Concave mirrors and reproduction of an actual object

In summary, concave mirrors create real images of objects by reflecting and converging all rays of light at a single point. This point is also where the reflected light rays appear to be diverging from, giving the impression that the image is located in front of the mirror. Perception of distance is based on relative size and amount of visible detail.
  • #1
boris16
46
0
hiya


I'm having some problems understanding concave mirrors and their reproduction of actual object.



Suppose that a light bulb is placed in front of a concave mirror at a location somewhere behind the center of curvature (C). The light bulb will emit light in a variety of directions, some of which will strike the mirror. Each individual ray of light which strikes the mirror will reflect according to the law of reflection. Upon reflecting, the light will converge at a point. At the point where the light from the object converges, a replica or reproduction of the actual object is created; this replica is known as the image. Once the reflected light rays reach the image location, they begin to diverge . The point where all the reflected light rays converge is known as the image point. Not only is it the point where light rays converge, it is also the point where reflected light rays appear to an observer to be diverging from. Regardless of the observer's location, the observer will see a ray of light passing through the real image location. To view the image, the observer must line her sight up with the image location in order to see the image via the reflected light ray. The diagram below depicts several rays from the object reflecting from the mirror and converging at the image location.

u13l3b2.gif




1)

Can you show me some proof as to why all rays of light from the object converge at the same point ( image point )?




2)


Not only is it the point where light rays converge, it is also the point where reflected light rays appear to an observer to be diverging from.

I'm having hard time understanding how person looking at real image of an object ( created by concave mirror ) will perceive this image?
Will person have the feeling as if real image ( aka reproduction of an actual object ) is located in front of a concave mirror?


*To explain myself further: plane mirrors create virtual images --> images which are formed in locations where light does not actually reach, even though it appears to an observer as though the light were coming from position somewhere behind the mirror. So an image of an object is actually
" created on the surface of a mirror " --> mirror in a way acts as monitor screen.

But with concave mirrors, it sounds to me as if image of an object is created away from the mirror, thus unlike with plane mirrors ( which have image of an object created on its surface, even if it appears to observer as if image is located behind the mirror ), concave mirrors don't have an image of object created on its surface?



3)

BTW-How does one perceive something as being closer or further away? Does it have to do with size of an object ( meaning if object appears bigger than it is closer ) or is there more to it?



thank you
 
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  • #2
1) Yes, this is due to the Law of Reflection which states that a ray of light striking a mirror at a given angle will always be reflected at the same angle. This means that all rays from the object will be reflected and converge at the same point. 2) Yes, a person looking at the real image of an object created by a concave mirror will have the feeling that the image is located in front of the mirror. This is because the reflected light rays appear to be diverging from the image point. When viewed from the right position, the observer will see a ray of light passing through the real image location.3) Perception of something being closer or further away is due to relative size. Objects will appear larger when they are closer and smaller when they are further away, so if an object appears bigger than it is likely to be closer. Additionally, the amount of detail visible on an object can also give clues as to how close or far away it is.
 
  • #3
for your questions. I can provide some explanations to help clarify your understanding of concave mirrors and their reproduction of an actual object.

1) The reason why all rays of light from an object converge at the same point (image point) is due to the reflective properties of the concave mirror. When light rays strike the mirror, they reflect according to the law of reflection, which states that the angle of incidence (incoming ray) is equal to the angle of reflection (outgoing ray). Since the concave mirror has a curved surface, the reflected rays will converge at a point due to the varying angles of reflection. This convergence of rays results in the creation of an image at the image point.

2) When a person looks at the real image of an object created by a concave mirror, they will perceive it as if the object is located in front of the mirror. This is because the reflected light rays appear to be coming from the image point, giving the illusion that the object is located at that point. The person will not feel as if the image is "created on the surface of the mirror" as with plane mirrors, but rather that it is a real object located in front of the mirror.

3) The perception of an object being closer or further away is determined by a combination of factors, including the size of the object and its distance from the observer. In the case of concave mirrors, the size of the object appears larger in the reflected image due to the convergence of light rays. This can give the perception that the object is closer than it actually is. Additionally, the distance between the object and the mirror can also play a role in the perception of distance. Objects closer to the mirror will appear larger in the reflected image, while objects further away will appear smaller. This is due to the varying angles of reflection and the curvature of the mirror's surface.
 

1. How does a concave mirror reproduce an actual object?

A concave mirror reproduces an actual object by reflecting light rays from the object and forming an image at a specific location. The shape of the mirror causes the light rays to converge, creating a magnified or inverted image of the object.

2. What is the difference between a real image and a virtual image produced by a concave mirror?

A real image is formed when the reflected light rays actually converge and intersect, creating a physical image that can be projected onto a screen. A virtual image, on the other hand, is formed when the reflected light rays appear to be converging, but do not actually intersect. This type of image cannot be projected onto a screen.

3. How does the distance of the object from the mirror affect the size of the image?

The distance of the object from the mirror directly affects the size of the image. As the object moves closer to the mirror, the image becomes larger. Conversely, as the object moves farther away from the mirror, the image becomes smaller.

4. Can a concave mirror produce both real and virtual images?

Yes, a concave mirror can produce both real and virtual images. The location of the object in relation to the focal point of the mirror determines whether the image is real or virtual. Objects placed beyond the focal point will produce real images, while objects placed between the focal point and the mirror will produce virtual images.

5. How is the magnification of an image determined by a concave mirror?

The magnification of an image produced by a concave mirror is determined by the ratio of the size of the image to the size of the object. It can be calculated by dividing the height of the image by the height of the object. A magnification greater than 1 indicates a larger image, while a magnification less than 1 indicates a smaller image.

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