Optical Instruments

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