Microscopes

Objective Lens

The lens closest to the specimen that does the primary magnification (e.g., 4x, 10x, 40x).

Eyepiece Lens

The lens you look through, usually magnifying the image by an additional 10x.

Coarse Focus

The large knob used to move the stage rapidly to bring the specimen into rough focus.

Fine Focus

The small knob used for sharp, precise focusing under higher power lenses.

Diaphragm

An adjustable wheel under the stage that controls the amount of light hitting the specimen.

Field of View (FOV)

The visible circle of area seen when looking through a microscope.

Smear Slide

A slide made by spreading a thin layer of liquid sample (like blood) across the glass.

Section Slide

A slide containing an ultra-thin slice of tissue cut using a microtome.

Total Magnification

Calculated as: $\text{Eyepiece Magnification} \times \text{Objective Magnification}$.

Size of Cell Calculation

Calculated as: $\frac{\text{Field of View (FOV)}}{\text{Number of cells that fit across the view}}$.