Real and virtual image?

Question

When real image is created? Also When Virtual image is created? Explain me.

Answer 1

A real image is when the light rays which seem to diverge from a single point on the image actually do cross; a virtual image is when they seem to be coming from the same place but do not.

When you see a light ray, your brain automatically extrapolates its potition back to where it would have been had it been travelling in a straight line. This is a good adaptation for most purposes, but it allows the brain to be "tricked" by, say, two diverging light rays which have been made to diverge by the interposition of a diverging (concave) lens.

Let's stick with this example. Suppose the two rays started out parallel to one side of the lens. Then after passing the lens, they seem to spread farther and farther apart. If you were to look at them after the lens (eg look at the image the lens produces) then you would see two rays diverging from a point--because of the way your brain extrapolates. This image has no counterpart in real space--there is no such point of divergence. Hence it is called a virtual image. Of necessity, the virtual image point seems to exist somewhere behind the lens.

You can also get virtual images with condensing (convex) lenses, when the object is between the focal point and the lens.

A real image is just the opposite: any two rays which appear to come from the same point actually do cross at that point in space. Of necessity, a real image is formed on the viewing side of the lens.

All of this lens stuff comes from the geometry of similar triangles. It's not too difficult to see if you understand that much geometry. You might search under "lens & ray diagrams".

Answer 2

A real image is an image formed on the opposite side of the lens to the object. It can be projected onto a screen. (eg. in a projector)

A virtual image is an image on the same side of the lens as the object, you see it when you look through the lens. You can't project it onto a screen. (eg. in a telescope).

Answer 3

Images created by both mirrors & lenses

Real image in mirrors:
-----------------------------
a) in concave mirror when:
- 2 rays come from the same point from very far object (infinity > 6 meters)
- object beyond center of curvature
- object at the center of curvature
- object between focus & center of curvature

Virtual image in mirrors:
-------------------------------
a) in concave mirror when:
- object anywhere between the focus & the pole of the mirror
b) in canvex mirror when:
- object anywhere on the principle axis

Real image in lenses:
----------------------------
a) in convex lens when:
- 2 rays from the same point from a very far object (infinity)
- object at a distance bigger than double the focal length
- object at distance equal double the focal length
- object at a distance bigger than the focal length but smaller than double the focal length

Virtual image in lenses:
------------------------------
a) in convex lens when:
- object is anywhere between the lens & the focus
b) in concave lens when:
- object is anywhere on the principle axis

u can see the prove of any case of these cases that i mentioned above by drawing the figure of the lens (or mirror) with the position of the object, focus, etc .... & u will find out how real & virtual images created

i hope u got ur point from my explanation

Answer 4

circulate to a funhouse. seem in any mirror. if your image is upside-down, that's a real image, and no count if it is robust part up that's a digital image. it is via the geometry of how the sunshine rays leap off of concave (real image) or convex (digital image) surfaces. in case you get too on the factor of the concave mirror, your image blows up, distorts, after which you spot a digital (suitable part up) image. you're actually between the mirror and its front concentration. because of fact that a flat mirror has a concentration at "infinity" at the back of you, you're continuously between the mirror and its concentration--subsequently the image in a flat mirror is likewise a digital image. apparently, the plain "concentration" of a convex mirror is at the back of the mirror, yet person-friendly geometry tells you it might would desire to be "at the back of" the concentration of a flat mirror. So in some sense, going "previous infinity" places the factor at the back of the mirror. certainly you do no longer would desire to circulate to a funhouse--you may probable do maximum of this with a cosmetics mirror. you additionally can get real and digital pictures with a magnifying glass. in case you carry the lens at arm's length, and seem at distant gadgets, you will see them upside-down and, curiously, in front of the lens. those are real pictures--the sunshine certainly diverges from the factors it style of feels to. in case you place the lens up on the factor of something, the image would be suitable part up and seem to be at the back of the lens. that's a digital image.