Optical imaging system

An optical imaging system comprising:

• a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens sequentially disposed in ascending numerical order along an optical axis from an object-side surface of the first lens toward an imaging plane of the optical imaging system,
• wherein the first to sixth lenses are the only lenses disposed between the object-side surface of the first lens and the imaging plane and are each constituted by a single lens, and
• the following conditional expression is satisfied:
• 11≤TTL/IMG_HT
• where TTL is a distance along the optical axis from the object-side surface of the first lens to the imaging plane, and IMG_HT is one-half of a diagonal length of the imaging plane.

An optical imaging system comprising:

• a first lens, a second lens, a third lens, a fourth lens, and a fifth lens sequentially disposed in ascending numerical order along an optical axis from an object-side surface of the first lens toward an imaging plane of the optical imaging system,
• wherein the first to fifth lenses are the only lenses disposed between the object-side surface of the first lens and the imaging plane,
• the following conditional expression is satisfied:
• 11≤TTL/IMG_HT
• where TTL is a distance along the optical axis from the object-side surface of the first lens to the imaging plane, and IMG_HT is one-half of a diagonal length of the imaging plane,
• the first lens has a non-circular shape when viewed in a direction of the optical axis,
• an image-side surface of the first lens has an effective radius that varies from a minimum effective radius that is a short axis effective radius L1S2es in a first direction perpendicular to the optical axis to a maximum effective radius that is a long axis effective radius L1S2el in a second direction perpendicular to the first direction and perpendicular to the optical axis, and
• the following conditional expression is satisfied:
• 0.8<L1S2es/L1S2el<1.0.