Ray Diagrams

ray diagrams

picture showing where an image will form

principle axis

splits mirror or lens in half

- perpendicular to vertical height of mirror

ray diagrams

picture showing where an image will form

principle axis

splits mirror or lens in half

- perpendicular to vertical height of mirror

center of curvature

center of spherical mirror or lens

- twice the focal point

focal point

half of center of spherical mirror or lens

- half of center of curvature

object (in ray diagram)

always drawn with erect arrow

- must touch principle axis

positive side of mirror

side with object

negative side of mirror

side without object

mirror rules

1. Draw ray parallel to principle axis from top of object to mirror

2. Ray will reflect off through the focal point

3. Draw ray through the focal point from top of object to mirror

4. Ray will reflect off parallel to principle axis

5. Where the two reflected rays intersect is the image

concave mirror: object behind C

real image

small, inverted

concave mirror: object on C

real image

same size, inverted

concave mirror: object in front of C

real image

big, inverted

concave mirror: object on F

no image

concave mirror: object in front of F

virtual image

huge, erect

convex mirror

virtual image

small, erect

positive side of convex lens

side without object (F1)

negative side of convex lens

side with object (F2)

positive side of concave lens

side with object (-F1)

negative side of concave lens

side without object (F2)

lens rules

1. Draw ray parallel to principle axis from top of object to lens

2. Ray will reflect off through the first focal point (F1)

3. Draw ray through the second focal point (F2) from top of object to lens

4. Ray will reflect off parallel to principle axis

5. Where the two reflected rays intersect is the image

concave lens

virtual image

small, erect

convex lens: object behind C

real image

small, inverted

convex lens: object on C

real image

same size, inverted

convex lens: object in front of C

real image

big, inverted

convex lens: object on F

no image

convex lens: object in front of F

virtual image

huge, erect

dual convex lenses rules

1. Ignore Lens 2 for the beginning

2. Draw ray parallel to principle axis from top of object to first lens

3. Ray will reflect off through the first focal point (F1)

4. Draw ray through the second focal point (F2) from top of object to first lens

5. Ray will reflect off parallel to principle axis

6. Where the two reflected rays intersect is the image

7. Draw ray parallel to principle axis from top of object to second lens

8. Ray will reflect off through the first focal point (F1)

9. Draw ray through the second focal point (F2) from top of object to second lens

10. Ray will reflect off parallel to principle axis

11. Where the two reflected rays intersect is the FINAL image