Aperture Diaphragm (As); Use Of Tint Plates - Optika Italy B-1000 Serie Manual De Instrucciones

12.4.2 Aperture diaphragm (AS)
1. Rotate the knurled ring of the aperture diaphragm
④ in the direction shown by the arrow to fully
close the diaphragm.
2. Remove one eyepiece.
3. While observing in the empty eyepiece holder, use
the provided Allen wrench and use the centering
screws ⑤ to bring the bright spot in the centre of
the field of view. (Fig. 51)
4. The illuminator is centred when the diaphragm
image is symmetrical to the field of view.
• The Numerical Aperture (N.A.) value of the
aperture diaphragm affects the image contrast.
Increasing or reducing this value one can vary
resolution, contrast and depth of focus of the
image.
• With low contrast specimens rotate the ring
on the illuminator to set the numerical aperture
value to about 70%-80% of the objective's N.A. If
necessary, remove on eyepiece and, looking into
empty sleeve, adjust the ring of the illuminator in
order to obtain an image like the one in Fig. 28.
12.5

Use of tint plates

Three tint plates are supplied with the microscope:
• Lambda (l) plate (1
• Lambda/4 (l/4) plate
• "Quartz wedge" (Q) plate
1. Insert in the right slot of the Bertrand lens ① one
of the tint plates ②. (Fig. 52)
2. In polarized light, inserting one of the plates will
have chromatic effects on the specimen.
• Using the l plate (also called 1
specimen will take a magenta tinge.
• Using the l/4 plate the specimen will take a colour
tending to pale yellow.
• Using the Q plate the specimen will show a series
of coloured bands that will fade as the plate is
inserted.
order Red)
st
order Red) the
st
①
②
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⑤
④
F ig. 51 F ig. 51
F ig. 52 F ig. 52