An optical apparatus includes: a first optical system configured to guide light from a first area on a first plane to a second plane, the second plane being a pupil plane of the first optical system relative to the first plane; a second optical system disposed between the second plane and a third plane, the second plane being a pupil plane of the second optical system relative to the third plane; a first reflective member that is disposed on a first optical path at an entrance side of the first optical system and that has a first reflective surface that is swingable; and a second reflective member that is disposed on a second optical path between the first optical system and the second optical system and that has a second reflective surface that is swingable.

A changing system for a microscope includes multiple afocal enlargement changing modules of different enlargement levels that are optionally introducible into an infinite beam path running along an optical axis of the microscope. Each of the enlargement changing modules contain a light deflection system. The light deflection systems are designed to adjust the path length of the infinite beam path passing through the respective enlargement changing module in such a way that all of the enlargement changing modules, regardless of the different enlargement levels of the enlargement changing modules, map an exit pupil of a lens of the microscope onto the same location along the optical axis.

A camera system of a mobile device includes: a sensor module disposed in a first body connected to a rotation member of the mobile device; and a lens module disposed in a second body connected to the rotation member. When the first body and the second body are rotated with respect to the rotation member to overlap each other, optical axes of the sensor module and the lens module correspond to each other and are operated as a common camera system, and the common camera system provides a first photographing mode and a second photographing mode with different viewing angles based on two focuses generated by a first geometry phase lens included in the lens module.

A varifocal lens includes a first phase plate and a second phase plate which are rotatable relative to each other about an optical axis. The first phase plate includes a plurality of first phase conversion elements, the second phase plate includes a plurality of second phase conversion elements, and the plurality of first phase conversion elements and the plurality of second phase conversion elements are arranged so that light transmitted through the first phase plate and the second phase plate is focused on different positions on the optical axis depending on a relative rotational displacement between the first phase plate and the second phase plate.

A varifocal lens includes a first phase plate and a second phase plate which are rotatable relative to each other about an optical axis. The first phase plate includes a plurality of first phase conversion elements, the second phase plate includes a plurality of second phase conversion elements, and the plurality of first phase conversion elements and the plurality of second phase conversion elements are arranged so that light transmitted through the first phase plate and the second phase plate is focused on different positions on the optical axis depending on a relative rotational displacement between the first phase plate and the second phase plate.

A digital microscope system comprises an imaging device configured to generate digital image data representing a target region of an object, the target region being determined by a changeable setting of the imaging device; and a controller configured to generate monitor image data corresponding to the digital image data generated in accordance with the setting, the monitor image data being configured to be displayed as a monitor image; wherein the controller is further configured to change the setting in response to a user input; and wherein the controller is further configured to compensate for a delay in updating the monitor image data in accordance with the changed setting by storing the digital image data generated in accordance with the unchanged setting in response to the user input and generating simulation monitor image data by performing digital image processing on the stored digital image data taking into account the changed setting, the simulation monitor image data being configured to be displayed as a simulation monitor image during the delay.

An optical system mount arrangement includes a stop, a mount for an optical element, and an electromagnet. The mount has a first position and a second position, the mount abutting the stop in the first position and the mount spaced apart from the stop in the second position. The electromagnet is fixed relative to the stop and is arranged to exert a holding force when the mount is in the first position. Optical systems, vehicles carrying optical systems, and methods moving optical elements in optical systems are also described.

An optical system mount arrangement includes a stop, a mount for an optical element, and an electromagnet. The mount has a first position and a second position, the mount abutting the stop in the first position and the mount spaced apart from the stop in the second position. The electromagnet is fixed relative to the stop and is arranged to exert a holding force when the mount is in the first position. Optical systems, vehicles carrying optical systems, and methods moving optical elements in optical systems are also described.

An extender lens changes a focal length of an entire lens system after replacement to a longer focal length side than a focal length of a master lens by replacing a part of the master lens with the extender lens. The extender lens consists of, in order from an object side to an image side, a first lens group, and a negative second lens group. The first lens group is a lens group that has a positive refractive power as a whole and has a shortest focal length among lens groups consisting of one lens component or a plurality of consecutively arranged lens components. The extender lens satisfies a predetermined conditional expression.

The imaging optical system forms a first intermediate image at a position conjugate to the magnification side imaging surface and a second intermediate image at a position closer to a reduction side than the first intermediate image on an optical path and conjugate to the first intermediate image. The imaging optical system consists of a first optical system, a second optical system, and a third optical system in order from a magnification side to the reduction side along the optical path. The imaging optical system is configured to be telecentric on the reduction side. The imaging optical system satisfies predetermined conditional expressions.