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Newton and Galilei


Reflector or Lens?

Galileo Galilei
Among astronomers as well as lighting engineers, there has always been controversy about whether lenses or mirrors (reflectors) are better suited to collect light. Galileo Galilei, the founder of modern physics, constructed a lens telescope with which he discovered the moons of Jupiter. 60 years later, Isaac Newton, the brilliant mathematician and originator of the law of gravitation, developed a reflector telescope with an ingeniously calculated concave mirror that was to become the prototype of all flashlight reflectors.

Sir Isaac Newton
Towards the end of the 19th century, when flashlights first conquered the market, they were only equipped with lenses. From 1950 onwards, reflectors (mirrors) gradually replaced lenses, not least because of their low manufacturing cost.

Lens or Reflector
Conventional flashlight reflectors are made from plastics and undergo a coating process while modern LED reflectors consist of die-cast acrylic and are called collimators. But even these reflectors can be traced back to Newton. Strictly speaking, there has been nothing new under the sun for almost 350 years. What are the capacities of these systems?