Uses of Convex Lens

Types and Uses of Convex Lens - Plano Convex and Biconvex Lens

A lens that is narrow at the sides and thicker at the center is called a convex lens. A convex lens converges the incoming light rays to a particular point. The convex lens can be broadly classified into two types:

  • 1. Biconvex




  • 2. Plano-Convex



  • Brief History

    Optics features a long history once it involves physics and area exploration. Galileo (1564-1642) was one among the scientists of the early days to use a tiny low telescope using a convex lens to look at the moon and alternative objects within the night sky.

    Mostly telescopes and special optical instruments like spectrometers enabled folks to reveal several secrets of the universe today. All these optical instruments used for magnification essentially has one or more convex lens.

    Uses of the lens

    1) The lens is employed in microscopes and magnifying glasses to converge all the incoming light rays to a specific point
    2) The lens is used as a lens system in cameras as they focus light rays for a clear image
    3) Lens has medical purposes as well, like the correction of hyperopia
    4) It is used in a projector
    5) Plano-convex lens is used in a telescope
    6) It is a primary concentrator for multi-junction star cells

    1)A convex lens is employed in microscopes and magnifying glasses to converge all incoming light rays to a particular point. Magnification is defined as the increase in the size of the appearance of an object or in another word, an enlarged once employing a lens system, the magnification of AN object is given as M= - where M is that the magnification, Di is that the distance of the image and Do is the distance of the object from the lens. 

    In the given diagram, Light rays from the article enter the lens in parallel however they get refracted by the lens and converge as they exit, and build a "virtual image" on the membrane of your eye. This image seems to be larger than the article itself due to basic geometry: Your eyes trace the rays back in straight lines to the reflection, that is farther from your eyes than the article is.



    Magnification of an image

    2) The convex lens is used in cameras. A camera consists of 3 main elements.
  • • The body that is lightweight tight and contains all the mechanical elements.

  • • The lens that could be a convex one (converging lens).

  • • The film or a charged couple device within the case of a photographic camera.


  • The rays of sunshine from the person are converged by the lens system forming a picture on the film or charged couple device within the case of an analog or digital photographic camera respectively.

    The angle at which the rays enter the lens depends on the gap of the item from the lens. If the item is near to the lens the light rays enter at a sharp angle. This ends up in the rays converging far from the lens because the lens will solely bend the sunshine to an exact point that the image has to be focused so as to make on the film. This can be achieved by moving the lens far from the film.

    Similarly, if the item is far from the lens the rays enter at a wider angle. This ends up in the rays being refracted at a trickster angle and also the image forming nearer to the lens. During this case, the lens has to be positioned nearer to the film to induce a sharp focus image.

    Thus the real image of a closer object will be formed further away from the lens than the real image of a distant object and the action of focusing is the movement of the lens to generate the real image to fall on the film or charged coupled device.


                             The working principle of the camera

    3)A convex lens is used for the correction of hyperopia. Farsightedness or hypermetropy is the inability to see distant objects very well, along with having difficulty in focusing on objects that are up close. However, the power to look at close objects needs a unique lens form - a form that the farsighted eye is unable to assume. Later, the farsighted eye is unable to specialize in close objects. The matter most often arises throughout the latter stages in life, as a result of the weakening of the ciliary muscles and/or the reduced flexibility of the lens. These 2 potential causes end up in the result that the lens of the attention will not assume the high curvature that's needed to look at close objects. The lens' power to refract lightweight has diminished and therefore the pictures of close objects area unit centered at a location behind the membrane. On the retinal surface, wherever the light-detecting nerve cells area unit placed, the image isn't centered. These nerve cells so find a hazy image of close objects.
    The cure for the farsighted eye centers around aiding the lens in refracting the light rays. Thus, the farsighted eye is motor-assisted by the utilization of a convex lens. This convex lens can refract the light beam before it enters the attention and later decreases the image distance. By starting the refraction method before lightweight reaching the attention, the image of close objects is once more centered upon the retinal surface.



    The convex lens in treating farsightedness

    4)The converging lens is used in the projector as well. A projector is employed to produce a magnified, real and inverted image of an object just beyond the focal length of a thin convex lens and the image so formed can be projected onto a screen.

    • The image formed here is laterally and vertically inverted. Hence, the transparency has to be in a way that is placed left to right and in an upside down position. Thus, the image we get to see on the screen is a rectified one.
    • The transparency is placed at the focus or the focal point of the lens.

    5)A plano-convex lens is often employed in a telescope wherever each the beam coming back in and also the beam going out square are made parallel. If the lenses are positioned properly this may turn out less deviation than a bi-convex lens. During this case, the correct orientation is to have the curved surfaces of the lens pointing out towards the parallel beams.

    .

    The working principle of the telescope

    6)A convex lens can be used as a primary concentrator for multi-junction star cells. A concentrator optical device was designed for a multi-junction electric cell, CDO-100-C3MJ. For further advancement, a lens was added above the Fresnel lens so as to boost the output power of the setup and cut back the requirement for the employment of solar trackers. The lens setup was tested with the lens setup over a 3-day photoperiod by measurement the voltage, current, irradiance, and temperature at each hour. The results showed that the lens setup created 1.94% additional power, however solely at around noon. The rise in power is because of the lens that focuses on a bigger quantity of irradiance on the electric cell over the course of the day.