3 First Steps |
3.7 Adjusting the Resolution and Depth of Field
Primotech | Document 430055-9044-008 V.1.0; 03 / 2014
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3.6.4 Adjusting the Transmitted Illumination Size
The
luminous field diaphragm
specifies how much of the object is illuminated
without altering the brightness itself. Opening the diaphragm causes more of the
sample to be illuminated.
Procedure
1
To adjust the luminous field diaphragm, turn the corresponding ring.
2
Adjust the diaphragm such that it just disappears from the field of view when
looking through the eyepieces.
3.7 Adjusting the Resolution and Depth of Field
The aperture diaphragm controls the size and shape of the cone of light from the
condenser. This in turn affects the resolution, depth of field, and contrast of the
image.
Resolution refers to the size of object that can be observed: a higher resolution
means smaller objects can be observed. Depth of field refers to the range of
distances over which an object appears in focus: a large depth of field means that
objects at different distances from the eyepiece are in focus. A short depth of field
means that only objects at a specific distance are in focus.
The resolution is inversely proportional to the depth of field and contrast:
¢
Opening the diaphragm increases the resolution but decreases the depth of
field and contrast.
¢
Closing the diaphragm decreases the resolution but increases the depth of field
and contrast.
