The techniques of this disclosure relate to actively selecting lenses for camera focus processes. Lenses to be used during camera assembly are chosen based on whether their pairing with a specific set of production components can satisfy focus performance criteria of end of line test. Test equipment may check the lenses by dry-fit aligning them to a particular set of production components. If minimum focus performance cannot be achieved, then a different set of lenses are used to with that set of production components to produce a final camera assembly. This way, because the lenses are actively selected during production to achieve satisfactory focus performance of the EOLT, each final camera assembly is more likely to pass the EOLT, thereby improving camera production output.

The techniques of this disclosure relate to actively selecting lenses for camera focus processes. Test equipment may check lenses by dry-fit aligning them to a particular set of production components. If minimum focus performance cannot be achieved, then the lenses go unused for a final camera assembly. In certain situations, the unused set of lenses is salvageable for use in another camera assembly. Advanced CMAT equipment may compute and apply a rotation for unused lenses to improve their focus performance the next time they are used in a final assembly. A maximum number of attempts to rotationally fix a set of lenses may be observed to avoid trying the same lenses again and again, possibly without ever having success. This way, because the lenses actively selected can also be rotated during production, final camera assemblies can be produced that are likely to pass the EOLT, and by minimizing waste.

A system and method of characterizing through-focus visual performance of an IOL using metrics based on an area under the modulation transfer function for different spatial frequencies at different defocus positions of the IOL. Also disclosed is a system and method of characterizing through-focus visual performance of an IOL using a metric based on an area under a cross-correlation coefficient for an image of a target acquired by the IOL at different defocus positions of the IOL.

A system for evaluating the modulation transfer function (MTF) of a device under test is provided. The system includes an image projector configured to provide light in a pattern representing a desired image. The system further includes a lens configured to direct the provided light toward the device under test as a collimated beam. An image analysis component calculates the MTF for the device under test from the at least one image taken at the device under test and the known characteristics of the image projector and the lens.

A method of determining a modulation transfer function (MTF) for an image includes receiving an image captured through the optical system, performing edge detection on columns or rows in the image to calculate a plurality of edge points, calculating a plurality polynomials to fit to the calculated edge points, each of the plurality of polynomials varying in degree, selecting a polynomial from the plurality of polynomials to represent the detected edge, and estimating the MTF based on the selected polynomial.

The invention relates to an apparatus (2) for detecting imaging quality of an optical system (4) with at least one lens (6) or lens group. The apparatus (2) includes an MTF measuring apparatus (10) for measuring a modulation transfer function at a plurality of field points in the field of view of the optical system (4), and a centering measuring apparatus (18) for measuring a centered state of the optical system (4).

A method of manufacturing a polymer film includes melting a resin, extruding the melted resin through a die to produce a polymer film, shaping the polymer film, cooling the polymer film, capturing an image of a test pattern through the polymer film, calculating a modulation transfer function value from the image, and adjusting a process parameter of the melting, the extruding, the shaping, or the cooling based on the calculated modulation transfer function value.

A camera testing system for determining performance of a camera comprising an imaging sensor and a lens, the system comprising a processing system comprising at least one processor and memory. The processing system may be configured to: control the camera to capture, using the imaging sensor, a first image through the lens of a target disposed at a first distance from the camera; determine a first modulation transfer function (MTF) value from the first image; control the camera to capture, using the imaging sensor, a second image through the lens of the target disposed at a second distance from the camera that is different from the first distance; determine a second MTF value from the second image; and determine performance of the camera based on the first MTF value, the second MTF value and a difference between the first MTF value and the second MTF value.

Described is camera focusing including lens centration estimation using variable focal length phased metalenses. Camera modular alignment and test (CMAT) equipment checks the modular transfer function (MTF) performance of lenses and an image sensor. The CMAT equipment positions a variable focal length phased metalens between the lenses and the image sensor. The metalens includes multiple segments that provide a variable focus depending on distance and angle from boresight of the image sensor. By measuring optical characteristics of the lenses at two opposing segments of the metalens, defocusing effects and a lens centration tilt vector can be computed. Repositioning the lenses to align the centration tilt vector with the boresight of the image sensor improves the MTF performance. A final camera assembly with lenses in precise alignment with the image sensor can be produced, which may improve production output by increasing pass rate at an end of line tester.

For testing the imaging performance of an optical system, a test target is positioned at an object plane of the optical system, and illuminated to generate an image beam. One or more images of the test target are acquired from the image beam. From the imaging data acquired, Edge Spread Functions at a plurality of locations within the test target are calculated. A model of Point Spread Functions is constructed from the Edge Spread Functions. Based on the Point Spread Functions, a plurality of imaging performance values corresponding to the plurality of locations are calculated. The imaging performance values are based on Ensquared Energy, Encircled Energy, or Strehl ratio.