The holder is adjustable on all sides, so the
overlay can be moved to different areas of the
microscope image. Remember that when you
move the diapositive, the overlay will move in
the opposite direction. This takes a bit of getting
used to.
You can give the bright lines a coloured back-
ground by putting 32 mm colour filters in the
filter slot (66.7).
Macro device
Like the diapositive overlay device, the macro
overlay (Fig. 67) only works in the 50/50
beamsplitter position (switch rod at middle
position) of the HC FSA 25 PE tube.
The microscope illumination is left switched off
to avoid disturbing image brightening.
The object is placed on the stage under the
mirror housing of the macrodual zoom (67.11) and
illuminated.
Stand lamps, cold-light illuminators and fibre-
optic lamps, etc. are suitable light sources for
macroscopy.
The image is observed in the microscope tube
and focused by turning the knurled ring.
The magnification can be changed continuously
in a range of 1 : 4 by adjusting the knurled ring
(67.7).
When changing the magnification with the zoom
control the object may change position slightly
and go out of focus. It must then be refocused
and moved back into position.
The zoom magnification factors can be read on
the scale (67.8). The magnification also changes
when the distance between the object and the
macro attachment is varied.
Fig. 67 Macro device on HC FSA 25 PE tube
1 Tube flange, 2 Coupling ring, 3 Reflection optics, 4 Coupling
ring, 5 Macro adapter, 6 Screw ring, 7 Zoom setting ring 1 : 4,
8 Scale of zoom factor, 9 Scale of magnification factor of the
working distance, 10 Scale of object distance from the bottom
edge of the mirror housing, 11 Mirror housing
1 2 3 4
5 6 7 8 9 10 11
103