User Guide

490 Series Microscope
AmScope Proprietary Page 12 of 64
2.5 Focusing
2.5.1 Choose an Objective Lens
Turn the nosepiece to choose an objective. It is easiest to use
the lowest magnification first (4X objective) to locate and focus
on the specimen. As you move up in magnification you will
need to refocus the image a little each time.
2.5.2 Parfocal
Under the diopters on the eyepieces, there are numbered
rings. Set these rings to 0 and the image should remain in
focus for the entire magnification range. This will enable you to
stay more in focus when you add a camera or switch objective
lenses.
2.5.3 Focus one eye at time
1. Look with one eye through the right eyetube. Or,
if you have two diopters, select either eyepiece.
2. Close your other eye.
3. Focus the image using the coarse focusing knob.
Adjust the height of the stage until the sample
comes into clear focus.
Note: You can loosen the limit-stop knob (located on the inside of the coarse
focusing knob on the left side of the microscope) in order to give yourself the
full range of motion.
2.5.4 Focus your other eye
1. Close the first eye. Open the other one.
2. Look with the second eye through the
eyepiece.
3. Turn the diopter until the image is clear through
the side as well. Do not turn the focusing knob
when you are adjusting the diopter or you will
have difficulty focusing properly.
2.5.5 Re-center Specimen and Re-focus
When you change magnification levels, you may need to re-center the specimen.
When you change magnification, you will need to re-focus.