Optika B-350 - Diopter Adjustment Procedure; Condenser Adjustment and Centering; Setting the Numerical Aperture; Phase Rings Centering (Specific Models)

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4.6 Diopter adjustment
Turnthedioptricadjustmentringontherighteyepiecedioptricuptoalignthebottomwiththegradua-
tedring.Turnthecoarsefocusknobinordertofocustheslidewithanobjectivewithlowmagnica-
tion.Adjustthenefocusknobuntilyouobtainaclearanddenedpictureobservingwiththeright
eye,andthenrepeattheoperationwiththeleftdioptriccompensationringandthelefteye.Whenthe
imageappearsinfocus,choosethenecessaryobjectivewiththerevolvingnosepiece.
4.7 Condenser
Raiseorlowerthecondenserthroughtheknob(4)toobtainaclearanduniformilluminationofthe
sample.
Tocenterthecondenser:completelyclosetheirisdiaphragm(3).Usingthecondensercenteringscrews
(2),movethediaphragminthecenteroftheeldofview.Thengraduallyexpandthediaphragmuntil
itistangenttotheedgesoftheeldofview.Ifnecessary,youcanperformanadditionaladjustment.
Thecondenseriscenteredwhentheedgesofirisdiaphragmaretangenttotheeldofview.
4.8 Numerical aperture setting
The value of the numerical aperture (N.A.) of the diaphragm is an indication of the contrast of the illu-
minationsystem.Matchingthevalueofilluminationsystem’sN.A.withthatoftheobjectiveensures
the best results in terms of contrast and image quality. To set the numerical aperture of the Illuminator,
adjusttheopeningoftheirisdiaphragm(3).Inthiswayyoucontrolcontrastandimageresolution.For
sampleswithlowcontrastsettheiristoabout75%ofthevalueoftheobjective’snumericalapertu-
re.
4.9 Phase rings centering (models B-352Ph and B353Ph)
Formodelsequippedwithphasecontrastset,youhavetoperformthecenteringofthephaserings.
Remove an eyepiece from the head and insert the centering telescope in the empty tube.
4.0 USING THE MICROSCOPE