Interpupillary distanceadjustment scaleDiopteDummy slideMain switch4A0Specimenholderight intensityknobCondenser centering knobsY-axis knobX-axisknobApertureirisdiaphragmknoFine focusadjustmentknobCoarse focusadjustmentknobField iris diaphragm ringFigure1.1AbinocularcompoundmicroscopeParts of amicroscope:The compound microscope is a delicate instrument composed of many parts that areaccuratelyfilledtogether(Figure1.1)1.Ocularofeyepiecelens.The ocular lens is the lens you look through, it is inserted at the top of thebody tube. If your microscope has one ocular, it is a monocular microscope, ifithastwo,itisbinocular.Itsmagnificationiswrittenonit.2.Body tube.Bodytubeistheoptical housingfortheobjectivelenses3.Objective lenses.The objective lenses are a set of three to four lenses mounted on a rotatingturret at the bottom of thebody tube.The four objective lenses of yourmicroscopeandtheirmagnificationsare:Scanning lens4Xmagnification10XmagnificationLowpowerlens40-45XmagnificationHigh power lensOilimmersionlens100Xmagnification11
11 Figure 1.1 A binocular compound microscope Parts of a microscope: The compound microscope is a delicate instrument composed of many parts that are accurately filled together (Figure 1.1). 1. Ocular of eyepiece lens. The ocular lens is the lens you look through, it is inserted at the top of the body tube. If your microscope has one ocular, it is a monocular microscope, if it has two, it is binocular. Its magnification is written on it. 2. Body tube. Body tube is the optical housing for the objective lenses. 3. Objective lenses. The objective lenses are a set of three to four lenses mounted on a rotating turret at the bottom of the body tube. The four objective lenses of your microscope and their magnifications are: Scanning lens 4X magnification Low power lens 10X magnification High power lens 40-45X magnification Oil immersion lens 100X magnification
The magnification of the objective lens is written on the lens.Note:with the exception of the oil immersion lens all the objective lens is useddry.The magnification of oil immersion lens requires using the lens with specialimmersionoilforproperresolution.4.StageThe horizontal surface on which the slide is placed is called the stage. It maybe equipped with simple clips for holding the slide in place or with amechanical stage, a geared device for precisely moving the slide. Two knobs,either on top ofor underthe stage,move themechanical stage.5.Condenser lens.Condenser lens system, located immediately under the stage, contains asystem of lenses that focuses light on youlspecimen.Thecondensermayberaised or lowered using the condenser knob. An older microscope may have aconcavemirror instead.6.Iris diaphragmIris diaphragm is located below the condenser or immediately below the stagein microscopes without a condenser. It functions in regulating the lightintensity passing through to the stage. More light is required at highermagnification.7. Light sourceThe light source has an (ON/Off) switch & may have adjustable lampintensities&colorfilters.8.BaseBase - also called the supporting stand, rests on the bench.9.BodyArmThe body arm is used when carrying the instrument.10. Nose pieceNosepiece is the mounting for the objective lenses which rotates to bring thedesired objective into position.11. Coarse adjustmentCoarse adjustment knob is a large knob located at either side of themicroscope which functions in controlling the distance between the objectivesand the stage. Use the coarse adjustment only with the scanning (4X) & low-power(10X)objectives.Why?So coarse adjustment is used for rapid focusing of the specimen until thespecimen is roughly in focus & then left alone, in which the fine adjustmentknob controlsprecisefocusing oftheobject.12.Fine adjustmentFine adjustment is a small knob located at either side of the microscope. Thisisusedforthecontrol of the object,precisefocusingyou shoulduse justthefine adjustment knob with the higher magnification objective lenses; Becauseusing thecoarse adjustmentknob with the higher objectivelensesmaydamagethe lens &/or the slide you are observing.Magnification:Compound microscopes consist of two lens system: the objective lens, whichmagnifies,& projects a“virtual image"into the bodytube and the ocular lens,whichmagnifies the image further and projects the enlarged image into the eye.12
12 The magnification of the objective lens is written on the lens. Note: with the exception of the oil immersion lens all the objective lens is used dry. The magnification of oil immersion lens requires using the lens with special immersion oil for proper resolution. 4. Stage The horizontal surface on which the slide is placed is called the stage. It may be equipped with simple clips for holding the slide in place or with a mechanical stage, a geared device for precisely moving the slide. Two knobs, either on top of or under the stage, move the mechanical stage. 5. Condenser lens. Condenser lens system, located immediately under the stage, contains a system of lenses that focuses light on your specimen. The condenser may be raised or lowered using the condenser knob. An older microscope may have a concave mirror instead. 6. Iris diaphragm Iris diaphragm is located below the condenser or immediately below the stage in microscopes without a condenser. It functions in regulating the light intensity passing through to the stage. More light is required at higher magnification. 7. Light source The light source has an (ON/Off) switch & may have adjustable lamp intensities & color filters. 8. Base Base – also called the supporting stand, rests on the bench. 9. Body Arm The body arm is used when carrying the instrument. 10. Nose piece Nosepiece is the mounting for the objective lenses which rotates to bring the desired objective into position. 11. Coarse adjustment Coarse adjustment knob is a large knob located at either side of the microscope which functions in controlling the distance between the objectives and the stage. Use the coarse adjustment only with the scanning (4X) & lowpower (10X) objectives. Why? So coarse adjustment is used for rapid focusing of the specimen until the specimen is roughly in focus & then left alone, in which the fine adjustment knob controls precise focusing of the object. 12. Fine adjustment Fine adjustment is a small knob located at either side of the microscope. This is used for the control of the object, precise focusing you should use just the fine adjustment knob with the higher magnification objective lenses; Because using the coarse adjustment knob with the higher objective lenses may damage the lens &/or the slide you are observing. Magnification: Compound microscopes consist of two lens system: the objective lens, which magnifies, & projects a “virtual image” into the body tube and the ocular lens, which magnifies the image further and projects the enlarged image into the eye