3. Microscope Parts.. Parts of the Microscope You should know all the parts of the microscope indicated:

9. Functions of the microscope Arm: The basic frame, used to carry the microscope.

10. Base: The bottom stand, which houses the microscope. Body: contains mirrors to reflect light to the eyepiece.

11. Course Adjustment Knob Roughly focuses the image by bringing the specimen and objective lenses closer together or farther apart

12. Diaphragm. A disc-shaped device, located beneath the stage, used to control the amount of light passing through the specimen.

13. Ocular/Eyepiece The ocular lens, nearest your eye, which magnifies the image already magnified by the objective and brings the light rays to a focus at the eye.

14. Fine Adjustment Knob Clarifies the image of the specimen, by moving the specimen and objective lenses very small distances closer together of farther apart.

15. Light source The beam of the light which passes through the specimen.

16. Nosepiece: The rotating part that supports three objectives with different magnifications

17. Objective Lenses The lenses closest to the specimen, that magnify the image of the specimen.

18. Stage: The flat table-like surface where the slide or specimen is placed. Stage clips: Hold the slide on the stage, to prevent it from slipping around.

19. SLIDE A piece of glass upon which the specimen is placed for viewing.

20. Cover Slip A thin small piece of glass or plastic used to hold the specimen

21. High Power The high power objective on the nosepiece (usually 40 X)

22. Medium power The middle power objective on the nosepiece (usually 10 X)

23. Low power The lowest power objective on the nosepiece (usually 4 X)

24. Magnification—The number of times an objects apparent size is increased by the lens system. The total magnification of the lens system is determined by multiplying the power of the objective times the power of the eyepiece (usually 10x).

25. Resolution The ability of the lens system to distinguish and define fine details in a specimen Resolution allows the viewer to see two objects that are very close together as two objects rather than as one.

26. Field of View The extent of he specimen which is seen through the lens system. The bright circle you see when looking into a microscope. Field of view decreases as magnification increases.

27. Depth of field The ability of a lens system to furnish a distinct image clearly and across the focal plane. Depth of field decreases with the increase of magnification. It’s the range of distance along the optical axis in which the specimen can move without the image appearing to lose sharpness.

29. Parfocal When the objective is in focus, it can be moved from one power to another, with only small fine focus adjustments being necessary. Most microscopes are parfocal.