HIGH RESOLUTION LENS FOR LARGE-SIZED PHOTOGRAPH

PROBLEM TO BE SOLVED: To provide a lens almost at a diffraction limit at the F number of not only 1:22 but also 1:16 and 1:11 by forming a positive meniscus lens from the glass of a refractive index not more a specified value and an Abbe number larger than a specified value and maintaining the magnitude of a specified order among respective lens elements. SOLUTION: The positive meniscus lenses L3 and L4 are respectively formed from partially abnormally dispersed glass and formed from the glass of the refractive index of not more 1.63 and the Abbe number νe larger than 63. Then, between the respective lens elements, the magnitude of the order of r1 =0.20...0.26f', r2 =larger than f', r3 =0.17...0.23f', r4 =0.35...0.65f', r5 =0.40...1.00f', r6 =0.30...0.57f', r7 =0.18...0.26f', r8 =0.11...0.18f', r9 =larger than f' and r10 =0.17...0.23f' is mutually maintained.