Fotographic objective by Josef Petzval (1807-91) (Austria 1973)

Stamp Fotographic objective by Josef Petzval (1807-91) it reflects the thematic directions:

An optical instrument is a device that processes light waves (or photons), either to enhance an image for viewing or to analyze and determine their characteristic properties. Common examples include periscopes, microscopes, telescopes, and cameras.

Photography is the art, application, and practice of creating images by recording light, either electronically by means of an image sensor, or chemically by means of a light-sensitive material such as photographic film. It is employed in many fields of science, manufacturing (e.g., photolithography), and business, as well as its more direct uses for art, film and video production, recreational purposes, hobby, and mass communication. A person who captures or takes photographs is called a photographer.

A conference is a meeting, often lasting a few days, which is organized on a particular subject, or to bring together people who have a common interest. Conferences can be used as a form of group decision-making, although discussion, not always decisions, is the primary purpose of conferences. The term derives from the word confer.