10
STEINDORFF
®
To adjust the aperture diaphragm,
Remove one eyepiece from the tube and look through the tube with your naked eye.
Swing lever to adjust the aperture diaphragm to approximately 2/3~4/5 of the
diameter of the exit pupil of the objective. (See Figure E)
Insert the eyepiece back in the tube.
8.
Engage the objective to be used for observation in the light path, then readjust the focus.
9.
Re-adjust the field iris diaphragm, the aperture iris diaphragm and the brightness and start
observation.
The aperture iris diaphragm determines the numerical aperture of the illumination system. Appropriate
use of the adjustable aperture iris diaphragm (incorporated into the condenser) is most important in
securing correct illumination, contrast, and depth of field. Care must be taken to guarantee that the
condenser aperture is opened to the correct position with respect to objective numerical aperture.
Matching the numerical aperture of the illumination system with that of the objective provides better
image resolution and contrast, and also increases the depth of focus.
Since the contrast of microscope specimens is ordinarily low, setting the condenser aperture iris
diaphragm to between 70% and 80% of the N.A. of the objective in use is usually recommended. In most
applications, this aperture diaphragm setting provides optimum contrast at almost ideal resolution, and is
therefore the best compromise for the human eye.
S-3000 series microscopes are parfocaled, so only minor adjustments using FINE FOCUS knobs are
needed after engaging higher power objectives.
Because of our built-in stop the 4x and 10x can never come into contact with your microscope slides. The
40xR and 100xR may occasionally touch the micro-slide but because these objectives have retractable
resilient mounts your slides will not be damaged
Specimen field size and objective aperture change after every objective change. Therefore, the complete
procedure of focusing, adjustment of field diaphragm, and adjustment of condenser iris diaphragm, at the
same time centering the illumination has to be repeated each time an objective is changed to obtain
optimum results.
