The focal spot size is typically determined by the numerical aperture of the used objective lens.

To achieve cryo-FM, a trade-off must be made between the temperature and performance of objective lens.

The 42-mm objective lens gathers lots of light for a clear view at dusk or in shadows.

In this approach, no objective lens is required and, beneficially, the complexities of conventional OR-PAM systems can be greatly relieved.

Galileo's design featured a convex objective lens and a concave ocular lens, which represented an improvement over Lippershey's original design.

By sharing the same laser source and objective lens, intrinsically registered photoacoustic and fluorescence images are acquired in a single scan.

Although special objective lens was designed in many current cryo-FM approaches, the unavoided frosting and ice contamination are still affecting the efficiency of cryo-CLEM.

The telescope and compound microscope, which has an objective lens and an eyepiece lens for producing a wide range of magnifications, were further developed.

The compound microscope (using an ocular and an objective lens in series) was invented in the 1590s, some four decades before their birth.

Grade III was applied to tumors (n = 339) for which the POR fully occupied the microscopic field of a 40x objective lens.