Two key inventions enabled astronomers to overcome the problem of chromatic aberration: the invention of the reflecting telescope described by James Gregory and built in a different form by Isaac ...

This was the first working reflecting telescope. Other designers proved unable to grind mirrors with a regular curvature, so the reflector remained largely a curiosity until the mid-18th century ...

AS time passes and astronomical work advances there is a greater demand, year by year, for more powerful instruments of research. Fortunately, instrument makers have so far been able to fulfil the ...

His original reflecting telescope, which he built himself in 1668, was just six inches long. This modest device not only eliminated the colored fringes but magnified whatever it focused on by 40 ...

The Stephens observatory, located on the roof of Carnegie, houses a 12-inch Newtonian reflecting telescope, built by Roscoe G. Stephens of Kennebunk, Maine. Stephens gifted the telescope to the ...

A multi-layer film of dielectrics on top of aluminum is used to enhance the reflectance in the visible or ultraviolet regions. Telescopes can be categorized in three optical design types. Reflecting: ...

From lens focal lengths and fill-flash to portraits, macro or stunning landscapes there are techniques for everyone. Learn how to use metering, considering composition and shoot everything from ...

Isaac Newton was the first to really make it work. Newton's reflecting telescope consisted of a single curved main mirror, ...

Should you buy a telescope with a refracting lens or a reflecting mirror? It depends on what you want to look at, and your ...