An image capturing apparatus capable of executing autofocus by at least one of a phase difference detection method and a contrast detection method using an image signal obtained from a set focus detection region and from which an imaging optical system and a converter lens are detachable. The image capturing apparatus comprises: a conversion unit configured to convert aberration information indicating a spherical aberration of the imaging optical system based on a magnification and aberration information of the converter lens in a case where the converter lens is mounted; a calculation unit configured to calculate a correction value for correcting a difference between a result of the autofocus and a focus condition of a captured image; and a control unit configured to control a position of a focus lens based on the result of the autofocus that has been corrected using the correction value.

A converter lens (RCL) has a negative refractive power, which is disposed on an image side of a master lens (ML) to make a focal length of an entire system longer than that of the master lens alone. The converter lens comprises a most image-side lens element (LT) disposed closest to an image side in the converter lens, wherein the most image-side lens element has a lens surface having a convex shape toward an image side, a lens disposed closest to an image side in the converter lens has a positive refractive power, and mN<mP and 0.0≤LR2/AR2<1.0 are satisfied.

A method is provided for switching operation of a monitoring system from a first monitoring mode to a second monitoring mode. An overview image is presented when the monitoring system is in a first monitoring mode. A direction signal is received from a control means when the monitoring system is in the first monitoring mode. A camera is directed in an absolute direction indicated by the direction signal in accordance with a first camera control scheme. The monitoring system enters into a second monitoring mode in response to receiving the direction signal presenting a detailed image view captured by the camera when directed in the direction indicated by the direction signal. When in the second monitoring mode, a camera head of the camera is moved in response to control signals from the control means in accordance with a second control scheme.

A method is provided for switching operation of a monitoring system from a first monitoring mode to a second monitoring mode. An overview image is presented when the monitoring system is in a first monitoring mode. A direction signal is received from a control means when the monitoring system is in the first monitoring mode. A camera is directed in an absolute direction indicated by the direction signal in accordance with a first camera control scheme. The monitoring system enters into a second monitoring mode in response to receiving the direction signal presenting a detailed image view captured by the camera when directed in the direction indicated by the direction signal. When in the second monitoring mode, a camera head of the camera is moved in response to control signals from the control means in accordance with a second control scheme.

Apparatuses, systems, and methods for producing non-rotationally symmetric optical aberrations. Such aberrations may be created by a removable attachment that may be attached to another lens, such as a spherical lens. Aberrations that appear to reproduce an anamorphic effect may be produced, yet the underlying camera system may remain a spherical camera system, and the capture mode may remain non-anamorphic.

Apparatuses, systems, and methods for producing non-rotationally symmetric optical aberrations. Such aberrations may be created by a removable attachment that may be attached to another lens, such as a spherical lens. Aberrations that appear to reproduce an anamorphic effect may be produced, yet the underlying camera system may remain a spherical camera system, and the capture mode may remain non-anamorphic.

Provided are a rear converter lens and an imaging apparatus capable of achieving favorable optical performance and an appropriate back focal length with high magnification. The rear converter lens RCL consists of, in order from the object side, four lens-groups of positive, negative, negative, and positive lens-groups. In order from the object side, a first lens-group RG1 consists of a negative lens RL11 and a positive lens RL12, a second lens-group RG2 consists of a negative lens RL21 and a positive lens RL22, a third lens-group RG3 consists of a negative lens RL31, a positive lens RL32, and a negative lens RL33, and a fourth lens-group RG4 consists of a biconvex lens RL41 and a negative lens RL42. Here, 0.22<cf/f12<1 is satisfied, where f12 is a composite focal length of the first lens-group RG1 and the second lens-group RG2, and cf is a focal length of the rear converter lens RCL.

Provided are a rear converter lens and an imaging apparatus capable of achieving favorable optical performance and an appropriate back focal length with high magnification. The rear converter lens RCL consists of, in order from the object side, four lens-groups of positive, negative, negative, and positive lens-groups. In order from the object side, a first lens-group RG1 consists of a negative lens RL11 and a positive lens RL12, a second lens-group RG2 consists of a negative lens RL21 and a positive lens RL22, a third lens-group RG3 consists of a negative lens RL31, a positive lens RL32, and a negative lens RL33, and a fourth lens-group RG4 consists of a biconvex lens RL41 and a negative lens RL42. Here, 0.22<cf/f12<1 is satisfied, where f12 is a composite focal length of the first lens-group RG1 and the second lens-group RG2, and cf is a focal length of the rear converter lens RCL.

The present disclosure provides a projection apparatus. The projection apparatus includes: a light supply device, including an LED lamp and a collimator fly-eye lens, wherein lamp bodies of the LED lamp are arrayed and the LED lamp is capable of simultaneously emitting red, green, and blue light rays, and the collimator fly-eye lens is capable of collimating the light ray emitted by each of the lamp bodies; an optical path conversion device, configured to convert a direction of the light rays emitted by the light supply device; a DMD device, configured to process the light rays from the optical path conversion device and feed the processed light rays to the optical path conversion device; and a projection lens device; wherein the light rays transmitted by the optical path conversion device to the projection lens device to achieve image projection.

An optical device with switchable multiple lenses can be mounted on an electronic device through a connecting module, and provides finely-adjusted alignment with an image capturing lens in any position, and provides a zoom or wide-angle lens for the user to change the focal length and view field of the image. A light-filling/polarizing regulation module to fill light and eliminate unnecessary reflected light to avoid marginal diminishing effect of the image. The optical device includes a viewing device, a connecting module and a light-filling/polarizing regulation module, wherein the viewing device includes a lens module located in the housing and having at least two lenses through which an image captured by the image capturing lens is magnified. At least two lenses has the same lens power, or at least two lenses of different magnifications can be used with the switchable lens seat to obtain the effects of switching different lenses.