The ornamental design for an instantcamera, as shown and described.
FIG. 1 is a front-left perspective view of an instant camera, showing the new design;
FIG. 2 is a front-right perspective view thereof;
FIG. 3 is a front view thereof;
FIG. 4 is a top view thereof; and,
FIG. 5 is a bottom view thereof.
The broken lines and the portion shown in light grey within the broken lines in the drawings illustrate portions of the instant camera that form no part of the claimed design.