42
4.5 Optical outfits
For metallographic examinations, objectives are
used which have been optimised for incident
light specimens without a coverglass (cover-
glass thickness 0) and incident light techniques.
These objectives can be equally used for trans-
mitted light microscopy provided the transmitted
light specimens are not covered with a cover-
glass.
Objectives with low magnifications and numeri-
cal apertures under 0.25 can also be used for
transmitted light specimens with a coverglass
without loss of image information.
Please note the lettering on the objective:
Objective lettering:
N-PLAN
10 x
0.25
∞
-*
A
HC PL FLUOTAR
50 x
0.80
BD
∞
0 D
Correction
Reproduction
N
umerical
Bright- and dark-
Infinity
Coverglass
ICR-
class
ratio
aperture
f
ield objective
corrected
corrected
prism
type
Eyepiece lettering:
10 x
=
magnification
/20
=
field of view (mm)
M
=
adjustable eyelens
= f
or eyeglass wearers (anti-glare pro-
tection removable or eyecups can be
pushed back)
* - = designed for specimens with or without a coverglass
0 = designed for specimens without a coverglass
Fig. 60
Optical equipment
1
HC PL FLUOTAR BD objective series, M 32 x/0.75 screw thread,
2
HC PLAN 10x/20
and
M eyepieces, HC PLAN
10x/22
and M
eyepieces
Fig. 61
Optical equipment
1
N PLAN objective series for brightfield, M25x/0.75 screw
thread,
2
HC PLAN 10x/20
and
M eyepieces, HC
PLAN 10x/22
and M
eyepieces
2
1
2
1
The DM IRM microscope is based on tube length
∞
(
infinity) and a reference focal length of the
tube lens of f = 200 mm.
