Convex lenses are also called converging lenses.
- Object is symbolized by the upward arrow
- Real focus is on the side opposite the object
- Virtual focus is on the same side as object
- 2f is the same as R for a mirror
- f is still the focus as with a mirror
- O is the optical center
- Convex lens creates same images as a concave mirror (sometimes, real, virtual, or nonexistent)
- Example is a magnifying glass
- When object is beyond 2f, image is real, inverted, smaller than object
- When object is at 2f, image is real, inverted, same size as object
- When object is at f, image is nonexistent
- When object is between f and the lens, image is larger, virtual, and upright
Comparison to Concave Mirror
- Concave mirrors (also converging ) yield the same image results as convex lenses.
- The same sign rules hold for the lenses that apply to mirrors.
- Also called “diverging“
- The only image formed is smaller, virtual, and upright
- These cave-in in the middle and are comparable in image formation to convex mirrors
- Use the same sign rules and equations as mirrors!