The ornamental design for a camera, as shown and described.
FIG. 1 is a top, front and left side perspective view of a camera showing my new design;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a rear elevational view thereof;
FIG. 4 is a left side elevational view thereof;
FIG. 5 is a right side elevational thereof;
FIG. 6 is a top plan view thereof; and,
FIG. 7 is a bottom plan view thereof.
The broken lines are for environmental purposes only and form no part of the claimed design. The shade lines in the figures show contour and not surface ornamentation. The diagonal lines in the FIGS. 1-3 represent a reflective surface.