Lenses. Lenses are transparent objects that are used to refract light to help form an image There are two types of lenses:. Converging lens (aka Convex Lens). DO NOT COPY. Diverging lens (aka Concave Lens). Go experiment with shooting more than one
DO NOT COPY
Diverging lens (aka Concave Lens)
Go experiment with shooting more than one
light ray through the different lenses in your
ray box kits
what does a converging lens do to light?
What does a diverging lens do to light?
What happens when you shine light through one lens, and then the other?
Which lens is like the one in your eye? Glasses?
Find the F and mark. What happens when you shoot a ray through the F? Shoot a ray parallel to PA? Shoot a ray through O?
PA = principle axis
F = focal point
O = optical center
F’ = secondary focus
2F’ or 2F = focus length from mirror x 2
Case 1: An object outside 2F’
Case 2: An object between 2F’ and F’
Case 3: An object on F’
Case 4: An object between F’ and Mirror
Try Worksheet – Converging lenses ONLY
1. Magnifying Glass
- image is enlarged
- object must be between focal length and lens
- the mirror goes up and stops reflecting image to the viewfinder.
- The shutter opens and the film or sensor is exposed to form inverted image
BEFORE THE SHOT
AFTER THE SHOT
When the person is ready to take the photo, the mirror goes up and stops reflecting image to the viewfinder.
The shutter opens and the film or sensor is exposed – information is collected to create the negative or digital image.
- lens focus and inverts image to back of eye (retina)
- Your brain is what really flips the image.
- far sighted = can’t see near because eye converges beyond retina.
- Converging lens refocuses light onto retina
5. Movie Projector
- film has images inverted so they appear upright on screen