1. Ray 1. Incident ray parallel to the principal axis
“Ray Tracing – Convex lens” F
Object
Principal axis 1 2 3
Image
Ray 1. Incident ray parallel to the principal axis
- emerges through the focal point
Ray 2. Incident ray through the focal point
- emerges parallel to the principal axis
Ray 3. Incident ray through the pole of the lens
- emerges unaffected
NB: Image is formed at the intersection point of the emerging rays
(Image is inverted, enlarged & real)

2. “Ray Tracing – Convex lens”
Object placed at beyond double the focal length (>2f)
Object F F
Principal axis
Image

3. “Ray Tracing – Convex lens”
Object placed at double the focal length (2f)
Object F F
Principal axis
Image

4. “Ray Tracing – Convex lens”
Object placed between the focal length (f) and double the focal length (2f)
Object F F
Principal axis
Image

5. “Ray Tracing – Convex lens” Object placed at the focal length (f)
Principal axis F

6. “Ray Tracing – Convex lens”
Object placed between the focal length (f) and pole of mirror
Image
Object F
Principal axis F

7. “Ray Tracing – Convex lens”
Summary Table
Object
position
Image description
Type
Orientation
Size
Magnification
>2f
Real
Inverted
Diminished
 1/2 2f
Same 1
Between 2f & f
Enlarged 2 f
No image formed
Between f & pole
Virtual
Upright