Effects Of The Field Diaphragm; Centering The Aperture Diaphragm (As); Use Of Color Filters - Optika Italy B-1000 Serie Manual De Instrucciones

12.7 Effects of the field diaphragm
Field diaphragm adjusts the illuminated area to obtain a high
contrast image.
Set the diaphragm according to the objective in use until it
circumscribes the field of view, in order to eliminate unnecessary
light to eyepieces.
12.8 Centering the aperture diaphragm (AS)
1. Move the selector on the reflected light illuminator in the
position "BF". (Fig. 39)
2. Completely pull out the aperture diaphragm selector ⑤ to
fully close the diaphragm. (Fig. 45)
3. Remove one eyepiece.
4. While looking into the empty eyepiece sleeve, use the
provided Allen wrench into the centering screws ⑥ to bring
the bright spot in the centre of the field of view. (Fig. 45)
5. 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 move the diaphragm lever to
about 70%-80% of the objective's N.A. If necessary, remove
on eyepiece and, looking into empty sleeve, adjust the lever
in order to obtain an image like the one in Fig. 34.
12.9 Use of color filters
1. Insert the desired filter for the observation in the slot placed
in the illuminator's side. (Fig. 46)
2. First click stop position leaves filter not inserted, while second
click stop position inserts filter into the light path.
FILTER
Blue Converts the source colour temperature to daylight
Increase the contrast in black and white
Green
Contrast filter for the observation of wafers and
Yellow
Frosted white Reduces lighting irregularities by creating a
APPLICATION
photography
semiconductors
homogeneous field of view
Page 30
F ig. 44 F ig. 44
⑤
⑥
F ig. 45 F ig. 45
F ig. 46 F ig. 46