- 49 Views
- Uploaded on
- Presentation posted in: General

Spherical refracting surfaces - Six cases

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Spherical refracting surfaces - Six cases

- Sign Convention to be used in the optics equations:
- The object distance p is positive for a real object. It would be negative for a virtual object, but that is a rare situation.
- The image distance i is positive for a real image and negative for a virtual image.
- Radii of curvature get their sign based on whether the centers of curvature are on the “R-side” or “V-side”.

From posted “Practical Rules” on Lecture Materials page:

V-side

So

r < 0

R-side,

So

i > 0

V-side

R-side

So

r > 0

i > 0

Note: p > 0 since the object is real.

V-side

So

r < 0

i < 0

V-side

So

i < 0

R-side

R-side

So

r > 0

V-side

So

i < 0

R-side

So

r > 0

V-side

So

r < 0

i < 0

R-side

Converging Lens (f > 0)

Focal point

Diverging Lens (f < 0)

Converging Lens

f > 0

Focal point

f < 0

Diverging Lens

Converging Lens

f > 0

Focal point

f < 0

Diverging Lens

R-side

V-side

V-side

R-side

R-side

V-side

Locating the Image

(From posted “Practical Rules” on Lecture Materials page)

Magnifying glass

Typical “near point”

Angular magnification

Simple thin-lens microscope

Not to scale.

s = “tube length”

The eyepiece acts as a magnifying glass for the image from the objective lens. The final magnification M is the product of the lateral magnification m of the objective lens and the angular magnification m of the eyepiece.

Angular magnification

Refracting telescope

ey

Not to scale.

A distant object subtends an angle ob. The virtual image viewed through the telescope subtends ey.

Eyeglasses

myopic eye (shortsighted)

corrected with diverging lens

hyperopic eye (farsighted)

corrected with converging lens