Camera lens attachment designed to allow the primary lens to focus more closely that it would focus independently. Depending on manufacturer, the lens may be called a micro-lens or macro-lens. Quality of the lens is associated with image quality. Single element lenses are less expensive but show aberrations (e.g., chromatic aberrations). Double element lenses are more expensive, but are designed to reduce the degree of aberration.
close-up lens
Synonyms: micro-lens, macro-lens