what is actually about normal adjustment ?

what is the use of it in compound microscope and telescope?

dear chin,

very fundamental question related to microscope and telescope adjustments. as you know, when an object or image at a distance atleast LDDV (least distance of distinct vision), it is clear for healthy human eye. that means, if the source is far from this distance, then our eyes are less strained. you might have felt this when you are seing a far object, you would be comfortable and when you are seing something like a monitor, your eyes would be strained.

Now, applying the same here, when an image you are seing is at infinite, then eyes are not strained. So, adjusting the instrument to form the image as far as possible (mathematically at infinite) is best for viewing for eyes without straining. This adjustment only we call it as Normal adjustment . (see how nice the guys are in naming using the word normal,,,means normal and nothing to strain,,,,it doesnt mean something perpendicular commonly used in mathematics or science)

hope i have done normal adjustment for you.