Zoom lens having magnification factors in the range of 6.5x to 14x for micrographic applications

A variable focal length lens systems for use in micrographic projectors and printers comprising lenses according to the following Table:

• ______________________________________ RADIUS ELE- OF THICK- MENT SURFACE CURVATURE NESS SEPARATION ______________________________________ S1 19.146 12 7.60 S2 -21.208 14 1.50 S3 28.652 16.75 S4 -216.043 16 6.80 S5 -13.501 18 2.00 S6 -33.758 0.20 S7 27.871 20 4.90 S8 -354.527 4.075 -17.336 S9 -65.515 22 2.30 S10 28.767 24 4.48 S11 -312.853 2.30 S12 -29.315 26 2.50 S13 Plano ______________________________________ INDEX ELE- OF DECEN- MENT TOLERANCE REFRACTION TRATION TILT ______________________________________ 12 0.050 1.69350 0.012 0.046 14 0.050 1.78590 0.050 16 0.100 1.48749 0.012 0.086 18 0.100 1.83500 0.050 20 0.100 1.48749 0.025 0.070 22 0.100 1.77250 0.035 0.059 24 0.100 1.78470 0.050 26 0.100 1.64000 0.025 0.054 ______________________________________
• wherein the radius of curvature is expressed as positive for surfaces convex to the direction of light and negative for surfaces concave to the direction of light, the radii, thickness, separation, tolerances for the thicknesses of the elements and decentration are expressed in millimeters and tilt is expressed in degrees.