How total magnification is calculated?
To figure the total magnification of an image that you are viewing through the microscope is really quite simple. To get the total magnification take the power of the objective (4X, 10X, 40x) and multiply by the power of the eyepiece, usually 10X.
Which objective lens provides the highest total magnification?
Lab 1 Microscopy
| Question | Answer |
|---|---|
| This objective lens provides the highest magnification | Oil immersion |
| This objective lens provides the second highest magnification | High-dry |
| This objective lens provides the lowest magnification | Low Power |
| This objectivie lens has the shortest working distance | oil immersion |
Why is immersion oil used for high magnification?
In light microscopy, oil immersion is a technique used to increase the resolving power of a microscope. This is achieved by immersing both the objective lens and the specimen in a transparent oil of high refractive index, thereby increasing the numerical aperture of the objective lens.
What is the highest magnification should you focus before using the oil immersion objective lens?
40X
What kind of oil is used in oil immersion objective?
cedar wood oil
Can you use immersion oil with 40X objective?
Never turn your nosepiece back to the 40x objective when using oil or you will get oil all over that objective. Immersion oil should never be put on any other objective than the 100x!
Should the 100x touch the oil?
The lens should slide directly over the top of the specimen, into the oil, but not touching the specimen or the glass slide. Once the oil immersion (100X) objective lens is in position over the specimen, focus using only the fine adjustment knob.
What will happen to the 40X objective if it touches oil?
Caution: Oil will ruin other objective lenses. Use it only on lenses that are clearly labeled for oil immersion. If you inadvertently get oil on another lens, such as the high dry lens (40x), clean it immediately.
Why is it so important to avoid getting oil on the 40X objective lens?
Never go back to the 10x or 40x objectives after you have applied oil to the specimen since oil can ruin the lower power objectives. [The 4x objective can be used because it is high enough to be above the oil.]
What is the purpose of Koehler illumination?
Koehler Illumination is a process that provides optimum contrast and resolution by focusing and centring the light path and spreading it evenly over the field of view. Sophisticated and well-equipped microscopes fail to yield quality images because of incorrect use of the light source.