To reduce distortions such as elongations and blurriness caused by the curvature of the "objective" lens—the convex lens at the far end of the telescope—Galileo ground a lens larger than he ...

If you're keen on dual-purpose 'bins' for daytime birdwatching and moongazing, consider ones with large light-gathering objective lenses. Our current number one binocular is Celestron's Nature DX ...

With 12x magnification and 50mm objective lenses, at first glance the Celestron Nature DX ED 12x50 is exactly the right size of binoculars to consider for both safari and stargazing. However ...