Oh, and Math

Thicker in the middle than the edges.

Rays converge to focus an image.

has + focal length

1. A ray parallel to the principal axis will refract through the focal point.2. A ray through the focal point will refract parallel to the principal axis.3. A ray through the center of the lens maintains its course.

Lens is thinner in the middle than the edges.

Refracted rays diverge on other side of lens.

has – focal length

Back trace the refracted ray

Back trace the refracted ray

Back trace the refracted ray

virtualsmallerupright

Convex Lens: Real image unless object isin front of F, then virtual image is formed.Inverted unless in front of F, then uprightimage is formed. Farther away object is smaller image is. Bring in closer then image is enlarged. Andwhen object is in front of F, huge and same side as F.

Concave Lens: Image is Virtual, smallerand Upright. Also, on same side of lens as object.

Same Formula: 1 + 1 = 1do di f

m = hi = -di

ho do

1. A 18-cm tall object is placed 33 cm from a converginglens that has a focal length of 10 cm. How far from the lens will the image be formed? How tall is the image formed?Describe the image formed.

2. The same 18-cm tall object is now placed 33 cm from a diverging lens that has a focal length of -28 cm. How far from the lens will the image be formed?How Tall is the image?Describe the image.