Telescopes Flashcards
(14 cards)
What are the three main types of telescopes?
Newtonians, refractors and catadioptric telescopes
Which type of telescope normally has the highest focal length?
Catadioptric telescopes
Which telescopes produce diffraction spikes
Newtonians
What was the first telescope type?
Reflector telescope
How many lenses do most high quality refractor telescopes?
Any where from two to five lenses
What type of glass are high quality refractors made from?
ED glass which stands for extra low dispersion glass.
How does a Newtonian telescope work?
By using mirrors to reflect the light down a tube.
What is the aperture of a telescope?
The size/diameter of the lens of mirror, a larger aperture can collect more light.
What is the focal length of a telescope?
The length from where the light enters the telescope to where it reaches focus. The higher the focal length is the more zoomed in it is.
How does a refractor work?
By refracting light with lenses.
How can you work out the magnification of a telescope?
The focal length of the telescope divided by the focal length of the eyepiece.
What is normally considered a short focal length telescope?
Any where from 400mm of lower.
What is considered a high focal length telescope?
A telescope with a focal length of above 1000mm.
What do you need the highest focal length when taking a picture of an object for?
Planets and galaxies.
