Fine Adjustment Knob – This knob is inside the coarse adjustment knob and is used to bring the specimen into sharp focus under low power and is used for all focusing when using high power lenses.

Fine Adjustment knob. part of the microscope that is used for focusing finer details of specimen being viewed. Objectives like low power and high power objectives are used with fine Adjustment knob for clearer image in higher resolution.

The microscope body tube separates the objective and the eyepiece and assures continuous alignment of the optics. It is a standardized length, anthropometrically related to the distance between the height of a bench or tabletop (on which the microscope stands) and the position of the seated observer’s…

Body tube (Head): The body tube connects the eyepiece to the objective lenses. Arm: The arm connects the body tube to the base of the microscope. Coarse adjustment: Brings the specimen into general focus. Fine adjustment: Fine tunes the focus and increases the detail of the specimen.

Answer. Answer: The body tubes in modern microscopes contain a complex assembly of lenses, mirrors, and beamsplitters that transmit light from the objective into the eyepieces.

An objective lens is the most important optical unit that determines the basic performance/function of an optical microscope To provide an optical performance/function optimal for various needs and applications (i.e. the most important performance/function for an optical microscope), a wide variety of objective lenses …

Iris Diaphragm controls the amount of light reaching the specimen. It is located above the condenser and below the stage. Most high quality microscopes include an Abbe condenser with an iris diaphragm. Combined, they control both the focus and quantity of light applied to the specimen.

Diaphragm or Iris: Many microscopes have a rotating disk under the stage. This diaphragm has different sized holes and is used to vary the intensity and size of the cone of light that is projected upward into the slide.

What is an iris diaphragm? From the definition of a diaphragm, an iris diaphragm is a composite type of diaphragm with adjustable or variable opening size. The name is derived from the part of the human eye aptly called the iris, which can dilate and constrict in relation to the size of the pupil.

The role of the diaphragm is to stop the passage of light, except for the light passing through the aperture. Thus it is also called a stop (an aperture stop, if it limits the brightness of light reaching the focal plane, or a field stop or flare stop for other uses of diaphragms in lenses).

The iris controls the amount of light that enters the eye by opening and closing the pupil.

Disadvantages of wet mounts include: Movement: The advantage of observing movement can also be a disadvantage. Due to the movement of the organisms it may be more difficult to take pictures or to make drawings. Focus: Some organisms may swim vertically in the water and therefore move in and out of focus.

Disadvantages: You have to use a kill stain to create contrast; you are unable to see life processes (motility) due to using a kill stain.

Wet Mount. In a wet mount, a drop of water is used to suspend the specimen between the slide and cover slip. This method will help prevent air bubbles from being trapped under the cover slip. Your objective is to have sufficient water to fill the space between cover slip and slide.

Wet mounting requires the image to be mounted on a foam board that is often the same size as the poster, or is centered within the poster board using either a glue stick or spray adhesive. A wet mount is freshly prepared, while a dry mount is pre-prepared and sealed.

For making a wet mount you need these materials:

1. Microscope slides.
2. Cover glasses.
3. The specimen to be observed: make sure that the specimen is sufficiently small and thin.
4. Water: take care that the osmotic potential of the water is compatible with the specimen.
5. Droppers, pipette: these are for transferring the water.

Why are wet mounts used to view biological specimens in the laboratory? to view microscopic organisms that grow in pond water or other liquid media, especially when studying their movement and behavior.

When using a high power microscope, if the sample is not flat, it will not be fully in focus, especially at higher magnifications. Aphid captured at 100x magnification. (Example of a dry mount slide). Wet mount slides are used to view liquids under the microscope.

What organisms can be viewed using a wet mount?

• The organism must be sufficiently thin.
• The organism should have a refractive index which is different from that of the mounting medium (i.e. water).
• The organism should have a color but should not be opaque.