5
Nikon Imaging Centre @ King’s College London
Adjusting K
ӧ
hler illumination (Transmitted light)
For transmitted light imaging it is essential to optimise the condenser alignment to ensure that the full numerical
aperture of the microscope system can be realised (to provide an even illumination of the sample). It is therefore
important to ensure that the light passes through the condenser optimally to allow for high quality imaging.
N.B. K
ӧ
hler Illumination adjustment should only be conducted through the eyepiece.
1.
Through the eyepiece, focus on your. Fully close the field iris by turning it anticlockwise. (Fig. 14)
2.
Using the adjustment knob, move the condenser whilst looking through the eyepiece until you see the
octagonal field iris. Turning the knob towards you to bring the condenser lens close to the sample. Adjust the
condenser focus so that the outline of the field iris is sharp and in focus. (Fig. 15)
3.
If required, centre the field iris in the eyepiece using the adjustment screws on the condenser unit.
4.
Once centred, open the field iris again so that the field iris edges are just outside of the field of view.
Nikon
Imaging Centre
King’s College London
Field stop iris
diaphragm
Alignment screws (use
allen key if centering
required)
Condenser
focus
Fig. 13
Condenser
lens
