The depth of field depends inversely on the numerical aperture of the lens, i.e. for a strong lens the depth of field is quite small.

Depth offield vsdepth of focus microscope

By the depth of field of the microscope we mean the thickness of the layer of the preparation in which the sharply displayed objects are located. The depth or thickness of such a layer of the object indicates the depth of field, or depth of field (penetration ability i.e. "ability to draw sharply in depth") of the lens. Objects that lie above and below this layer are seen out of focus or are not visible at all.

Lenses with lower magnification (eg 4x, 10x) have a greater depth of field than lenses with higher magnification (eg 40x, 60x, 100x). Depth of field can be increased by zooming in or lowering the position of the condenser. Thus, details and impurities lying above and below the object can be displayed. On the contrary, we achieve a decrease in the depth of field as the aperture of the lens increases.

Depth of focusdefinition

This experiment explores the polarization, spatial and temporal coherence of the output of a He-Ne laser, as well as the basic conditions for laser action. Charles Townes (Nobel Prize 1964) and Arthur L. Schawlow (UofT BSc 1941, UofT PhD 1949, Nobel Prize 1980) invented the laser in 1958.

When viewing the transparent preparation, we make a cut through the preparation, we can clearly observe only a thin layer. We are talking about„the optical section“. The microscope will clearly show us the structures that lie in it. So focusing is actually just the localization of object structures, or the entire observed object into this layer. By turning the micrometric screw, which allows us to focus on the given object, we pass a series of consecutive optical sections through the observed object.

3rd year Arts and Sciences undergraduate and Varsity Blues volleyball player, Anastasia Danilova, working on an earlier version of the Helium-Neon Laser.