The present invention provides a zoom lens that is compact in general and has an F-number to implement brightness even in the telephoto end side, and an imaging apparatus equipped with the zoom lens. The zoom lens includes, in order from an object side: a first lens group having positive refractive power; a second lens group having positive refractive power; a third lens group having negative refractive power; and a fourth lens group having positive refractive power. At the time of zooming from the wide-angle end state to the telephoto end state, the third lens group moves so that the distance between the second lens group and the third lens group increases, and the distance between the third lens group and the fourth lens group decreases.

An optical system (ZL(1)) comprises a plurality of lens groups including a first focusing lens group (G2) and a second focusing lens group (G4) that are disposed side by side on an optical axis, and the second focusing lens group (G4) is disposed at a position closer to an image surface than the first focusing lens group (G2). The first focusing lens group (G2) has positive refractive power, and moves toward an object along the optical axis from focusing on an infinite-distance object to focusing on a short-distance object. The second focusing lens group (G4) moves toward the image surface along the optical axis from focusing on the infinite-distance object to focusing on the short-distance object. The optical system (ZL(1)) satisfies the following conditional expression. 020<F1/F2<0.50 where F1 is the lateral magnification of the first focusing lens group at the time of focusing on the infinite-distance object, and F2 is the lateral magnification of the second focusing lens group at the time of focusing on the infinite-distance object.

The present invention provides a zoom lens that is compact in general and has an F-number to implement brightness even in the telephoto end side, and an imaging apparatus equipped with the zoom lens. The zoom lens includes, in order from an object side: a first lens group having positive refractive power; a second lens group having positive refractive power; a third lens group having negative refractive power; and a fourth lens group having positive refractive power. At the time of zooming from the wide-angle end state to the telephoto end state, the third lens group moves so that the distance between the second lens group and the third lens group increases, and the distance between the third lens group and the fourth lens group decreases.

An optical system for a microscope for imaging an object includes: a telescope system having an optical correction unit, which is adjustable in order to correct a spherical imaging aberration, and having a zoom optical unit, which is adjustable in order to adapt a magnification of the telescope system to a ratio of two refractive indices, one of which is assigned to an object side and an other of which is assigned to an image side, within a predetermined magnification range. The telescope system is telecentric over an entire magnification range both with respect to the object side and with respect to the image side by the zoom optical unit contained in the telescope system.

A lens interchangeable digital camera includes an image sensor in which a subject image is formed on an imaging surface through an imaging optical system including a zoom lens and a sensor movement type shake correction mechanism that performs a sensor movement operation of moving the image sensor in a direction to cancel a shake. A zoom operation determination unit determines whether or not a zoom operation in which the zoom lens moves is being performed. In a case where the zoom operation determination unit determines that the zoom operation is being performed, an operation deciding unit prohibits a shift operation which is at least a part of a sensor movement operation which is allowed while the zoom operation is stopped.

The present disclosure is directed to an optical system internally having an intermediate imaging position MI that is conjugate with both of a magnification conjugate point on a magnification side and a reduction conjugate point on a reduction side, the optical system including: a first positive lens group GP1 including a plurality of lens elements and positioned on the magnification side with respect to the intermediate imaging position; a second positive lens group GP2 including a plurality of lens elements and positioned between the first positive lens group GP1 and the intermediate imaging position M1; and a negative lens group GN including a plurality of lens elements and positioned on the reduction side with respect to the intermediate imaging position MI, wherein, during focusing, the first positive lens group GP1 and the negative lens group GN move in an optical axis direction, and the second positive lens group GP2 is stationary.

The present disclosure is directed to an optical system internally having an intermediate imaging position that is conjugate to a magnification conjugate point on a magnification side and a reduction conjugate point on a reduction side, respectively, the optical system including: a magnification optical system having a plurality of lens elements, positioned on the magnification side with respect to the intermediate imaging position; and a relay optical system having a plurality of lens elements, positioned on the reduction side with respect to the intermediate imaging position, wherein a first lens element located closest to the magnification side among the plurality of lens elements in magnification optical system is an aspherical lens having a negative power, the optical system satisfies the conditions (1) to (3).