There are two basic types of glass plate negatives: collodion wet plate and gelatin dry plate. Wet plate negatives, invented by Frederick Scoff Archer in 1851, were in use from the early 1850s until the 1880s.  Using glass and not paper as a foundation, allowed for a sharper, more stable and detailed negative, and several prints could be produced from one negative. The photographer, however, was on the clock: the wet plate process, including exposure and processing, had to happen before the collodion emulsion dried. Collodion wet plate negatives characteristically have uneven emulsion coatings, and thick glass with rough edges. Occasionally, the photographers thumb will be visible on the corner or edge of the plate (from holding the plate while coating it in the collodion emulsion).

Silver gelatin-coated dry plate negatives, on the other hand, were usable when dry and thus more easily transported, and required less exposure to light than the wet plates. Invented by Dr. Richard L. Maddox and first made available in 1873, dry plate negatives were the first economically successful durable photographic medium. Dry plate negatives are typically on thinner glass plates, with a more evenly coated emulsion. Dry plate glass negatives were in common use between the 1880s and the late 1920s.

Benjamin A. Gifford Photographs, circa 1885-circa 1920
The Benjamin A. Gifford Photographs consist of photographs made by Gifford during his career as a photographer in Portland and The Dalles, Oregon. The images depict Native Americans, primarily of the Columbia Plateau region; the Columbia River and the Historic Columbia River Highway; Central and Eastern Oregon; Gifford Family members; and many unidentified individuals and groups. Gifford arrived in Oregon and worked first in Portland until 1895, when he opened a studio in The Dalles. He returned to Portland in 1910. Images from this collection have been digitized and are available in Oregon Digital. Glass negatives comprise the majority of the collection, and can be found in Boxes 17 - 58.

Horticulture Department Photographs, 1900-1980
The Horticulture Department Photographs consist of images taken and assembled by horticulture faculty for teaching and research and depict a variety of horticultural topics as well as the Oregon Agricultural College campus. The Department of Horticulture and Botany was established in 1888; a separate Horticulture Department formed in 1909. Images from this collection have been digitized and are available in Oregon Digital. Glass negatives can be found in Boxes 07 - 29.

Oregon State University Historical Photographs, 1868-1980
The Oregon State University Historical Photographs Collection is an artificial collection comprised of images gathered from multiple sources. The collection provides visual documentation for a number of noteworthy individuals, activities and events dotting the history of Oregon State University for nearly one century. Images from this collection have been digitized and are available in Oregon Digital. Glass plate negatives can be found in Boxes 15 - 34.

Walter R. Baker Photographs, circa 1863 - circa 1930
The Walter R. Baker Photographs consists of images taken or collected by Baker during and soon after his student years at Oregon Agricultural College (OAC). The collection includes images of campus buildings and students as well photographs of buildings in and near Salem, Oregon, and of the Portland, Oregon, waterfront. Baker attended OAC from 1904 to 1909; he earned a BS in Electrical Engineering in 1908 and completed graduate work in 1909 leading to designation as an Electrical Engineer. Images from this collection have been digitized and are available in Oregon Digital. Glass negatives can be found in Boxes 05 - 15.

E. E. Wilson Photographic Collection, circa 1855-1953
The E. E. Wilson Photographic Collection consists of images of Wilson, a Corvallis native and Oregon Agricultural College (OAC) alum, as well as his family and friends, the OAC campus, Corvallis, and other locations around the Pacific Northwest. The collection also includes images of the 1915 Panama Pacific Exposition in San Francisco and photos of Siletz tribe members. Glass plate negatives can be found in Boxes 06 - 26.

Sydney Trask Photograph Collection, 1871-1932
This personal collection of photographs taken (and assembled) by Sydney Trask includes many notable images from the 1890s through 1910s of Oregon Agricultural College buildings, campus views, classrooms, and laboratories. Trask attended Oregon Agricultural College in 1894-1896. Before coming to Corvallis in 1894, he was a photographer for the railroad in eastern Oregon; in the late 1890s, he had a photographic studio in Corvallis. Images from this collection have been digitized and are available in Oregon Digital. The majority of the collection is comprised of glass plate negatives, housed in Boxes 02 - 13.

Herman T. Bohlman Photograph Collection, circa 1890-1928
The Herman T. Bohlman Photograph Collection consists of images taken and assembled by Bohlman documenting bird species and his travels, primarily in the Pacific Northwest.  Bohlman was a lifelong friend and collaborator of renowned ornithologist, naturalist, and conservationist William L. Finley.   Many of the photographs are available online in the Oregon Digital collection Reuniting Finley and Bohlman. Glass plate negatives can be found in Boxes 01 - 09, and Box 15.

Oregon State University Military Photographs Collection, 1875-1975
The Oregon State University Military Photographs Collection consists of images of military education and cadets at Oregon State from various sources and time periods. Individual images include portraits and group shots of military cadets and officers, as well as reviews, formations, training, and instructional materials. Photographs are arranged chronologically by historical era. Courses in military science have been taught at Oregon State since the early 1870s. Images from this collection have been digitized and are available in Oregon Digital. Glass negatives can be found in Boxes 05 - 09.

College of Agricultural Sciences Photographs, 1892-2001
The College of Agricultural Sciences Photographs were taken or assembled by College staff and faculty to document the Oregon State University's academic and research programs in agriculture; Branch Experiment Stations in Oregon; faculty, students, and alumni; international programs; and special events, conferences, and workshops. The bulk of the images are b/w prints and color slides; the collection also includes nitrate and glass negatives; some film negatives; and a few color prints. Images from this collection have been digitized and are available in Oregon Digital. Sub-series 1 in the collection, consists of 63 plate glass negatives; these negatives can be found in Boxes 03 - 05.

Herbarium Photographs, 1904-1963
The Herbarium Photographs were made or assembled by curators of the Herbarium and students in the Department of Botany and Plant Pathology. The images depict a variety of subjects including Pacific Northwest species of plants and trees, the Oregon Agricultural College greenhouses, botany research and teaching, and logging operations. Images from this collection have been digitized and are available in Oregon Digital. Glass negatives in the collection can be found in Boxes 02 - 03.

Buildings Photographic Collection, 1880-2002
The Building Photographs collection documents Oregon State University buildings, grounds, and facilities as well as a limited number of other notable buildings in Corvallis. The collection also includes approximately 20 line drawings of buildings located on other Oregon University System campuses. Images from this collection have been digitized and are available in Oregon Digital. There are 25 glass negatives in the collection: image #2, 37-45, 142, 149, 171, 255, 1104-1113, and 1251.

Gerald W. Williams Glass Negatives Collection, circa 1910
The Gerald W. Williams Glass Negatives Collection consists of eight glass negatives of the Oregon coast assembled and acquired by Williams due to his avocational interest in the history of the Pacific Northwest region.  The photographer is not identified.  Gerald Williams worked for the U.S. Forest Service from 1979 to 2005 as a sociologist (1979-1998) and historian (1998-2005). Images from this collection have been digitized and are available in Oregon Digital.

• Glass negatives in Oregon Digital