Viewing a specimen on a microscope...?

Question

for example, you used a small letter "a" as a specimen.. you focused the microscope and you see already your specimen..

why is the letter "a" inverted when it was focused on the microscope?

Answer 1

Due to the optics involved when you use two lenses to magnify an object, the object will always look upside down and inverted.  Also when you move the slide the image you are looking at is going in the opposite direction you are moving it to.  Move it up to the right it looks  like you are moving it down to the left.

Answer 2

If you see the letter inverted, it may be due to the fact you have took the depth of focus too far down, and you're focusing on an mirror image past the object.