Optical Instruments - Astronomical Telescope

Astronomical Telescope

	Astronomical Telescope
Objective lens	Lower power
Eye lens	Higher power
Position of the object	At infinity
Nature of the image, I1	Real, inverted and magnified
Position of the image, I1.	At the principle focus of object lens, fo.
Nature of the image, I2	Virtual, inverted and smaller in size.
Distance in between the two lens	The distance between the object lens and the eye lens in a compound microscope is equal to the sum of the  focal length (fo + fe). If the distance between both lenses are bigger than (fo + fe), no image can be seen.
Magnification of the compound  microscope.	$$m=\frac{\text{Focal length of the object lens, }{f}_o}{\text{Focal length of the eye lens, }{f}_m}$$