OPTICAL SYSTEM AND IMAGE CAPTURING DEVICE

PROBLEM TO BE SOLVED: To provide a zoom optical system which is compact and light-weight, offers a large aperture and high imaging performance, and corrects well for aberration of rays in a wide range of wavelengths over an entire zoom range, and to provide an image capturing device having the same.SOLUTION: In order to solve the above mentioned problem, an optical system is provided, comprising a positive first lens group G1, negative second lens group G2, positive third lens group G3, positive fourth lens group G4, and positive fifth lens group G5 arranged in order from the object side. The third lens group G3 includes at least one positive lens and one negative lens, and is substantially configured with three or less lenses. When zooming from the wide-angle end to the telephoto end, distance between each pair of adjacent lenses is relatively altered while the first and third lens groups G1, G3 are kept stationary to satisfy the predetermined conditions.SELECTED DRAWING: Figure 1 【課題】本発明の課題は、小型化、軽量化を図りつつ、大口径で結像性能が高く、変倍域全域において広い波長域の光線を良好に収差補正することができる変倍光学系、及び当該変倍光学系を備えた撮像装置を提供することにある。【解決手段】上記課題を解決するため、物体側から順に配置される、正の第１レンズ群Ｇ１、負の第２レンズ群Ｇ２、正の第３レンズ群Ｇ３、正の第４レンズ群Ｇ４、及び、正の第５レンズ群Ｇ５から構成され、第３レンズ群Ｇ３は正レンズと負レンズとをそれぞれ少なくとも１枚含み、且つ、実質的に３枚以下のレンズから構成され、広角端から望遠端への変倍に際し、第１レンズ群Ｇ１及び第３レンズ群Ｇ３を固定し、各レンズ群間の距離を相対的に変化させ、所定の条件を満足することを特徴とする変倍光学系とする。【選択図】図１