105
The total magnification can be roughly worked
out using the scale divisions on the macrodual
zoom:
The following factors are multiplied:
– magnification factor of the working distance
(scale 67.9, e.g. – 0.11x)
– zoom factor (scale 67.8, e.g. 1x)
– correction factor of the reflection optics
(without engraving 1.17x)
– eyepiece magnification (e.g. 10x)
e.g. 0.11 x 1 x 1.17 x 10 = 1.29
The total magnification in the eyepiece would
therefore be 1.29x.
Using the macrodual zoom as a drawing device
Drawing microstructures under the microscope
has the advantages over photomicrography that
significant details can be high-lighted and that
structures can be depicted in three dimensions.
Apart from this, drawing with the superimposed
image method is a valuable didactic exercise.
It is done by superimposing the drawing area
(the area of the stage under the mirror housing
of the macrodual zoom) onto the microscope
image. The drawing area or sheet of paper is
homogeneously illuminated with a stand lamp or
table lamp.
The microscope illumination and illumination of
the drawing area are matched providing the
lamps are adjustable; otherwise the brightness
of the drawing area can be varied by altering the
proximity of the lamp.
The exact magnification of the object in the
drawing is most easily determined by means of
a stage micrometer, by transferring the length
measured by the stage micrometer onto the
drawing. The magnification can also be
calculated as follows:
M
Ze
=
M
Obj
5x
M
Ze
= ––––––––––––– e.g. ––––––––––––– = M
Ze
9.6x
M
Ze
=
F
Zoom
x F
D
x F
E
4 x 0.11 x 1.176
M
Ze
= magnification in the drawing plane
M
Obj
= objective magnification
F
Zoom
= magnification factor of the zoom optics,
scale 67.8.
F
D
= magnification factor of the object
distance, scale 67.10
F
E
= correction factor of the reflection optics
(1.176x)
The magnification can be altered by changing
the zoom setting (scale 67.8) or the level of the
drawing plane.
