Imaging lens and imaging apparatus

An imaging lens consisting of six lenses in four groups,

• wherein a first lens, a first cemented lens composed of a second lens and a third lens cemented together, a fourth lens, and a second cemented lens composed of a fifth lens and a sixth lens cemented together are arranged in this order from an object side, and
• wherein the first lens has a plano-concave shape or a meniscus shape with a concave image-side surface, and negative refractive power, and
• wherein one of the second lens and the third lens in the first cemented lens has positive refractive power and an other one of the second lens and the third lens has negative refractive power, and
• wherein the fourth lens has positive refractive power, and an object-side surface of the fourth lens is a flat surface or a surface with a curvature radius, and an absolute value of the curvature radius of the object-side surface of the fourth lens being greater than an absolute value of a curvature radius of an image-side surface of the fourth lens, and
• wherein one of the fifth lens and the sixth lens in the second cemented lens has positive refractive power and an other one of the fifth lens and the sixth lens has negative refractive power, and
• wherein a stop is arranged between the first cemented lens and the fourth lens, and
• wherein the following formulas (1) through (3) are satisfied:
• 1.80<Bf/f≦2.533 (1);
• 0.15<N1n−N1p≦0.239 (2);
• and
• 0.0<ν1n−ν1p<10.0 (3), where
• Bf:
• a back focus of the imaging lens (a length in air),
• f:
• a focal length of the imaging lens,
• N1n:
• a refractive index of the negative lens in the first cemented lens for d-line,
• N1p:
• a refractive index of the positive lens in the first cemented lens for d-line,
• ν1n:
• an Abbe number of the negative lens in the first cemented lens for d-line, and
• ν1p:
• an Abbe number of the positive lens in the first cemented lens for d-line.