FIG. 1 is a perspective view of the top, front and left side of a convertible lens for single-lens reflex 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 view thereof;

FIG. 6 is a top plan view thereof;

FIG. 7 is a bottom plan view thereof;

FIG. 8 is a magnified section view of the grip thereof;

FIG. 9 is a cross-sectional view of the grip along the lines 9 — 9 ; and,

FIG. 10 is a cross-sectional view of the grip along the lines 10 — 10 .

The portions shown in broken lines are for illustrative purposes only and form no part of the claimed design.