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10.9: Summary

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    78405
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    Overview of Mirrors and Lenses

    Table 10.9.1: Summary of properties of mirrors and lenses

    Optical Device focal point description focal length sign image location and type image distance sign orientation magnification
    Concave mirror and converging lens real focal point: in front of the mirror and both sides of the lens

     

     

    f>0

    if o>f: a real image front of the mirror or on the other side of the lens compared to the object

    if o<f: a virtual  images behind the mirror or on the same side of the lens as the object

    if o>f, then i>0

     

    if o<f, then i<0

    if o>f, the image is inverted, M<0

     

     

    if o<f, the image is upright, M>0

    if f<o<2f, the image is magnified, |M|>1

    if o>2f, the image is de-magnified, |M|<1

     

    if o<f, the image is magnified, |M|>1

    Convex mirror and diverging lens virtual focal point: behind the mirror and both sides of the lens

    f<0

    virtual image behind the mirror or on the same side of the lens as the object for all object distances i<0 for all o's the image is upright, M>0 for all o's all images are de-magnified, |M|<1

     

    Ray Tracing

    Concave mirror: object further(closer) than focal point:

    • Principle ray #1: incoming ray parallel to the optical axis will reflect through the focal point.
    • Principle ray #2: incoming ray that goes through (away from) the focal point will reflect parallel to the optical axis.
    • Principle ray #3: incoming rays that goes through (away from) the center of curvature will reflect straight back.

    Conex Mirror:

    • Principle ray #1: incoming ray parallel to the optical axis will reflect away from the focal point.
    • Principle ray #2: incoming ray moving toward the focal point will reflect parallel to the optical axis.
    • Principle ray #3: incoming ray moving toward center of curvature will reflect straight back.

    Converging Lens: object further(closer) than focal point:

    • Principle ray #1: incoming ray parallel to the optical axis will refract through the far focal point.
    • Principle ray #2: incoming ray that goes through (away from) the near focal point will refract parallel to the optical axis.
    • Principle ray #3: incoming ray that goes through the center of curvature will follow a straight path as it goes through the lens.

    Diverging Lens:

    • Principle ray #1: incoming ray parallel to the optical axis will refract away from the near focal point.
    • Principle ray #2: incoming ray that goes toward the far focal point will refract parallel to the optical axis.
    • Principle ray #3: incoming ray that goes through the center of curvature will follow a straight path as it goes through the lens.

    This page titled 10.9: Summary is shared under a not declared license and was authored, remixed, and/or curated by Dina Zhabinskaya.

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