Various embodiments disclosed herein include techniques for maintaining multiple cameras in focus on same objects and/or at same distances. In some examples, a subordinate camera may be configured to focus based on the focus of a primary camera. For instance, a focus relationship between the primary camera and the subordinate camera may be determined. The focus relationship may characterize the trajectory of the lens position of the subordinate camera with respect to the lens position of the primary camera. In various examples, the focus relationship may be updated.

A control apparatus includes a calculation unit configured to perform a focus detection by a phase difference detection method based on an image signal output from an image sensor, and to calculate a defocus amount, and a focus control unit configured to control a focus lens based on the defocus amount. When a predetermined condition is satisfied, the focus control unit changes a driving speed of the focus lens based on information on a luminance or contrast of the image signal. At least one processor or circuit is configured to perform a function of at least one of the units.

An image capturing terminal includes a first camera module, a second camera module, and a processing module. The first camera module and the second camera module are used for framing concurrently a same scene and for detection and analysis according to contrast ratios of different frames of images, in which a focus search range includes a first focus area and a second focus area that do not overlap each other. The processing module is used for controlling the first camera module to search for a focus in the first focus area and, at the same time, for controlling the second camera module to search for a focus in the second focus area, and for capturing focus information of either the first camera module or the second camera module, and is used for controlling, according to the focus information, the first camera module to capture an image at the focus point.

An automatic focus system for an optical microscope that facilitates faster focusing by using at least two cameras. The first camera can be positioned in a first image forming conjugate plane and receives light from a first illumination source that transmits light in a first wavelength range. The second camera can be positioned at an offset distance from the first image forming conjugate plane and receives light from a second illumination source that transmits light in a second wavelength range.

Provided is a control device that includes a calculation unit that calculates, on a basis of a result of capturing a subject image passed through a focus lens by using an imaging element including a plurality of phase difference detection regions, a focus position of each of the phase difference detection regions and a determination unit that determines a position of the focus lens on a basis of an average value of the focus positions of the phase difference detection regions calculated by the calculation unit and falling within a predetermined range from the focus position on an infinity side or macro side.

Various embodiments disclosed herein include techniques for maintaining multiple cameras in focus on same objects and/or at same distances. In some examples, a subordinate camera may be configured to focus based on the focus of a primary camera. For instance, a focus relationship between the primary camera and the subordinate camera may be determined. The focus relationship may characterize the trajectory of the lens position of the subordinate camera with respect to the lens position of the primary camera. In various examples, the focus relationship may be updated.

A control apparatus includes a first focus detector (255, 212) which performs focus detection by phase difference detection using a first sensor (254) that receives a light ray formed by an image capturing optical system, a second focus detector (204, 212) which performs the focus detection using a second sensor (201) that receives a light ray formed by the image capturing optical system, a calculator (212a) which calculates correction information corresponding to a difference between first and second signals from the first and second detectors, a memory (209) which stores the correction information, a controller (212b) which performs focus control based on the first signal in a first area and performs the focus control based on the second signal and the correction information in a second area, and an identifier (212) which identifies an object, and the memory stores the correction information for each object.

Various embodiments disclosed herein include techniques for maintaining multiple cameras in focus on same objects and/or at same distances. In some examples, a subordinate camera may be configured to focus based on the focus of a primary camera. For instance, a focus relationship between the primary camera and the subordinate camera may be determined. The focus relationship may characterize the trajectory of the lens position of the subordinate camera with respect to the lens position of the primary camera. In various examples, the focus relationship may be updated.

An automatic focus system for an optical microscope that facilitates faster focusing by using at least two cameras. The first camera can be positioned in a first image forming conjugate plane and receives light from a first illumination source that transmits light in a first wavelength range. The second camera can be positioned at an offset distance from the first image forming conjugate plane and receives light from a second illumination source that transmits light in a second wavelength range.

A focus adjustment device comprising: a first detector which detects a focused state by a contrast detection system; second detectors which detect a focused state by a phase difference detection system; and a control unit which controls the first detector and second detectors so as to detect the focused state by the second detectors when detecting the focused state by the first detector.