Image point (focus)

Definition

The image point, or focus, is where light rays converge after passing through a lens or reflecting off a mirror. In microscopy, it is essential for obtaining a sharp and clear view of the specimen.

5 Must Know Facts For Your Next Test

1. The focus determines the clarity and resolution of the microscopic image.
2. Adjusting the focus involves moving the stage or objective lens to bring the specimen into clear view.
3. Microscopes typically have coarse and fine focus knobs for initial and precise adjustments respectively.
4. Proper focusing minimizes spherical aberration and chromatic aberration in microscopy.
5. Immersion oil can be used with certain objective lenses to improve focus by reducing light refraction.

Related terms

Objective Lens:

A lens closest to the specimen that magnifies the image.

Resolution:

The ability to distinguish two close objects as separate entities.

Spherical Aberration: A distortion of an image caused by light rays not converging at a single point.