Rules for formation of image by lenses

By following the rules for making a ray diagram, we can draw image formation by lenses.

These rules are applicable for both convex lenses and concave lenses.

    1.   An incident ray coming parallel to the principal axis of a convex lens passes through the focus point (F2) and in the case of a concave lens, it diverges and appears coming from the focus point (F1) at the side of the object.

      

    2.   The incident ray passing through the focus point (F1) becomes parallel to the principal axis of a convex lens.

    

     A ray incident on the concave lens going in the direction of the focus point (F2) becomes parallel to the principal axis after refraction.

    

    3.   The light ray passing through the optical center (O) goes straight without deviation.

     

 Rules for formation of image by lenses video

Related Topics

Image formation by a convex lens when 

1. When an object at infinity

2. Object is at Focus point (F1)

3. When an object beyond 2F1

4. Object between 2F1 and F1

5. Object at 2F1

6. Object between F1 and O

4.  What is a refractive index