Description

BAUSCH & LOMB Iris Diaphram Shutter in a makeshift camera studio. Patent Jan. 6, 1891 Information on lens: Baush & Lomb Opt Co. 19956 New York, Rochester NY, Chicago Don't miss out on the opportunity to own this vintage camera and add it to your collection today. In 1890, this new model was introduced as " The Diaphragm Shutter ", which is how it's mostly referred to in factory advertisements. As a shutter option in many camera ads though, it's mostly referred to as an "Iris Diaphragm" which is the term used by most collectors today. The "diaphragm" name originates from the shutter's leaves which also serve as the aperture by advancing to a preset opening as the shutter is tripped. The Diaphragm Shutter is easily identified by the two vertically mounted valves on the front of the shutter, one to release the action pneumatically and the other to regulate speed, together with its unique linkage. Speeds are selected by rotating the dial at top front, with the aperture opening being set by rotating the dial at the rear. The lever below the speed dial is used to select either time or instantaneous exposures. The exposure is then made after cocking the lever on top between the speed and aperture dials, using either the manual release or pneumatically with a squeeze bulb attached. Some Diaphragm Shutters are not equipped with a manual release, but you'll find them on about half of those encountered today. I've referred to this shutter as The Diaphragm Shutter - Model of 1891 , adding the "Model of 1891" to distinguish it chronologically among Bausch & Lomb's earliest shutters. The Diaphragm was designed in 1890 (patent filed July 2, 1890) with the earliest examples probably being produced later that year prior to the issuance of Patent No. 444,083 on January 6, 1891. The shutter's design was shared by Edward Bausch, George Hommel and Andreas Wollensak. In 1899, Andreas Wollensak, together with his brother John and financier Stephen Rauber, went on to form Rauber & Wollensak : Source: U.S. Patent and Trademark Office More information can be found at this link: https://www.antiquephotographica.info/BAUSCH%20&%20LOMB%20OPTICAL%20COMPANY%20-%20THE%20DIAPHRAGM%20SHUTTER-MODEL%20OF%201891%20WEB%20PAGE%201-18-2020.htm Note: Dusty. Condition is unknown. Lens is untested. Sold as is.