Optics-Lenses - image outside the mirror?

[Giuliaa]

Optics-Lenses -- image outside the mirror?

A question in my book asks what are the images formed in this diagram:
http://www.flickr.com/photos/80147355@N05/7362964734/sizes/m/in/photostream/

I thought there was only one, inside the mirror. But it turns out that there is another one, outside the mirror: http://www.flickr.com/photos/80147355@N05/7362964678/sizes/m/in/photostream/

I don't get it. How can a thing inside a mirror create an image in midair??

 

[sankalpmittal]

A question in my book asks what are the images formed in this diagram:
http://www.flickr.com/photos/80147355@N05/7362964734/sizes/m/in/photostream/

I thought there was only one, inside the mirror. But it turns out that there is another one, outside the mirror: http://www.flickr.com/photos/80147355@N05/7362964678/sizes/m/in/photostream/

I don't get it. How can a thing inside a mirror create an image in midair??

You must know that plane mirrors can reflect light (most of) and convex lenses converges the beam to a point (due to refraction). In your diagram , the first image A'B' is formed by refraction of light through convex lens , behind the mirror which is a virtual image . Some of the light energy in the system is also REFLECTED by the plane mirror , shown in diagram by three rays of light which ACTUALLY intersects at a point B'' forming a real image A''B''.

Note that there will be another image i.e. 3rd image (virtual) by first ray and ray AA' but will be so blurred that you'll not be able to see it. Hence its neglected. (Because the resultant energy in the system will be very negligible.)

 

[Drakkith]

This article may help in understanding what a virtual image is: http://en.wikipedia.org/wiki/Virtual_image

The focal point outside the mirror is where the light actual focuses at. Holding a piece of paper or something at that point will let you see the object in view. The image inside or behind the mirror is a virtual image.

 

[sophiecentaur]

A real object will have a virtual image behind a mirror (as we all were taught at School). A real image, projected by a lens, that 'would have been formed' behind a mirror (if the mirror hadn't been there) will be formed as a real image in front of the mirror. This is something that can only be done with a lens as you can't, of course, stick an object behind a mirror and expect a result.

 

[sardar]

The images formed in the diagram are known as virtual images. These are formed when light rays appear to be coming from a point behind the mirror, rather than actually being reflected from that point. In this case, the virtual image is formed outside the mirror due to the curvature of the lens. This phenomenon is known as refraction, where light bends as it passes through a medium with a different density. The lens in this diagram is curved in a way that causes the light rays to converge and form a virtual image outside the mirror. This is a common occurrence in optics and is used in many applications, such as in cameras and telescopes. It may seem counterintuitive, but with the right conditions, a virtual image can be formed outside of a mirror or lens.