Microscopes

What happens to depth of focus when increasing magnification

Decreases as magnification increases

What happens to detail when increasing magnification

Detail increases with increasing magnification

What is Field of View?

Field of view is the illuminated area that you can see when you look into the microscope. As magnification increases, the diameter of the field of view decreases. In other words, you can see less area of the specimen as you increase the magnification.

When increasing magnification what happens to the field of view

Gets smaller in diameter with increasing magnification

Leeuwenhoek

Made the first compound scope by assembling a series of magnifying lenses Used the scope to study pond water and called the living protists "animalcules"

What is resolving power, or resolution?

The ability of a microscope to focus an object with the most clarity

What appears to happen to the magnified object when you move your focused slide in any one direction?

The image moves in the opposite direction

What is depth of focus?

This refers to thickness of the plane of focus. If your specimen is a thick specimen, you may have to use the fine adjustment knob to find the exact area in that specimen in which you have the best image. (Thinner specimens are easier)

Why do we use the coarse adjustment only in low power?

Using the coarse adjustment moves the stage significantly. If we use this adjustment know in medium or high power, the objective lens can be forced onto the slide and crack the slide or ,even worse, crack the objective lens

What are the steps of calculating a specimen's size using microscopy?

a. focus the object in the highest magnification in which you can see most of the image b. use the chart to figure out the diameter of the field of view for that magnification c. estimate the number of specimens that could possible fit across the field of view d. divide the diameter of field of view by the number of specimens e. Tah Dah

Steps of focusing a microscope

a. make sure microscope is on low power and turned on b. place slide on stage and under clips c. while looking in eyepiece use coarse adjustment knob to bring image into focus as clearly as possible d. center the object and re-focus e. use fine adjustment to further focus f. move to medium power and refocus the specimen using fine adjustment only g. if applicable move to high power and use fine adjustment to focus again.

Robert Hooke

• Used microscopy to study insects and plant structures • While viewing cork he came up with the word "cell"