Simple lens


Lens consisting of a single simple element.

- Simple lens

11 related topics



Transmissive optical device which focuses or disperses a light beam by means of refraction.

A biconvex lens
Lenses can be used to focus light
Light being refracted by a spherical glass container full of water. Roger Bacon, 13th century
Lens for LSST, a planned sky surveying telescope
Types of lenses
The position of the focus of a spherical lens depends on the radii of curvature of the two facets.
A camera lens forms a real image of a distant object.
Virtual image formation using a positive lens as a magnifying glass.
Images of black letters in a thin convex lens of focal length f are shown in red. Selected rays are shown for letters E, I and K in blue, green and orange, respectively. Note that E (at 2f) has an equal-size, real and inverted image; I (at f) has its image at infinity; and K (at f/2) has a double-size, virtual and upright image.
An aspheric biconvex lens.
Close-up view of a flat Fresnel lens.

A simple lens consists of a single piece of transparent material, while a compound lens consists of several simple lenses (elements), usually arranged along a common axis.

Camera lens

Optical lens or assembly of lenses used in conjunction with a camera body and mechanism to make images of objects either on photographic film or on other media capable of storing an image chemically or electronically.

Different kinds of camera lenses, including wide angle, telephoto and speciality
The zoom lens assembly of the Canon Elph
Different apertures on the same lens.
How focal length affects photograph composition: adjusting the camera's distance from the main subject while changing focal length, the main subject can remain the same size, while the other at a different distance changes size.
A tilt/shift lens, set to its maximum degree of tilt relative to the camera body.
Collapsible Leica rangefinder lens

While in principle a simple convex lens will suffice, in practice a compound lens made up of a number of optical lens elements is required to correct (as much as possible) the many optical aberrations that arise.

Fresnel lens

Type of composite compact lens developed by the French physicist Augustin-Jean Fresnel for use in lighthouses.

First-order rotating catadioptric Fresnel lens, dated 1870, displayed at the Musée national de la Marine, Paris. In this case the dioptric prisms (inside the bronze rings) and catadioptric prisms (outside) are arranged to concentrate the light from the central lamp into four revolving beams, seen by sailors as four flashes per revolution. The assembly stands 2.54 metres tall and weighs about 1.5 tonnes.
1: Cross-section of Buffon/Fresnel lens. 2: Cross-section of conventional plano-convex lens of equivalent power. (Buffon's version was biconvex. )
Close-up view of a flat Fresnel lens shows concentric circles on the surface
Makapuu Point Light
Cape Meares Lighthouse; first-order Fresnel lens
A plastic Fresnel lens sold as a TV-screen enlarging device
The Fresnel lens used in the Sinclair FTV1 portable CRT TV, which enlarges the vertical aspect of the display only
Inchkeith lighthouse lens and drive mechanism
Optical landing system on US Navy aircraft carrier USS Dwight D. Eisenhower
Cross-section of a first-generation Fresnel lighthouse lens, with sloping mirrors m,n above and below the refractive panel RC (with central segment A). The design was later improved by replacing the mirrors with reflective prisms to reduce losses. If the cross-section in every vertical plane through the lamp L is the same (cylindrical symmetry), the light is spread evenly around the horizon.
First-order group-flashing Fresnel lens, on display at the Point Arena Lighthouse Museum, Point Arena Lighthouse, Mendocino County, California. The three dioptric panels (inside the brass rings) and three catadioptric panels (outside) are partly split in two, giving three double-flashes per rotation.
First-order lens
Close-up of a second-order lens
Third-order lens (St. Simons Island Light)
Fourth-order lens (Sekizaki Lighthouse, Oita, Japan)
Fifth-order lens (Jones Point Light)
Sixth-order lens (Ponce de Leon Inlet Light)

Spherical: A spherical Fresnel lens is equivalent to a simple spherical lens, using ring-shaped segments that are each a portion of a sphere, that all focus light on a single point. This type of lens produces a sharp image, although not quite as clear as the equivalent simple spherical lens due to diffraction at the edges of the ridges.

Crown glass (optics)

Type of optical glass used in lenses and other optical components.

An achromatic doublet, which combines crown glass and flint glass.

The dispersions of the glasses partially compensate for each other, producing reduced chromatic aberration compared to a singlet lens with the same focal length.

Doublet (lens)

An achromatic doublet
An old Carl Zeiss Tessar camera lens with four elements, comprising two doublets. The front doublet is air-gapped and divergent; the rear doublet is glued and convergent. This arrangement was better at correcting spherical and chromatic aberrations and astigmatism than previous lens designs.

In optics, a doublet is a type of lens made up of two simple lenses paired together.


Type of lens that is attached to a variety of optical devices such as telescopes and microscopes.

A collection of different types of eyepieces.
A 25 mm Kellner eyepiece
Simulation of views through a telescope using different eyepieces. The center image uses an eyepiece of the same focal length as the one on the left, but has a wider apparent field of view giving a larger image that shows more area. The image on the right has the same apparent field of view as the center eyepiece but has a shorter focal length, giving the same true field of view as the left image but at higher magnification.
The Plössl, an eyepiece with a large apparent field of view
Examples (from left to right) of 2" (51 mm), 1.25" (32 mm), and 0.965" (24.5 mm) eyepieces.
The eye relief. 1 Real image 2 - Field diaphragm 3 - Eye relief 4 - Exit pupil
Negative lens
Convex lens
Huygens eyepiece diagram
Ramsden eyepiece diagram
Kellner eyepiece diagram
Plössl eyepiece diagram
Orthoscopic eyepiece diagram
Monocentric eyepiece diagram
Erfle eyepiece diagram
König eyepiece diagram
RKE eyepiece diagram
Nagler type 2 eyepiece diagram
Nagler type eyepieces

Elements are the individual lenses, which may come as simple lenses or "singlets" and cemented doublets or (rarely) triplets.


The Lensbaby 2.0
Image created with a Lensbaby selective focus lens.
Lensbaby Spark
Lensbaby Scout installed with Fisheye Optic
Lensbaby Composer with its aperture disks
Example of selective focus

Lensbaby is a line of camera lenses for DSLR and mirrorless cameras that combine a simple lens with a bellows or ball and socket mechanism for use in special-effect photography.

Aspheric lens

Lens whose surface profiles are not portions of a sphere or cylinder.

An aspheric biconvex lens.
Cross section of the Schmidt corrector plate, a common aspheric lens
Lapping tool on a spindle below the lens, and mounting tool on a second spindle (swung out) uses pitch to hold the lens shown with its concave side down
Concave aspheres fitted in a spectacle frame. The lenses' "minus" powers reduce the test pattern and bring it into better focus at the center of the lenses. Reflections from the non-aspheric anterior surfaces are also visible.
The Canon EF 24-105 f/4L IS USM has three aspheric elements, highlighted in green on the diagram.
Mobile phone camera lens module
The Elgeet Golden Navitar 16mm Aspheric Wide Angle Lens shot and Advertisement from the 1950s.

The asphere's more complex surface profile can reduce or eliminate spherical aberration and also reduce other optical aberrations such as astigmatism, compared to a simple lens.

List of lens designs

This list covers optical lens designs grouped by tasks or overall type.

A biconvex lens

Simple lenses are lenses consisting of a single element.


Company that sells optical design software.

A biconvex lens

It can model the effect of optical elements such as simple lenses, aspheric lenses, gradient-index lenses, mirrors, and diffractive optical elements, and can produce standard analysis diagrams such as spot diagrams and ray-fan plots.