(i) Working: Suppose AB is the point object whose end A is on the axis of telescope. The objective lies (L1) forms image A'B' of object AB at the second principal focus F0 . The image A'B' is real, inverted and diminished. For normal adjustment position this image also lies at first focus (Fe ) of eye lens (L2). This image acts as an object for eye lens and final image is formed at infinity. The final image A''B'' (say), is magnified and inverted.
![diagram of an astronomical telescope](https://www.sarthaks.com/?qa=blob&qa_blobid=4954504561304980095)
![](https://www.sarthaks.com/?qa=blob&qa_blobid=679945310817052120)