| 摘要 |
PROBLEM TO BE SOLVED: To obtain an ultraviolet wide-angle lens which has a small F number and a wide field angle and secures a space where plural ND filters, polarizing filters, etc., that are put in and out are arranged between lenses and is excellent in image forming performance by composing the lens of two lens groups which meet specific requirements shown by inequalities. SOLUTION: This lens consists of a 1st lens group G1 with negative refracting power and a 2nd lens group G2 with positive refracting power in order from an object side. The 1st negative lens group G1 consists of a 1st lens element L1 and a 2nd lens element L2 in order from the object side. The 2nd positive lens group G2 consists of a 3rd lens element - a 10th lens element L10 in order from the object side. And, the ultraviolet wide-angle lens consisting of the 1st lens group G1 and 2nd lens group G2 meets the two conditions of 1.86<|f1/fT|<1.89 and 3.00<|f2/fT|<3.22. Here, f1 and f2 are the focal lengths of the 1st and 2nd lens groups G1 and G2 and fT is the focal length of the whole system.
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