Optical Instruments

 
6.5  Optical Instruments
 
Microscope Telescope

Similarities

  • Two convex lenses
  • First image (the object of the eyepiece: reals, inverted
  • Final image: virtual, inverted, magnified

Differences

Lens type: 2 high-powered lens

Lens type: 1 high(eyepiece), 1 low-powered lens

Focal length: \(f_0 < f_e\)

Focal length: \(f_0 > f_e\)

First image: enlarged

First image: diminished

Position of final image: close to the eye

Position of final image: infinity

Distance between the lens: \(D>f_0+f_e\)

Distance between the lens: \(D=f_0+f_e\)

Magnification: \(M=m_0\times m_e\) Magnification: \(M=\dfrac{f_0}{f_e}\)
 

Applications of Small Lenses in Optical Instrument Technology

 
  • small lenses are used in smartphone cameras and CCTV
  • uses small size convex lens
  • produce real, inverted and diminished image at the sensor
  • to produce image with such characteristics (R, I, D) the distance between sensor and centre of lens has to be at least the length of focal length of lens
 
 

 

Optical Instruments

 
6.5  Optical Instruments
 
Microscope Telescope

Similarities

  • Two convex lenses
  • First image (the object of the eyepiece: reals, inverted
  • Final image: virtual, inverted, magnified

Differences

Lens type: 2 high-powered lens

Lens type: 1 high(eyepiece), 1 low-powered lens

Focal length: \(f_0 < f_e\)

Focal length: \(f_0 > f_e\)

First image: enlarged

First image: diminished

Position of final image: close to the eye

Position of final image: infinity

Distance between the lens: \(D>f_0+f_e\)

Distance between the lens: \(D=f_0+f_e\)

Magnification: \(M=m_0\times m_e\) Magnification: \(M=\dfrac{f_0}{f_e}\)
 

Applications of Small Lenses in Optical Instrument Technology

 
  • small lenses are used in smartphone cameras and CCTV
  • uses small size convex lens
  • produce real, inverted and diminished image at the sensor
  • to produce image with such characteristics (R, I, D) the distance between sensor and centre of lens has to be at least the length of focal length of lens