Inverse telescopic wide angle lens

An inverse telescopic wide angle lens comprising:

• a diaphragm;
• a front lens group of an integral positive or negative refractive power, positioned in the object side in front of said diaphragm and having a first lens group of a negative refractive power including a negative lens of which an image-side air-contacting surface is formed as an aspherical surface concave to the image side, and a second lens group of a positive refractive power positioned between said first lens group and said diaphragm;
• and
• a rear lens group of an integral positive refractive power, positioned behind said diaphragm and having plural lenses;
• wherein said negative lens in said first lens group is so constructed that the absolute value of the refractive power of said concave surface on the optical axis is larger than that of the refractive power of the surface at the object side on the optical axis, that the curvature of said concave surface decreases monotonously with the distance from the optical axis, and that the form of said concave surface of said negative lens at the image side, when represented by an equation:
• x=Cy.sup.2 /{1+(1-.kappa.C.sup.2 y.sup.2).sup.1/2 }+C.sub.4 y.sup.4 +C.sub.6 y.sup.6 + . . .
• defining the axial distance x from the peak point of a curve constituting said aspherical surface as a function of the distance y of said curve from the optical axis, with a curvature C at said peak point of the curve, a conical constant .kappa. and aspherical constants C.sub.4, C.sub.6, . . . , satisfies a condition -5<.kappa.<0.5;
• and
• said aspherical surface satisfies a condition:
• 0. 8<.vertline.h.sub.p /r.sub.A .vertline.<1.5
• wherein r.sub.A is the paraxial radius of curvature of said aspherical surface and h.sub.p is the height, from the optical axis, of the crossing point of the principal ray at the maximum image angle on said aspherical surface.