[The Microscope]
To make the simple microscope,
the eyepiece and objective were made of two convex (converging) lens.
Use the convex lens imaging principle.
When the object beyond or between the focus and 2focus the image was real inverted.
When the object inside focus;
the effect was same as magnifying glass.
Magnifying glass actually is a convex lens;
its physical principle is the focal length of the magnifying glass is less than its double focal length.
So that the magnifying glass light can't have a real image on the screen,
only be seen with the naked eyes.
It produces a magnification t virtual image.
Light into a plane mirror produce reflection and through the stage the
object along light into objective amplification focal length,
then the light through the eyepiece again amplification focal length,
finally the image to the human eyes.
Fine adjustments are budge plastic bottle cap can slightly change the
focal length observation definition of the objects.
Coarse quasi focal spiral is regulating straight tube height to greatly
focus observation definition of the objects.
