Microscope part	Explanation
Eyepiece	Eyepiece or ocular. The ones you are using here have 10X magnification. This ocular is 'fixed' and so, initially, you should adjust the focus using the coarse focus knob favouring this eye. One of the eyepieces has a scale inside it, which is useful in estimating the sizes of cells and structures, so you can draw scales on your illustrations.
Eyepiece 2	Eyepiece or ocular. This ocular is adjustable, so, once the specimen is in focus, you can adjust the focus favouring this eye using the knurled ring at the base of this ocular.
Ocular adjust	the knurled ring here enables you to focus each eye independantly of the other. It is good practice to do this and will minimise eye strain.
Interocular	The distance between the eyepieces can be adjusted; this is the interocular distance and can vary from person to person. Make a note of the distance by reading off the scale on the ocular head.
Objective turret	The objective turret holds the objectives. You should have 4X, 10X, 40X and maybe 100X objectives in place. The objectives are par-focal. This means that both low and high power objectives are adjusted to the same object distance. So when you switch from low to high power, only a very small change in focus is necessary. It is good practice to use the knurled ring to swing the next objective into place and not the objectives themselves. The objective lenses form an inverted and magnified image of the object.
Objective 4X	Use the 4X objective to get a low power overview of the shape of a section.
Objective 10X	Set up the microscope with the 10X objective in place.
Objective 40X	Once this objective is in place, only ever adjust the focus using the fine focus control. This is because the distance between the sample on the microscope slide and the end of the 40X objective is really really small and using the coarse focus will smash the slide and/or objective lens.
Objective 100X	This objective has an oil-immersion lens and so is designed to be used with high-grade oil between the lens and the sample.
Stage	This is where the microscope slide is placed. There is a springloaded arm that holds the slide in position.
Stage adjust	This adjuster enables you to move the slide left and right, forwards and backwards, and therefore you can examine your slide thoroughly.
Substage	Condenser and condenser iris diaphragm adjustment. The condenser focuses the light on the slide and affects the cone of light that enters the lens at the tip of the objective. Maximum resolving power is obtained when the cone of light just fills this lens. If the condenser is raised too high and the cone of light does not fill the lens at the tip of the objective then resolution is lost. If it is too low so that some of the light is scattered outside the lens of the objective, glare and impaired resolution will result.
Condenser	The condenser iris diaphragm varies the angle of the cone of light that reaches the specimen and then passes into the objective lens. When the angular aperture is too wide, scattering of light and glare occur. Shutting the iris diaphragm will increase contrast especially if the specimen is lightly stained, but will decrease the ability to see the detail. It should not be used to decrease light intensity.
Coarse focus	This is the coarse focusing control knob. Use this one when the 4X and 10X objectives are in place.
Fine focus	This is the fine focusing control knob. This allows for small adjustments in focus or focal plane.
Intensity	Located on the RHS of the base of the microscope is the light intensity adjustment.
Light source	The light source.
On/off	On/off switch.