The Diamond Shutter received its name, based on the shape of the shutter's diaphragm. This was detailed in The Photographic News: A Weekly Record of the Progress of Photography, Volume 34, 1890, under a meeting of the Society of Amateur Photographers of New York that noted "Mr. Wm. T. Gregg preferred a shutter operating between the lenses, and exhibited a model of his diamond shutter, called such because of the diamond-shaped diaphragm it made. Very few shutters worked quicker than the 1/100th part of a second, and the average about the 1/50th of a second."

The following historical excerpt comes from noted collector and historian Jerry Spiegel's description for the example featured here. I had the pleasure of meeting Jerry, purchasing numerous items from his collection over several years and learned much from him during the conversations we had:

"William Theodore Gregg, an optician, came from Ireland in the early 1840's and established a business in New York City. By 1843 he was advertising optical equipment including telescopes, surveying instruments, and other photographic goods. He was a contemporary of all the great American photographic names of that time, including Scovill Mfg. Co., C.C. Harrison, August Semmendinger and Holmes, Booth & Haydens. Sometime in 1882, due to the retirement or death of Gregg, the assets of the firm were acquired by W. & D. Mogey, telescope makers from New Jersey, who continued the business under the Gregg name for another ten years or so. It's unusual that after 39 years of activity plus another ten years with Mogey, so few of Gregg's products survive today, unless the photographic side of the business was always secondary and low volume. This example of Gregg's Diamond Shutter, equipped with a 12" lens and a serial number of 102, was probably marketed immediately following the acquisition. The lens is unmarked, but considering its age, probably a Rapid Rectilinear. The dimensions at the shutter are 4" diameter and 1/4" thick at the lens, 2" in diameter and 3-3/4" long. The glass diameter is about 1-1/2", making this an f8 +/- lens. Of interest is the fact that there is no light control provision, Waterhouse or wheelstops and no diaphragm. This lens was wide open at f8 for all work."

Gregg was selling shutters as early as 1886, as seen in an advertisement in Anthony's Photographic Bulletin, Volume XVII for that year. The ad mentions new cameras, lenses and shutters.

Gregg was also marketing shutters in 1887, in an advertisement in Photographic Mosaics for that year. The ad mentions "Gregg's Instantaneous Shutter" and "Time Shutters". These are both different and believed earlier than the Diamond Shutter, since several Time and Instantaneous shutters illustrated in Anthony's The International Annual and Anthony's Photographic Bulletin, Volume I, July, 1888 show them to be totally different designs than the Diamond.

Per the Collection of Historical Scientific Instruments, Harvard University, the firm was continued by his son William T. Gregg Jr. Optician, after 1887, the year of his death.

Assuming Harvard's information to be correct, William T. Gregg (presumed Jr.) was still living in 1901, per a testimonial in Photo Era for January, 1901, wherein a print had been received from "Wm. T. Gregg" produced from one of his lenses.

No patents for the Diamond Shutter's design have been found so far.

Gregg's advertisements state that he marketed the Blair line, and with that connection, some speculation has arisen as to whether cameras bearing his name were manufactured by him or by others. Photographic advertisements for Gregg have been found from 1886-1893, and based upon what's known so far, the Diamond was probably produced between 1890 and 1893.

This example is marked "Wm. T. Gregg, 102, New York". Other than one other seen on eBay, having serial number 104 and missing all of its external mechanism, this is the only example of Gregg's Diamond Shutter I've ever encountered.

With just two known examples to go by, a brief production run and both having 3-digit serial numbers, no doubt relatively few were made. Little is seen today of Wm. T. Gregg's products, and as American shutters go, the Diamond can be considered very rare.

Wm. T. Gregg billhead, 1892

From Scovill's The American Annual of Photography and Photographic Times Almanac for 1893....note the diamond-shaped diaphragm