Ads
related to: telescope lens size chart comparison women s kids
Search results
Results from the WOW.Com Content Network
Telecompressor or focal reducer: Optical element to decrease the telescope's focal length and magnification (usually by a fixed percentage) and widen the field of view, providing opposite effects of a Barlow lens. Star Diagonal: Used to change the angle of the light coming out of a telescope, for easier viewing.
This is a list of large optical telescopes. For telescopes larger than 3 meters in aperture see List of largest optical reflecting telescopes . This list combines large or expensive reflecting telescopes from any era, as what constitutes famous reflector has changed over time.
Since a lens can only be held in place by its edge, the center of a large lens sags due to gravity, distorting the images it produces. The largest practical lens size in a refracting telescope is around 1 meter (39 in). [35] There is a further problem of glass defects, striae or small air bubbles trapped within the glass.
Some telescopes are classified by the task they perform; for example Solar telescopes are all designs that look at the Sun, Dobsonian telescopes are designed to be low cost and portable, Aerial telescopes overcame the optical shortcomings of 17th-century objective lenses, [1] etc.
The Swedish 1-m Solar Telescope, with a lens diameter of 43 inches, is technically the largest, with 39 inches clear for the aperture.The second largest refracting telescope in the world is the Yerkes Observatory 40 inch (102 cm) refractor, used for astronomical and scientific observation for over a century.
Comparison of nominal sizes of apertures of some notable optical telescopes For the largest reflecting telescopes on the planet, the horizontal indicates the year built and the vertical direction indicates the size of the mirror measured in meters. Countries which contain several of these telescopes are color-coded for identification.
Ads
related to: telescope lens size chart comparison women s kids