Contrast Methods; Incident Light; Bright Field (Rl); Oblique Illumination (Rl) - Leica DM2700 M Instructions Manual

9. Contrast Methods

9. Contrast Methods

9.1 Incident Light

9.1.1 Bright Field (RL)

• Insert a suitable specimen and rotate an ap-
propriate objective into place. For the basic
bright fi eld settings, start with a 10x or 5x ob-
jective.
• Switch on the light source and toggle to inci-
dent light if necessary (28.5 (toggle switch)).
• Switch on the BF (= brightfi eld) or Smith refl ec-
tor.
• Where applicable, switch the tube beamsplit-
ter* to observation and remove the analyzer*
(56.1), polarizer* (56.2) and IC prism* (57.1)
from the beam path (pull them out part of the
way).
• Adjust the lamp brightness (28.3) and focus the
image.
• Based on the color coding, set the fi eld dia-
phragm position that matches the objective
(Fig. 54).
54

9.1.2 Oblique Illumination (RL)

• First, confi gure the brightfi eld basic setting as
described in Item 9.1.1.
• Activate the Oblique Illumination by rotating
the crank at the rotating wheel (55.3) from the
lowest position (55.2) into the upper position
(55.1).
• Pick the rotating wheel (55.3) in the middle and
rotate it until the desired contrast gets visible.
• To deactivate the Oblique Illumination mode
bring the crank in position (55.2).
Fig. 55 Controls for Oblique Illumination
1 Position "Oblique Illumination mode activated"
2 Position "Oblique Illumination mode deactivated"
3 Rotating wheel for oblique illumination adjustment
3
1
2