Lot of two (2) cased daguerreotypes 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. Two (2) sixth plate seated studio portrait tintypes. Philadelphia: John A. Keenan, ca. 1850s. Full leatherette case with photographer's imprint embossed in velvet pad. Inscription behind the plate identifies sitters as Marth Mauer Sliver, 4 years old (left) and Mary E. Sliver, 11 years old (right). With out-of-case original view. 

This plate presents a remarkable period copy of an original Mascher stereoscopic daguerreotype depicting two young sisters seated side-by-side in matching dresses. Rather than housing the portrait in a bulky stereoscopic viewing case, Keenan reproduced the client’s original stereo plate directly onto a standard sixth plate tintype, retaining the dual-oval format while allowing it to be housed in a conventional flat case. The included out-of-case view of the bare plate illustrates this process, clearly displaying the faint photographic trace of the original mat borders and margins.

[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. The Keenan copy plate is in very good condition with sharp definition.