Achieving the correct eye point level
Once the fields of view are centred you adjust the height of the camera above the
eyepiece to achieve optimal field flatness (evenness of illumination) with a sharp boundary
to the circular field of view. Some eyepieces give a softer boundary than others and some
microscope illumination systems can never give a completely flat illumination but the point
is you want to find the height that minimises any vignetting (figure 5.7).
Figure 5.7 Adjusting the height of the camera above the eyepiece such as to provide the flattest illumination
across the field. a) The camera is too high above the eyepiece. b) The camera is too close to the eyepiece.
c) The camera is just at the optimal level. Note that while you make this adjustment you may need to also
adjust the axis as well (as shown if figure 5.6) because while making these height adjustments you may
throw the camera slightly off axis.
The pictures in figures 5.6 and 5.7 were taken using a PUMA microscope with Abbe
condenser and Kohler illuminator using a x20 Olympus SPlan objective.
OptArc AF51 Camera Page 59 of 99 User Guide v1.02
