For a microscope, it is important to magnify the image of the electronics properly without losing focus. This can be achieved when a microscope is set parfocal. In this article, a step-by-step strategy is shown on how to properly set up and focus a stereo microscope so that no refocusing is needed when changing the magnification.


1. Keep your back straight Especially, when you are working with a microscope (for a long time) and you lean forward, you tend to slouch, which can cause back pain.
2. Turn the light on on the microscope and place a flat object underneath the microscope The use of a microscope requires good lighting. Enough light is needed to see to observe an object and to see if the image is focused or not.
3. Set the dioptre to 0 Before you can start adjusting any knob, you need to reset the dioptre knobs to 0, because many people do not have the same vision in both eyes.
4. Set the magnification at the lowest magnification possible. Use the magnification knobs.
5. Adjust the focus until the image becomes sharp Use the focusing knobs.
6. Place your eyes 10 mm from the eyepieces (oculars) Do not lean into the eyepiece covers! Leaning into the eyepieces will smudge the lenses, prevents you from seeing a single image, or causes you to see black spots in the image.
7. Adjust the eyepieces until you see a single image The distance between the lenses of the eyepieces should match the (inter)pupillary distance. Try to keep your head stable.
8. Set magnification to the highest magnification possible Use the magnification knobs.
9. Bring the image into focus Use the focusing knobs.
10. Set magnification at the lowest magnification possible Use the magnification knobs.
11. Adjust the dioptre knobs one at a time Close one eye and look through the eyepieces. Make sure to keep your eyes 10 mm from the eyepieces. Adjust the dioptre knob until the image becomes sharp for your single eye. Repeat for the other eye.


In the following video, the step-by-step strategy explained above is demonstrated on the SM-4TP stereo microscope.