Thanks to the revolutionary optical concept, ZEISS has managed to fit the performance of a 56x lens into a significantly lighter and more compact design. The result: impressively bright images until late into the evening, unprecedented ergonomics and large eye-relief. With these binoculars dawn and dusk are no challenge. No matter the light conditions, you will see your birds or wildlife. 10x means it is great across long distances as well. Excellent for astronomy.