Question

while viewing a slide with the $X objective lens, you notice an interesting specimen and would like to zoom in on it. You switch to the 40X objective lens. However, your specimen is no longer seen in the field of view even after adjusting focus. What happened. How could you prevent this?

Answer 1

The light refracted or bent when it is passed from one object to other such as from air to a glass slide. The space between the microscope objective lens and the slide is filled with air and the light is refracted and scatters and it is lost. This is because of difference in refractive index of air and glass slide. The refractive index of air is approximately 1.0, while the refractive index of glass is approximately 1.5. The refraction of light at different wavelengths result in different angles thus, the objects are magnified as big.

Using a lower magnification microscope objective lense such as 4x or 10x, or 40x mau result in the light refraction which is not usually noticeable. When using the 100x objective lens, the light refraction through dry lens is noticeable. Reducing the amount of light refraction allows more light to pass through the microscope slide and will be directed through the very narrow diameter of a higher power objective lens. More light produces more clear image. Usings immersion oil having refractive index equal to that of the glass slide allows more light is directed through the objective and a clearer image is observed. Therefore, when switched from 4X objective to 40X objective, the refraction of light becomes more and image is not clear.