Leica DMi1 Instructions For Use Manual page 41

Eyepiece field number
For a certain microscope configuration, a certain
eyepiece field number (see below), e.g. 20, must
not be exceeded. If the maximum field number is
exceeded, unwanted blurring may occur on the
image field border and/or shading (vignetting) of
the edge of the image.
The eyepiece field number (FOV, field of view)
designates the diameter of the intermediate im-
age in the eyepiece in mm, i.e. the diameter of
the circular diaphragm that limits the image and
is located within the eyepiece.
This FOV is specified on the eyepiece after the
magnification, e.g. 10x/20.
For the Leica DMi1 microscope, the recommend-
ed maximum is FOV 20.
Note:
The maximum permitted eyepiece field number
for a given equipment configuration is calculated
from the following instrument data:
Field performance of objectives
Field performance of intermediate module(s)
Field number of tube
Condenser properties
The lowest occurring value is always decisive.
If, for example, the intermediate modules allow a
field number of only 20, but the objectives and
tube allow 25, only eyepieces up to FOV 20 are
permitted. In this case, eyepieces with FOV 25
can lead to vignetting. Specifically, the following
applies:
The diameter of the viewable specimen area is
calculated by dividing the diameter of the field
of view by the magnification of the objective and
the magnification factor of the stand optics.
Example:
10x/20 eyepiece
PLAN 4/0.10 objective
Magnification factor of the Leica DMi1
1x stand optics
Viewable specimen area
The total magnification of the microscope is cal-
culated by multiplying the eyepiece magnifica-
tion by the magnification of the objective and the
magnification factor of the stand optics.
Example:
10x/20 eyepiece
PLAN 4/0.10 objective
1x magnification factor
Total magnification 10 x 4 x 1 = 40x
Field performance of objectives
see below
The field performance of objectives is not
engraved on the objectives. It can fluctuate some-
what within a class, e. g. the low objective mag-
nifications may well have slightly higher values
than the guiding values listed below:
Objective series Max. recommended
Achromats
HI PLAN achromats
APO L apochromats
N PLAN planachromats
PL FLUOTAR
PL APO planapochromats
11. Technical Description
20 mm
= Ø 5 mm
4x 1
Eyepiece field number
15
semiapo.
®
20 22 25
41