Optical microscopes work by using visible light and a system of lenses to magnify the image of a specimen, allowing you to see details that are invisible to the naked eye.
Here's a breakdown of the process:
- Illumination: A light source, usually a lamp, provides the light that illuminates the specimen.
- Condenser: The condenser lens focuses the light onto the specimen, ensuring even illumination and improving image resolution.
- Objective Lens: The objective lens is the primary magnifying lens. It gathers light that has passed through the specimen and creates a magnified, real image. Different objective lenses offer varying levels of magnification (e.g., 4x, 10x, 40x, 100x).
- Eyepiece Lens (Ocular Lens): The eyepiece lens further magnifies the real image projected by the objective lens, creating a virtual image that you see. The eyepiece typically magnifies 10x.
- Image Formation: The light passes through the specimen, is bent (refracted) by the lenses, and ultimately creates a magnified image that your eye can perceive. The total magnification is calculated by multiplying the magnification of the objective lens by the magnification of the eyepiece lens.
In simpler terms:
- Light shines through or bounces off the sample.
- The objective lens magnifies the light that passes through the sample.
- The eyepiece further magnifies this image, projecting it into your eye.
Important Considerations:
- Specimen Preparation: Often, specimens need to be prepared for viewing under a microscope. As noted in the reference, cells are typically transparent, so staining techniques are often used to enhance contrast and reveal details. However, staining often kills the cells.
- Resolution: Resolution is the ability to distinguish between two closely spaced objects. Optical microscopes have a limited resolution due to the wavelength of visible light.
- Magnification vs. Resolution: Increasing magnification without improving resolution will only result in a larger, blurry image.
