/100 to 1/1600 or so claimed an article in Wilson's Photographic magazine in its May 16, 1891 issue. It was a bit of a specialty shutter as it only featured instantaneous speeds and was recommended for use at race tracks and athletic competitions.
Prosch Rapid Shutter
In early 1889, Prosch brought out his Triplex shutter, a further improvement on the Duplex. Whereas the Duplex was known for its two main functions of instantaneous speeds and timed settings, the Triplex was so named for its three functions: quick instantaneous speeds up to 1/250; slow instantaneous speeds from 1/50 to 1/4 and the ability to take timed exposures.
Also brought to market in 1889, were the Duplex and Triplex Stereoscopic shutters and Duplex and Triplex Detective shutters.
Duplex Stereoscopic Shutter
Triplex Stereoscopic Shutter - Courtesy of Ebay User Jerolyn-2
In 1892, Prosch brought out his Athlete shutter which featured speeds to 1/300 or 1/400 second depending on the size. Prosch later added an Athlete Special model which produced speeds up to 1/600 second. An example and line drawing are shown below.
Athlete Special Shutter - Image Courtesy Misterken on Flickr
In an issue of The American Annual of Photography for 1894, published in late 1883, Prosch advertised a "Nouveau" shutter. Other than this brief mention, I find no other references for this shutter.
In 1893, Prosch began offering the Triplex in an Aluminum version which reduced the shutter's weight.
Aluminum version of the Triplex
In late 1893 / early 1894 the Triplex was further improved (description of changes shown below). Note that 4 tension springs were now being supplied with the Triplex to assist in achieving an even greater number of shutter speeds.
Note the changes in hardware and the repositioning of the Prosch company engraving between the earlier Triplex and the Improved Triplex.
And, if that wasn't enough, in 1894 Prosch made a Columbian Triplex shutter that was made for Hand and Roll film cameras.
Curiously, in one of Scovill's late catalogues, I found the reference below to a Model 1896 Improved Triplex shutter. It's not entirely clear to me if this differs from the improvements that were made in 1894 - especially since the line drawing differs a bit (although those can be unreliable sources).
It took until 1903 for Prosch to bring out his final shutter models, the Diaplane I and II. The article below published in 1903 thoroughly describes these new shutters. The patent for this model was not filed until 1905 and was issued in 1906.
Diaplane I - Image Courtesy Milan Zahorcak
Diaplane II - Image Courtesy Milan Zahorcak
In late 1902 / early 1903, Prosch also brought out an "Athlete-Triplex" model shutter. This was designed for hand (and film) cameras specifically and had a safety shield so the shutter could be cocked without exposing the film during that process. Note that the article states that all Prosch shutters are now fitted with iris diaphragms. The patent was filed in October 1902 and issued April 1903.
In July of 1906, an article was published in Camera Craft magazine announcing the sale of the Prosch company to two employees of the original company. Cyrus N. Prosch would spend the rest of his life living in Fort Lee, NJ, his birthplace, until his passing in 1920. The Prosch company went on to focus on flash powder lamps (which it added to its product line in the 1890's) and eventually battery driven and electrified flash products. The last advertisement I am able to find for the company was from 1921.
Louis Prosch Jr (b. 1858), whose father immigrated from Germany in 1850, obviously related to Cyrus Prosch, worked for many years as a brassworker for the company. On March 10, 1891, Louis was awarded patent # 447,902 (patent filed for in Aug. 1890), for a front mounted, rotary shutter. For unknown reasons, this shutter would be sold by C.E. Hopkins as the "Pneumo Shutter."
Image Courtesy Ebay user Jerolyn-2
A "Prosch" shutter was sold a few years ago that I am unable to identify. It appears to be simple, Duplex-like and probably dates before 1888. If you can identify this model, I'd like to hear from you. This is the only image available of this item.
Corrections, additions and additional information on Prosch shutters is welcome. Email me.