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 principal 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 an astronomical telescope is equal to the sum of the focal length (fo + fe).
- If the distance between both lenses is bigger than (fo + fe), no image can be seen.
Magnification of the astronpmical telescope.