Lot of three (3) images, including two (2) cased daguerreotypes and one (1) uncased tintypes featuring different takes on "double expposures." The lot includes:

1. Quarter plate seated studio portrait stereoscopic daguerreotype. [Philadelphia]: John F. Mascher, ca. 1853-1855. Full leatherette case with stereoscopic viewer featuring publisher's imprint. 

Patented by Philadelphia optician John F. Mascher on 8 March 1852, this twin stereo-pair exposure captures an attractive young woman in an off-the-shoulder dark evening gown, lace mitts, and pendant drop earrings, resting her arm against a draped studio chair. When viewed through the raised binocular lenses, the slightly offset vantage points fuse into a striking, lifelike three-dimensional portrait. Intact, fully functioning Mascher stereo cases remain highly collectible milestones of early photographic optical design.

2. One (1) sixth plate daguerreotype. [Philadelphia]: John A. Keenan, ca. 1850s. Full leatherette case with photographer's imprint embossed in velvet pad. An inscription behind the plate identifies the subjects as Martha Mauer Sliver, 4 years old (left) and Mary E. Sliver, 11 years old (right).

This piece represents a deliberate double-portrait composition: two distinct poses captured side-by-side on a single daguerreotype plate to showcase each sibling individually within the same case. Keenan operated his fashionable gallery at 248 South Second Street specifically between 1852 and 1857 (notably mentoring his brother-in-law, celebrated frontier photographer William Bell), where he was a favorite of high society. 

3. One (1) sixth plate copy tintype of plate 2, above. Unknown artist, ca. 1850s - 1860s. 

This plate presents a remarkable period copy of the original Keenan daguerreotype of the Silver sisters. Rather than housing the portrait in a bulky dual viewing case, a photographer later reproduced the client’s original plate directly onto a standard sixth plate tintype, retaining the dual-oval format while allowing it to be housed in a conventional flat case. 

[Daguerreotype, Stereoscopic Daguerreotype, Mascher's Patent, Mascher's Improved Stereoview, Stereoview, John F Mascher, 3D Photography, Binocular Vision, Quarter Plate, Sixth Plate, Dual Portrait, Sisters, Keenan, John Keenan, Philadelphia Photography, Cased Images, 19th Century Photography]

Overall condition is very good. The Mascher stereoscopic plate retains crisp focus and rich tonal depth across both portraits. Some handling "noise" can be seen in the leftmost plate. Both the Keenan original and its copy plate remain in very good condition, both with sharp definition.