Composite optical element and optical system including the same

An optical system, comprising:

• a composite optical element including a glass lens and a resin lens that are joined together,
• wherein the resin lens has an aspheric shape,
• wherein the optical system includes a first lens unit having a negative refractive power, a second lens unit having a positive refractive power, and a rear group that are arranged in that order from an object side to an image side, the rear group including at least one lens unit,
• wherein intervals between the lens units that are adjacent to each other vary during zooming, and
• wherein the composite optical element is included in the second lens unit, and
• wherein, when Nd is a refractive index of the resin lens, vd is an Abbe number of the resin lens, and θgF is a partial dispersion ratio of the resin lens, the following inequalities are satisfied:
• 1.900<Nd+(0.014×vd)<2.045
• 30.0<vd<35.0
• 0.6200<θgF+(0.0024×vd)<0.6900.

An optical system comprising:

• a composite optical element including a glass lens and a resin lens that are joined together,
• wherein the resin lens has an aspheric shape,
• wherein the optical system includes a first lens unit having a negative refractive power, a second lens unit having a positive refractive power, a third lens unit having a negative refractive power, and a rear group that are arranged in that order from an object side to an image side, the rear group including at least one lens unit,
• wherein intervals between the lens units that are adjacent to each other vary during zooming,
• wherein the composite optical element is included in the third lens unit, and
• wherein, when Nd is a refractive index of the resin lens, vd is an Abbe number of the resin lens, and θgF is a partial dispersion ratio of the resin lens, the following inequalities are satisfied:
• 1.900<Nd+(0.014×vd)<2.045
• 30.0<vd<35.0
• 0.6200<θgF+(0.0024×vd)<0.6900.

An imaging apparatus comprising:

• an optical system;
• and
• an image pickup device that receives an image formed by the optical system,
• wherein the optical system includes:
• a composite optical element including a glass lens and a resin lens that are joined together,
• wherein the resin lens has an aspheric shape,
• wherein the optical system includes a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, a third lens unit having a positive refractive power, and a rear group that are arranged in that order from an object side to an image side, the rear group including at least one lens unit,
• wherein intervals between the lens units that are adjacent to each other vary during zooming,
• wherein the composite optical element is disposed on the image side of the first lens unit, and
• wherein, when Nd is a refractive index of the resin lens, vd is an Abbe number of the resin lens, and θgF is a partial dispersion ratio of the resin lens, the following inequalities are satisfied:
• 1.900<Nd+(0.014×vd)<2.045
• 30.0<vd<35.0
• 0.6200<θgF+(0.0024×vd)<0.6900.