The ornamental design for a stereoscopicviewer, as shown and described.
FIG. 1 is a rear perspective view of a stereoscopic viewer showing our new design;
FIG. 2 is a front perspective view of a stereoscopic viewer showing our new design;
FIG. 3 is a rear elevational view thereof;
FIG. 4 is a front elevational view thereof;
FIG. 5 is a right side elevational view thereof;
FIG. 6 is a left side elevational view thereof;
FIG. 7 is a top plan view thereof; and,
FIG. 8 is a bottom plan view thereof.
The broken lines in the drawings illustrate optional portions that do not form an essential part of the claimed design. While the drawings illustrate one or more example embodiments, it should be understood that according to other example embodiments that should be considered to be within the scope of the present disclosure, it is contemplated that any illustrated solid lines (or portions thereof) can be converted to broken lines and that any illustrated broken lines (or portions thereof) can be converted to solid lines to claim or disclaim portions, components, or sub-components of the designs shown. It is further contemplated that shading can be added or removed to claim or disclaim the corresponding surfaces.