Note that they are upside down, and very small. Now, with your back facing the class, hold the mirror up near your face and slightly to one side. The students can now see a very large imaged of your face which is upright.
Turn from side to side so the whole class can see you. This happens because a concave mirror will simply create an inverted real image when the object is beyond the focal point. Plane mirrors, convex mirrors, and diverging lenses will always produce an upright image.
A concave mirror and a converging lens will only produce an upright image if the object is located in front of the focal point. If the reflecting surface is convex, then it is a convex mirror. The inner surface of a spoon acts like a concave mirror, while its outer surface acts like a convex mirror. We know that the image of an object formed by a plane mirror cannot be obtained on a screen. For a concave mirror, the image formed when the object is at this position is virtual and erect.
As the face is moved away, the size of the image diminishes and gets inverted at the focal point with a real nature at infinity. The image thus gets real and inverted when the object is moving away from the spoon.
When you look at the backside of the spoon your upright reflection will be seen. When you look at the inner side of the spoon your image will be upside down. Beginners to optics find the idea of virtual images confusing. A real image can be seen on a screen i. With a virtual image the light rays never come to a focus so there is no place you can put a piece of paper to see the image. However your eye contains a lens and can bring the diverging light rays to a focus on your retina.
Hence your eye can see a virtual image even though it couldn't be projected onto the sheet of paper. You might notice when looking at yourself in a concave mirror that your image flips not at the focal point,f, but at the radius of curvature of the mirror, R.
Applying the lens equation one determines that the image of an object your face for example should flip at the focal point. So what gives? The answer is that the mirror and the lens in your eye act together kind of like a compound telescope.
The lens in your eye focuses this virtual object onto the back of your eye and the image is not inverted usually the convex lens in your eye inverts a real image. Because your eye is used to seeing real image - the image of your face appears upright. Sign up to join this community. The best answers are voted up and rise to the top. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Learn more.
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