How to calculate the enlargement at low power

What happens when you go from low power to high power on a microscope?

When you switch from low power to high power on a microscope, the high-performance objective lens moves directly over the specimen, and the objective lens moves with it less Magnification rotates away from the sample. This change changes the magnification of a sample, the light intensity, the area of ​​the field of view, the depth of field, the working distance and the resolution. The image should stay sharp if the lenses are of high quality.

Change in magnification

Switching from low to high power increases the magnification of a sample. The amount that an image is enlarged is equal to the magnification of the eyepiece lens or the eyepiece multiplied by the magnification of the objective lens. Usually the eyepiece lens has a magnification of 10x. A typical standard laboratory-grade optical microscope typically has four objective lenses ranging from a low power of 4x to a high power of 100x. With an eyepiece strength of 10x, the standard optical microscope offers a magnification of 40x to 1000x.

Light intensity decreases

The light intensity decreases with increasing magnification. There is a certain amount of light per area, and as you increase the magnification of an area you are looking at a smaller area. So you see less light and the picture appears darker. The image brightness is inversely proportional to the quadratic magnification. At four times the magnification, the picture is dimmed 16 times.

Field of view

If you work on the microscope at high power, the field of view is reduced. The field of view is inversely proportional to the magnification of the objective lens. For example, if the diameter of your field of view is 1.78 mm under 10x magnification, a 40x lens will be a quarter as wide, or about 0.45 mm. The sample appears larger at a higher magnification because a smaller area of ​​the object is spread out to cover the field of view of your eye.

depth of field

The depth of field is a measure of the thickness of a focal plane. If as the magnification increases, the depth of field decreases. For example, at low magnification you can see the entire volume of a slipper parameter, but if you increase the magnification you may only see one surface of the protozoa.

Working distance

The working distance is the distance between the sample and the objective lens. The working distance decreases with increasing magnification. The high power objective lens must be much closer to the sample than the low power objective lens to be in focus. Working distance is inversely proportional to the magnification.

Oil immersion

Microscopes enlarge the appearance of an object by bending light. Higher magnification means that the light is bent more. At a certain point the light is bent so much that it cannot pass through the objective lens. At this point - usually about 100 times on standard laboratory microscopes - you need to put a drop of oil between your sample and the objective lens. The oil "loosens" the light in order to stretch the working distance and makes it possible to photograph at high magnifications.
Main Electronics What happens when you go from low power to high power on a microscope?

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