Definition

1. Noun:
   • The lens or system of lenses in an optical instrument (like a telescope or microscope) that is positioned closest to the object being observed. It is the primary lens that first receives light from the object and forms an initial image.

Usage

• The term "object glass" is a technical term used primarily in optics and the description of scientific instruments. It is synonymous with "objective" or "objective lens." It specifies the component that faces the specimen or distant object.

Examples

• Noun:
  • The quality of the object glass determines the clarity and magnification of the image in a microscope.
  • Astronomers carefully clean the object glass of the telescope to avoid any distortions in their observations.

Advanced Usage

• Historical Context: The term "object glass" was more common in older scientific literature. In modern usage, "objective lens" or simply "objective" is more frequent.
  • In his 19th-century notes, the inventor referred to the "object glass" of his prototype.

Variants and Related Words

• Objective (lens) (n): The modern, more common term for an object glass.
  • The microscope has three different objectives for varying levels of magnification.
• Eyepiece (n): The lens or group of lenses in an optical instrument closest to the viewer's eye, which magnifies the image formed by the object glass.
  • After passing through the object glass, the light enters the eyepiece.

Synonyms

• Objective lens: The lens assembly closest to the object.
• Front lens: A less technical term emphasizing its position.

Notes

• "Object glass" is a compound noun. It is crucial to distinguish it from other optical components like the "eyeglass" (a lens for vision correction) or the "eyepiece." Its function is specifically to collect light from the object.

Noun

1. the lens or system of lenses in a telescope or microscope that is nearest the object being viewed