ThermoFisher Scientific DXR xi, User Manual

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Operating the Microscope
Thermo Scientific DXRxi User Guide 25
The information in the next table shows how to configure the illumination controls for
reflected light observations (brightfield and darkfield) when the optional reflected light
BF/DF illuminator is installed.
Table 3. Sample illumination controls with the optional BF/DF illuminator
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Understanding Conjugate Planes and Köhler Illumination , Davidson, M. and Fellers, T.National High Magnetic
Field Laboratory, the Florida State University, 1800 E. Paul Dirac Dr., Tallahassee, FL 32306
Feature Description Available Settings
View Path Directs light through the
microscope eyepiece or to the
video camera (to produce a video
image in the software) or both. • In (eyepiece only)
• Middle (eyepiece and
video image)
• Out (video image only)
Light Path Directs light straight down onto
the sample (BF) or from the edges
(DF) to increase the contrast. • BF (Brightfield)
• DF (Darkfield)
Neutral Density Filter
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The ND filter setting is determined by the Light Path control. When Light Path is set to BF, the ND filter is in
the light path; when Light Path is set to DF, the ND filter is not in the light path.
Reduces glare (protects the viewer
from sudden changes in
illumination, e.g., when switching
the
light path between darkfield
and brightfield).
• In (ND filter in light
path)
• Out (no ND filter)
Field Iris (also referred to
as a “field stop”) Blocks unnecessary light from the
field of view (FOV) to optimize
contrast. • In (iris fully open and
matched to
10x objective)
• Out (iris fully closed)
Aperture Iris (also
referred to as an
“aperture stop”) Reduces reflected illumination
across entire field of view.
Typically used with high
magnification objectives.
• In (iris fully open)
• Out (iris fully closed)
Table 4. Configuring sample illumination with the optional BF/DF Illuminator
Illumination Control
Reflected Light Brightfield
Observation Reflected Light
Darkfield Observation
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Requires an objective that allows darkfield illumination.
View Path Middle position Middle position
Light Path BF DF
ND Filter In (filter engaged) Out (no filter)
Field Iris (FS) Adjust so that iris image
circumscribes objective FOV In (open)
Aperture Iris (AS) In (open) or slightly closed In (open) or slightly closed