Photographic optical system and image pickup apparatus having the same

An image pickup apparatus comprising:

• a photographic optical system 1;
• and
• a solid-state image sensor configured to receive an image formed by the photographic optical system,
• the photographic optical system comprising along an optical axis therof and arranged in order from an object side to an image side;
• a first lens unit having a positive refractive power;
• a second lens unit having a positive or negative refractive power;
• and
• a third lens unit having a positive or negative refractive power, focusing being performed by moving the second lens unit in a direction parallel to the optical axis,
• wherein at least one diffractive optical element and at least one optical element made of solid material are provided closer to the object side than a position where a paraxial chief ray intersects the optical axis, and
• wherein, when a focal length obtained by only a diffraction component of the diffractive optical element is denoted by fDOE, a focal length of the optical element made of solid material is denoted by fNL, a focal length of the first lens unit is denoted by f1, and a relative anomalous partial dispersion of a material forming the optical element made of solid material is denoted by ΔθgFNL, the following conditions are satisfied:
• 10<fDOE×fNL/f12<600
• 0.0272<ΔθgFNL<0.3000.