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Daguerre, in describing his invention in 1839, said that in Paris, the exposure time could be anything from 3 to 30 minutes depending on the month of the year, time of the day and whether conditions. In the very beginning photography could absolutely live without a real shutter. Removing and replacing the lens cap manually was perfectly convenient. Later, when the exposure time dropped to seconds or fractions of one second, having something providing more control became a real need. That was about 1875 when the silver-bromide gelatin plates were introduced. If you want to see a time line with the most important processes in the photographic image making click here.
This Obturateur CL Guerry uses a simple flap covered with black velvet and it is activated with a inflation bulb. The external rubber parts were missing so I adapted hose and bulb using replacement parts for sphygmomanometer (that stuff used to measure blood pressure). The internal one is original (at least looks very old) and it is surprisingly still working. The movement is very smooth and silent with no significant lens/camera vibration being introduced. Here you can see how it is attached to the lens and the metal parts on the top are for flash synchronization. It is possible to see it closing in the video when the lens is fully open. It was certainly intended for flash powder.
Here is how it fits on camera lens. But it can also be adapted inside the camera as shown in the picture below. In the catalog for the 1900 Universal Exhibition it is written: The shutter from Mr. Guerry (1880 and 1881) which is still in use mostly inside photo studios, has the advantage of working with no noise inside the camera, the sitter does not realize it and the operator can therefore get a favorable expression without fearing some nervous and involuntary movements, almost inevitable, when the model hears or sees the objective being opened.
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In this illustration we can see a valve used for holding the flap open during framing and focusing. It could also work as a B setting. I guess the shortest exposure time one can get with this shutter must be around 1/4 of a second. That is what I used in a well lit room with 100 ASA film and a Petzval lens (approximately f1:4) on the portraits at the bottom of this page.
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Advertising in a Kodak book from 1904.
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Mention to the Guerry shutter in the catalog for the Universal Exhibition in Paris 1900. That was in introductory notes accounting for a brief history of this kind of devices. The Guerry shutter it is mentioned as still in use but, by 1900, it was already a museum piece as well. The illustration shows one with double flap.
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