ENGLISH
ENGLISH
Version 3 November-07
Instruction manual 50100XXX Page 21
Optical specifications
Achromatic objectives:
they correct chromatic aberrations so that the optical system can
transmit white light beams without being separated in the spectrum colours.
Specifications of each objective are coded as follows:
40:
Objective magnification
0.65:
Numerical aperture
160:
Tube’s length
0.17:
Thickness of the microscope slide
Achromatic objectives:
Magnifications
4X
10X
20X
40X 60X
100X
Working distance (mm)
17.50
7.32
1.26
0.63
0.41
0.19
Numerical aperture
0.10
0.25
0.40
0.65
0.85
1.25
Total magnification:
This is the result of multiplying the eyepiece's magnifications by the
objective's magnifications.
Objectives
4X
10X
20X
40X (R)
60X (R)
100X(R)(I)
Eyepieces
W.F / 10X Total magnification
40
100
200
400
600
1000
Field of view
4.50 mm 1.80 mm 0.90 mm 0.45 mm 0.30 mm 0.18 mm
P /16X
Total magnification
64
160
320
640
960
1600
Field of view
2.75 mm 1.10 mm 0.55 mm 0.27 mm 0.18 mm 0.11 mm
- W.F.: Wide Field
- P.: plan achromatic.
- R: retractile.
- I: Immersion objective (oil)
N.A.:
Numerical aperture, it determines the objective's properties. The numerical aper-
ture of a microscope objective is a measure of its ability to gather light and resolve fine
sample detail at a fixed object distance. Thus, the bigger it is, the brighter and better resol-
ved the image will be.
Working distance:
It is the distance in millimetres between the microscope slide and the
objective's front lens when the image is focused.
Focal distance:
It is the distance, expressed in millimetres, from the main image plane to
its image focus.
Picture 2
Page 28 Instruction manual 50100XXX Version 3 November-07
Check the sample is properly located on the stage, making sure it is held by the stage
clips. Then, if it does not focus you should revise the pre-focusing control.
If the frontal lens of the objective touches the prepared slide when focusing:
Check the prepared slide is not the other way round (being the cover glass over the
slide) and place it properly in case it is appropriate to do so. Check also the slide's thick-
ness, which has to have a standard thickness of 0,17 mm.
9. RECOMMENDATIONS
As the head is rotary you should rather observe by the stage's frontal part, as it facilita-
tes access to the mechanical control knobs.
When using the oil immersion objective you should notice the following:
In order to use all the numerical aperture of the oil immerson objective:
- Pre-focusing: Focus the sample with the objective with less magnification (4x).
- Put a drop of oil immersion on the cover glass.
- Rotate the nosepiece, place the immersion objective and arrange the focusing with the
fine adjustment knob.
You should avoid air bubbles in the oil so as not to spoil the resulting image. To do so
you should move the pre-focusing control up and down to make the oil layer uniform.
Turn the nosepiece and then locate the oil immersion objective; you can adjust focusing
with the fine knob.
We highly recommend drying the frontal lens after
each use. You should never use a duster. Instead of it you
should use specific optics cloth and liquids that are sold
to this purpose (as the ones for cleaning sunglasses or
binocular lenses). You should not submerge the objective
in any liquid, as this could provoke the lens' detachment.
Depending on the observer preferences the tension of
the coarse adjustment knobs can be modified, since it is
provided with a tension adjustment ring that is located
next to the right coarse knob of the microscope (pic.8).
However, you should avoid loosening it excessively, as
this could produce an involuntary fall of the stage and so
provoke accuracy deterioration.
There is also a control device for the focusing limit. All
models of this series are provided with a ring that avoids
the stage from rising beyond a certain point, which can be
set once the sample has been focussed and thus avoid
possible accidental collisions while observing (pic. 9).
This mechanism also enables the possibility of a quick
focusing, accelerating the observation process when you
are working with different samples.
Picture 8
Picture 9
