US Patent 8000035 Wide-angle lens, optical apparatus, and method for focusing

Providing a wide-angle lens having high optical performance, an optical apparatus using thereof, and a method for focusing the wide-angle lens. The lens including, in order from an object, a first lens group G1 having negative refractive power, a second lens group G2 having positive refractive power, and a third lens group G3 having positive refractive power. Upon varying focusing from an object locating at infinity to an object locating at close distance, the first lens group G1 is fixed, and the second lens group G2 and the third lens group G3 are moved to the object side. The second lens group G2 includes a negative lens component L21 to the most object side, and a given conditional expression is satisfied.