I claim the ornamental design for a digital still camera, as shown and described.
FIG. 1 is a front and right side perspective view of a digital still camera of the present invention;
FIG. 2 is a rear and left side perspective view thereof;
FIG. 3 is a front view thereof;
FIG. 4 is a rear view thereof;
FIG. 5 is a top view thereof;
FIG. 6 is a bottom view thereof;
FIG. 7 is a left side view thereof; and,
FIG. 8 is a right side view thereof.
The broken lines shown represent unclaimed subject matter and form no part of the claimed design. The outermost circle shown in FIGS. 1 and 3 with dash lines defines the bound of the claimed subject matter. Applicants disclaim any features shown within the circle. Also, the rectangular shape shown in FIGS. 2 and 4 with dash lines defines the bound of the claimed subject matter. Applicants disclaim the area within the rectangle.