What is the difference between biconvex and convex

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Instant Video Solutions. Request OTP. Question :. Answer :. What is the difference between a double convex lens and a bi-convex lens? What is the difference between a convex lens and concave lens? Explain the difference between a convex lens and a concave lens. As the purpose of this article is to first introduce the basic types of lenses, let us now examine the most common lens configurations. As their name implies, both plano-convex and biconvex lenses have either one or two surfaces with positive spherical contours.

Regardless of design, the thickness at the edge of the lens is always less than the thickness at the center. These lenses are used to focus light to a pre-defined point based on the amount of curvature of their surfaces.

In the case of a plano-convex design, one surface remains flat while the second has a positive curve and for biconvex lenses, both surfaces are positively curved.

In practical use, plano-convex lenses are most commonly employed where the object being imaged is far away from the lens. In optical terms this is called infinite conjugate and an example of this circumstance is focusing light from a distant object such as a star.

Biconvex lenses are also used to focus light but are best employed where the object being imagined is much closer to the lens. This is called finite conjugate and microscopy is a practical example. Plano-concave and biconcave lenses can be thought of as the opposite of plano-convex and biconvex lenses. Having negative curvature means that rather than focusing light, these optical elements disperse the incident energy. By design, the thickness at the edge of the lens is always greater than the thickness at the center.

These optics are often called beam expanders and the below examples demonstrate how light traveling through them is dispersed from its original path. Meniscus lenses have one surface that is concave and one that is convex. Depending on their contour, these optics can be either positive or negative.

If the curvature of the convex side is steeper than the concave side, the resulting light path is refracted towards a predetermined focal point. Conversely, if the concave curvature is greater than the convex side, the light is then dispersed. Negative meniscus lenses can therefore also be thought of as beam expanders. Aspheric lenses differ from all other optics in regards to their shape. As shown above, typical lenses are designed to have spherical contours. Converging or positive lens Curvature on one side of the lens Thicker at its center than at its edges The focal length is defined as positive One focal point Forming a real or a virtual image Biconcave lens is the best option when the object and the image are at an infinite conjugate ratio closer to with a converging input beam.

Diverging lens Curvature on both sides of the lens Thinner at its center than at its edges The focal length is defined as negative Two focal points Forming a virtual image - smaller than the object itself Plano Concave lens is used to expand light or to increase focal lengths or to balance aberrations from other lenses within a system.

Have a changing radius of curvature Focus light to a small point Great for imaging - more focused image Used in cameras Aspheric Vs Spherical Aspheric Spherical Changing radius of curvature in certain areas for better light focusing Higher images quality with fewer spherical aberration Smaller, lighter, flatter Correction of off-axis aberration such as field curvature. Reduction in the number of overall lenses needed to achieve a given result. Fixed radius of curvature Simple design, cheaper to produce Lower images quality when using several spherical lenses.

Which lens type is cheaper to manufacture? Which lens type is converging? What is the difference between Biconvex and Plano-convex lenses? Converging or positive lens Curvature on both sides of the lens Thicker at its center than at its edges The focal length is defined as positive Two focal points Forming a real or a virtual image. Converging or positive lens Curvature on one side of the lens Thicker at its center than at its edges The focal length is defined as positive One focal point Forming a real or a virtual image.

Diverging lens Curvature on both sides of the lens Thinner at its center than at its edges The focal length is defined as negative Two focal points Forming a virtual image - smaller than the object itself. Diverging lens Curvature on one side of the lens Thinner at its center than at its edges The focal length is defined as negative One focal point Forming a virtual image - smaller than the object itself Increase focal lengths Balance aberrations from other lenses within a system.

Converging Curvature on both sides of the lens Thicker at its center than at its edges Positive focal length Two focal points Forming a real or a virtual image Used as magnifying or condensing lenses Used as objectives or magnifiers Used in imaging systems such as telescopes, monocular, microscopes, binoculars, cameras, projectors Human eyes Used in image relays. Diverging Curvature on both sides of the lens Thinner at its center than at its edges Negative focal length Two focal points Forming a virtual image Used to magnify objects - telescope, peepholes, light projection, and binoculars Used in eyeglasses - nearsightedness.

Two focal points Finite conjugate - the object being imagined is much closer to the lens Common use - Microscopy. One focal point Infinite conjugate - the object being imaged is far away from the lens Common use - focusing light from a star Better to deal with spherical aberrations More economic.

Two focal points Used in laser beam expanders, optical character readers, viewers, and projection system. One focal point Used to balance aberrations from other lenses within a system. Have a changing radius of curvature Focus light to a small point Great for imaging - more focused image Used in cameras. Changing radius of curvature in certain areas for better light focusing Higher images quality with fewer spherical aberration Smaller, lighter, flatter Correction of off-axis aberration such as field curvature.

Aberration correction with several spherical lenses reduces the image contrast.