| 摘要 |
PROBLEM TO BE SOLVED: To obtain a front type teleconverter lens usable for a single lens reflex camera, small in size and light in weight by providing a front group which includes a negative lens and a positive lens and whose composite focal length is a positive value, and a rear group which is constituted of a combined lens constituted of the negative and the positive lenses and whose composite focal length is a negative value, and satisfying a specified condition. SOLUTION: This tele converter lens is used by being attached to the object side of a master lens M, and constituted of the front group which includes at least one negative lens and at least one positive lens and whose composite focal length is the negative value, and the rear group of the combined lens which is constituted of the negative lens and the positive lens from the object side, and whose composite focal length has the negative value; and satisfied the condition of 0.34<dFR/Σd<0.55. Provided thatΣd is defined as a distance between the front and the rear groups, andΣd is defined as the thickness of the converter lens on an axis. Consequently, both group can compensate the chromatic aberration by themselves, assemblability is good, the diameter of a lens can be made small, the thickness of an edge can be secured, and the thickness of the positive lens of the combined lens can be made thin.
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