Zoom lens and imaging apparatus

A zoom lens comprising, in order from an object side to an image side:

• a first lens group that has a positive refractive power;
• a second lens group that has a negative refractive power;
• a third lens group that has a positive refractive power;
• and
• a fourth lens group that has a positive refractive power,
• wherein during zooming from a wide-angle end to a telephoto end, the first lens group is stationary relative to an imaging surface, and the second lens group is moved to the image side in an optical axis direction so as to decrease a space between the second lens group and the third lens group,
• wherein the third lens group includes, in order from the object side to the image side, a positive lens, a negative lens, and a cemented lens which has a positive refractive power and is formed of a positive lens positioned on the object side and a negative lens positioned on the image side, and
• wherein the following Conditional Expressions (2) and (3) are satisfied:
• 1.85<Ndg3_neg<1.95, and (2)
• 20.0<vdg3_neg<30.0, (3)
• where
• Ndg3_neg is a refractive index of glass of the negative lens, which is the second element from the object side in the third lens group, at the d-line, and
• vdg3_neg is an Abbe number of the glass of the negative lens, which is the second element from the object side in the third lens group, at the d-line.

An imaging apparatus comprising:

• a zoom lens;
• and
• an imaging device that converts an optical image, which is formed by the zoom lens, into an electrical signal,
• wherein the zoom lens includes, in order from an object side to an image side
• a first lens group that has a positive refractive power,
• a second lens group that has a negative refractive power,
• a third lens group that has a positive refractive power, and
• a fourth lens group that has a positive refractive power,
• wherein during zooming from a wide-angle end to a telephoto end, the first lens group is stationary relative to an imaging surface, and the second lens group is moved to the image side in an optical axis direction so as to decrease a space between the second lens group and the third lens group,
• wherein the third lens group includes, in order from the object side to the image side, a positive lens, a negative lens, and a cemented lens which has a positive refractive power and is formed of a positive lens positioned on the object side and a negative lens positioned on the image side, and
• wherein the following Conditional Expression (1) is satisfied:
• −0.95<fg3_neg/fg3<−0.5, (1)
• where
• fg3_neg is a focal length of the negative lens which is a second element from the object side in the third lens group, and
• fg3 is a focal length of the third lens group.

An imaging apparatus comprising:

• a zoom lens;
• and
• an imaging device that converts an optical image, which is formed by the zoom lens, into an electrical signal,
• wherein the zoom lens includes, in order from an object side to an image side
• a first lens group that has a positive refractive power,
• a second lens group that has a negative refractive power,
• a third lens group that has a positive refractive power, and
• a fourth lens group that has a positive refractive power,
• wherein during zooming from a wide-angle end to a telephoto end, the first lens group is stationary relative to an imaging surface, and the second lens group is moved to the image side in an optical axis direction so as to decrease a space between the second lens group and the third lens group,
• wherein the third lens group includes, in order from the object side to the image side, a positive lens, a negative lens, and a cemented lens which has a positive refractive power and is formed of a positive lens positioned on the object side and a negative lens positioned on the image side, and
• wherein the following Conditional Expressions (2) and (3) are satisfied:
• 1.85<Ndg3_neg<1.95, and (2)
• 20.0<vdg3_neg<30.0, (3)
• where
• Ndg3_neg is a refractive index of glass of the negative lens, which is the second element from the object side in the third lens group, at the d-line, and
• vdg3_neg is an Abbe number of the glass of the negative lens, which is the second element from the object side in the third lens group, at the d-line.