In light microscopy, lower magnification objective lenses are further from the specimen and survey a larger area, meaning more light enters the microscope, explains How Stuff Works. More magnification means the lens is closer to the stage, which also means less light enters the microscope, making the field of view dimmer.Know More
A light microscope works by shining a light up through objects, such as cells, on a slide. The light passes through the objects up into a small, spherical objective lens, up through the body of the microscope, through a second lens and finally into the eye of the microscope user. By this time, the image on the slide has been magnified many times.
Most light microscopes have a variety of lenses that allow a user to see objects under different magnifications. Each lens is a different magnification and a different distance from the stage. Lower magnification lenses are further from the stage, meaning they observe a larger area and allow in more light. Higher magnification lenses are much closer to the stage. In fact, at the highest resolutions, the lens is separated from the specimen by just a thin layer of oil. Since the lens is so close, the user sees a much smaller area, and less light enters the microscope and the eye. The differing amounts of light reaching the eye make the field of view brighter or dimmer.Learn more about Optics & Waves
In microscopy, the depth of field refers to the range of distance that runs parallel to the optical axis where the specimen can move and still be viewed without negatively affecting the clarity of the object under observation. The depth of field determines the vertical extent of the plane of focus, which is typically measured in microns.Full Answer >
The low-power objective on a microscope is the shortest or second shortest objective lens found on standard laboratory microscopes. Low-power objective lenses typically add 10x to the magnifying power of the microscope.Full Answer >
Symptoms of hypothyroidism or low thyroid hormone production include coarse hair, dry skin, slow body movements, inability to tolerate cold, constipation, and feeling sluggish or weak, explains WebMD. Rarer symptoms include an enlarged thyroid gland, weight gain, swelling in the hands and feet, and muscle aches.Full Answer >
Having a low body mass index (BMI) can be associated with certain health risks and problems like osteoporosis, anemia related to iron deficiency, loss of menstruation and infertility, explains WebMD. A person with a BMI below 18.5 is considered underweight. Causes for being underweight can include being sick, a medical problem, stress, being malnourished or too much dieting.Full Answer >