![](data:image/png;base64,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)
(4)式右辺の逆数νdをとり、正の値を考えると
CF
d
dnn
n
1
-(5)
この値をアッベ(Abbe)数と呼び、硝材などの光学媒質の波長に依存した性質を表わす定数である。
当然、アッベ数が大きくなると、分散は小さくなる。本連載、前回第 22 回に掲載させていただいた
硝子表 7)の横軸にはこのアッベ数がとってある。
これまでの導出過程よりご理解いただける通り、あくまでもアッベ数は可視域の d 線を中心とし
た色収差の検討に用いられるべき値であることに留意が必要である。
さて、(5)式を(3)式に代入し計算すると
d
f
f
-(6)
となり、焦点距離もアッベ数も限られた値の範囲(極端に大きかったり、小さかったりしない)にある
ので、一種類の硝子より成り立つ薄肉単レンズにおいては、必ず焦点距離の色収差が存在するこ
とが理解できる。
3.参考文献
1) 油 大作:通信講座テキスト“光学技術の基礎講座”(トリケップス、東京、1993)
2) 小倉敏布:写真レンズの基礎と発展(朝日ソノラマ、東京、1995)
3) 高野栄一:レンズデザインガイド(写真工業出版社、東京、1993)
4) 辻内順平:光学概論Ⅰ(朝倉書店、東京、1979)
5) 松居吉哉:結像光学入門(JOEM、東京7)1988)
6) 村田和美:光学(サイエンス社、東京、1979)
7) http://www.ohara-inc.co.jp/jp/product/optical/opticalglass/data.html