Download Below is a table of advantages and disadvantages of different types

Survey
yes no Was this document useful for you?
   Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Document related concepts

XMM-Newton wikipedia, lookup

Allen Telescope Array wikipedia, lookup

Hubble Space Telescope wikipedia, lookup

Arecibo Observatory wikipedia, lookup

Lovell Telescope wikipedia, lookup

Spitzer Space Telescope wikipedia, lookup

James Webb Space Telescope wikipedia, lookup

International Ultraviolet Explorer wikipedia, lookup

Optical telescope wikipedia, lookup

Very Large Telescope wikipedia, lookup

CfA 1.2 m Millimeter-Wave Telescope wikipedia, lookup

Reflecting telescope wikipedia, lookup

Transcript
Below is a table of advantages and disadvantages of different types of telescopes.
The writing in red is in the wrong place can you put it into the correct place on the
table?
Type of telescope
Refractor
Advantages
Disadvantages
Easy to use and reliable with
little or no maintenance.
High contrast images with no
secondary mirror or diagonal
obstruction.
Excellent for faint deep sky
objects such as remote
galaxies, nebulae and star
clusters.
Colour correction is good.
Sealed optical tube reduces
image degrading air currents
and protects optics.
Objective lens is permanently
mounted and aligned
More expensive.
Heavier, longer and bulkier.
Focal ratios are usually long
making photography of deep sky
objects more difficult.
Some colour aberration in
achromatic designs (doublet).
More expensive than Newtonians
of equal aperture.
Reflector Newtonian
Lowest cost since mirrors can
be produced at less cost than
lenses in medium to large
apertures.
Reasonably compact and
portable.
Best all-around, all-purpose
telescope design.
Reasonably good for lunar and
planetary work but good for
deep sky astrophotography.
Low in optical aberrations
delivering a very bright image.
Slight light loss due to secondary
(diagonal) obstruction when
compared with refractors
Less suited for viewing small
and faint deep sky objects such
as distant galaxies and nebulae
because of practical aperture
limitations.
Reflector Cassegrain
Excellent for lunar, planetary
and binary star observations.
Good for distant terrestrial
viewing.
Excellent optics with razor
sharp images over a wide field.
Useful for all types of
photography.
Closed tube design reduces
image degrading air currents.
Most are extremely compact
and portable.
Easy to use, durable and
virtually maintenance free.
Large apertures at reasonable
prices and less expensive than
equivalent aperture refractors.
Best near focus capability of
any type telescope.
Most versatile type of
telescope.
It is not what people expect a
telescope to look like.
Slight light loss due to secondary
mirror obstruction compared to
refractors.
Generally not suited for terrestrial
applications.