A display includes a source that establishes an exit pupil of far field content, a reconvergent sheet disposed along an optical axis to receive light of the far field content, the reconvergent sheet being configured to reconverge the far field content in position space, a reflective surface disposed along the optical axis for reflection of light of the position space back through the reconvergent sheet after reflection off of the reflective surface to re-form the exit pupil of the far field content, and a splitter disposed along the optical axis between the source and the reconvergent sheet and configured to redirect light exhibiting the re-formed exit pupil in a direction offset from the optical axis.

A display includes a source that establishes an exit pupil of far field content, a reconvergent sheet disposed along an optical axis to receive light of the far field content, the reconvergent sheet being configured to reconverge the far field content in position space, a reflective surface disposed along the optical axis for reflection of light of the position space back through the reconvergent sheet after reflection off of the reflective surface to re-form the exit pupil of the far field content, and a splitter disposed along the optical axis between the source and the reconvergent sheet and configured to redirect light exhibiting the re-formed exit pupil in a direction offset from the optical axis.

An optical system which forms an optical image on an image pickup element, comprising in order from an object side, a first lens unit having a positive refractive power, which includes a plurality of lenses, a stop, and a second lens unit which includes a plurality of lenses, wherein the first lens unit includes a first object-side lens which is disposed nearest to an object, and the second lens unit includes a second image-side lens which is disposed nearest to an image, and the first lens unit includes a negative lens, and a positive lens which is disposed on the object side of the negative lens, and the following conditional expressions are satisfied:
1.1(15)
0.08<NA(16)
1.0<WD/BF(19)
0.5<2(WDtan(sin.sup.1NA)+Y.sub.obj)/.sub.s<4.0.(20)

An optical system which forms an optical image on an image pickup element, comprising in order from an object side, a first lens unit having a positive refractive power, which includes a plurality of lenses, a stop, and a second lens unit which includes a plurality of lenses, wherein the first lens unit includes a first object-side lens which is disposed nearest to an object, and the second lens unit includes a second image-side lens which is disposed nearest to an image, and the first lens unit includes a negative lens, and a positive lens which is disposed on the object side of the negative lens, and the following conditional expressions are satisfied:
1.1(15)
0.08<NA(16)
1.0<WD/BF(19)
0.5<2(WDtan(sin.sup.1NA)+Y.sub.obj)/.sub.s<4.0.(20)

A lens system includes a first lens array assembly including a first plurality of cells, each cell of the first plurality of cells configured to exhibit a pair of first Fourier transform lenses, and a second lens array assembly including a second plurality of cells, each cell of the second plurality of cells configured to exhibit a pair of second Fourier transform lenses. The first Fourier transform lenses have a first pitch. The second Fourier transform lenses have a second pitch differing from the first pitch. The first and second lens array assemblies are positioned relative to one another along an optical axis of the lens system such that a Fourier transform of light from an object is developed at a plane between the first and second lens array assemblies and an image of the object is provided at an image conjugate distance from the second lens array assembly.

A control apparatus (125) includes an acquirer (125d) configured to acquire first information relating to a peak position of a spatial frequency that an image pickup optical system transmits for each spatial frequency, and a processor (125e, 125f, 125g) configured to calculate second information relating to a first evaluation band used for processing of image pickup signals and a second evaluation band used for processing of focus detection signals, the processor is configured to calculate third information relating to a weighting for each spatial frequency, and the processor is configured to calculate correction information of focus detection based on the first, second, and third information.

A control apparatus (125) includes an acquirer (125d) configured to acquire first information relating to a peak position of a spatial frequency that an image pickup optical system transmits for each spatial frequency, and a processor (125e, 125f, 125g) configured to calculate second information relating to a first evaluation band used for processing of image pickup signals and a second evaluation band used for processing of focus detection signals, the processor is configured to calculate third information relating to a weighting for each spatial frequency, and the processor is configured to calculate correction information of focus detection based on the first, second, and third information.

A single focal length lens system includes, in order from an object side to an image side, a first lens unit having positive optical power and a second lens unit including a lens element that moves in a direction of an optical axis with respect to an image surface in focusing from an infinity in-focus condition to a close-object in-focus condition. The first lens unit includes an aperture diaphragm and a lens element A located on the object side of the aperture diaphragm. A lens element B having positive optical power and a lens element C having negative optical power are located on the image side of the aperture diaphragm. Abbe numbers of the lens elements A, B, and C to the d-line and partial dispersion ratios of the lens elements A, B, and C for the g-line and the F-line satisfy a predetermined relation.

A single focal length lens system includes, in order from an object side to an image side, a first lens unit having positive optical power and a second lens unit including a lens element that moves in a direction of an optical axis with respect to an image surface in focusing from an infinity in-focus condition to a close-object in-focus condition. The first lens unit includes an aperture diaphragm and a lens element A located on the object side of the aperture diaphragm. A lens element B having positive optical power and a lens element C having negative optical power are located on the image side of the aperture diaphragm. Abbe numbers of the lens elements A, B, and C to the d-line and partial dispersion ratios of the lens elements A, B, and C for the g-line and the F-line satisfy a predetermined relation.

A lens system includes a first lens array assembly including a first plurality of cells, each cell of the first plurality of cells configured to exhibit a pair of first Fourier transform lenses, and a second lens array assembly including a second plurality of cells, each cell of the second plurality of cells configured to exhibit a pair of second Fourier transform lenses. The first and second lens array assemblies are positioned relative to one another along an optical axis of the lens system such that light diverging from an object at a plane disposed at an object conjugate distance from the first lens array assembly reconverges at an image plane after passing through the first and second lens array assemblies. The image plane is disposed at an image conjugate distance from the second lens array assembly in accordance with the object conjugate distance.