There are certain rules that we use to get images in a beam graphic, you start by drawing the main axis. This is the horizontal line from which you create your chart. Next, draw the lens symbol – in the middle of this line perpendicular to it – and mark in F, P and 2F (these must be drawn to scale!). These two incident rays pass through the pixel to the top of the object. In fact, all the rays of light emanating from the top of the object pass through the pixel. It is therefore enough to build a ray graph to determine the position of the image; Use both thinking rules. Then draw the reflected rays for the two incident rays given through the same pixel. So far, we have seen via radiation diagrams that a real image is produced when an object is more than a focal length from a concave mirror; and a virtual image is created when an object is within a focal length of a concave mirror (i.e. before F). But what happens if the object is at F? That is, what kind of image is created when the object is exactly at a focal length from a concave mirror? Of course, a ray chart is always a tool to find the answer to such a question. However, when a ray chart is used for this case, an immediate difficulty arises. The incident beam that starts from the top of the object and passes through the focal point does not hit the mirror.

Therefore, another incident beam must be used to determine the intersection of all reflected rays. Any incident beam of light would work as long as it hit the mirror. Remember that the only reason we used both we have is that they can be drawn conveniently and easily. The diagram below shows two incident rays and the corresponding reflected rays. The theme of this unit was that we see an object because light moves from the object to our eyes when we look at the object along a line. Similarly, we see an image of an object because the light of the object is reflected by a mirror and moves towards our eyes when we see at the position of the image of the object. Based on these two basic premises, we have defined the location of the image as the place in space from which the light seems to diverge. Ray diagrams were a valuable tool for determining the path of light from the object to the mirror to our eyes.

In this section of Lesson 3, we examine the method of drawing ray diagrams for objects placed in various places in front of a concave mirror. To draw these diagrams, we must remember the two rules of reflection for concave mirrors: 2. Once these incident rays hit the mirror, reflect them according to the two rules of reflection for concave mirrors. In this diagram, five incident rays are drawn together with the corresponding reflected rays. Each beam intersects at the point of the image, then diverges towards the eye of a viewer. Each observer would observe the same image location and each beam of light would follow the law of reflection. However, only two of these rays would be needed to determine the position of the image, as only two rays are needed to find the intersection. Of the five incident rays drawn, two correspond to the incident rays described by our two reflection rules for concave mirrors. Since this is the easiest and most predictable pair of rays, these will be the two rays used for the rest of this lesson. It should be noted that the process of creating a ray chart is the same no matter where the object is located. Although the result of the ray diagram (image position, size, orientation and type) is different, the same two rays are always drawn. Both reflection rules are applied to determine the location from which all the reflected rays deviate (which for real images is also where the reflected rays intersect).

Once the method of drawing beam diagrams is practiced several times, it becomes as natural as breathing. Each chart provides specific information about the image. The following two diagrams show how to determine the position, size, orientation, and type of the image for situations where the object is at the center of the curvature and when the object is between the center of curvature and the focal point. Some students have difficulty understanding how to derive the entire image from an object once only one point in the image has been determined. If the object is a vertically aligned object (for example, the arrow object used in the following example), the process is simple. The image is only a vertical line. Theoretically, it would be necessary to select each point of the object and draw a separate ray diagram to determine the position of the image of that point. This would require a lot of Ray diagrams, as shown below.

The method of drawing ray diagrams for concave mirrors is described below. The method is applied to the task of drawing a ray diagram for an object beyond the center of curvature (C) of a concave mirror. However, the same method works to draw a beam diagram for any object position. then he goes back and makes a reflection angle r Draw the three rays as described above – the point at which they intersect is the actual image. If they diverge, trace them back to the virtual pixel with a dotted line. The animations show you how to do this. Rule 2: Incident light rays directed at the optical center flow directly – in other words, they are not refracted. We see that the beam passing through the center of the curvature returns to the same path. We see that the beam that passes through the optical center is created without deviation Fortunately, there is a shortcut.

If the object is a vertical line, the image is also a vertical line. For our purposes, we will only deal with simpler situations where the object is a vertical line, the underside of which is on the main axis. For such simplified situations, the image is a vertical line, with the lower end on the main axis. It is seen that the beam passes through the focus after reflection Convex lens: object at 2F, object between F and 2F, object at F, object between P and F and object beyond 2F The focal length of a lens is the distance between the pole of the lens and the main focus. If the lens has real focus, the focal length is positive. If he has a virtual goal, it`s negative. A radius diagram for the case the object is in front of the focal point is shown in the diagram on the right. Note that in this case, the light rays diverge after being reflected by the mirror. When the light rays diverge after reflection, a virtual image is created. As with flat mirrors, the position of the image can be found by following all the rays reflected backwards until they intersect.

For every observer, the reflected rays seem to deviate from this point. Thus, the intersection of the extended reflected rays is the pixel. Since light does not really penetrate this point (light never moves behind the mirror), the image is called a virtual image. Note that if the object is in front of the focal point, its image is a vertical, enlarged image that is on the other side of the mirror. In fact, one generalization that can be made about all virtual images created by mirrors (flat and curved) is that they are always straight and always on the other side of the mirror. The main focus of a convex lens (sometimes called the focal point) is the point on the main axis through which rays of light moving near and parallel to the main axis pass through the lens after refraction. Rule 3: Incident light rays directed at the opposite focal point become parallel to the main axis after passing through the lens. (This is the opposite concept of Rule 1.) Earlier in this lesson, the following diagram was shown to illustrate the path of light from an object to the one-eye mirror. We see that the beam seems to pass through the focus on the left Rule 1: The incident light rays parallel to the main axis seem to come from the opposite focal point after being refracted through the lens. In the three cases described above – the case where the object is beyond C, the case where the object is in C and the case where the object is between C and F – the light rays converge towards a point after being reflected by the mirror. In such cases, an actual image is created.

As already mentioned, a real image is formed when the reflected light flows through the location of the image. While flat mirrors still produce virtual images, concave mirrors are capable of producing both real and virtual images. As noted above, actual images are created when the object is at a distance of more than one focal length from the mirror. A virtual image is created when the object is within a focal length of the concave mirror. To see why this is so, a ray chart can be used. We see that the beam passing through the focus on the left side becomes parallel to the main axis after refraction. In the case of the object located at the focal point (F), the light rays do not converge or diverge after being reflected by the mirror. As the diagram above shows, the reflected rays move parallel to each other.

Subsequently, the light rays do not converge on the side of the mirror object to form a real image; They also can`t be extended backwards on the opposite side of the mirror to cut into a virtual image. So how do you interpret the results of the radiation diagram? The answer: There is no image!! Surprisingly, when the object is at the focal point, there is no place in space where an observer can see from where all the reflected rays seem to diverge. An image is not created when the object is in the center of a concave mirror. 1. Select a point on top of the object and draw two incident rays moving towards the mirror.