Bushnell Telescope Q and A Instruction Manual

Telescope Q & A’s

Q: Why is the image in the telescope upside down and
reversed from right to left?
A: An upside down and reversed image is a common
characteristic of most astronomical telescopes. Since
telescopes are used for astronomical viewing orientation is
not important. The image in the finderscope will also be
upside down and reversed.

Q: How do I determine the power of my telescope?
A: The power of your telescope can be determined by
dividing the focal length of the objective lens by the focal
length of the eyepiece. The eyepiece focal length is the
number printed on the eyepiece. (For example: 1000
divided by 25=40X)

Q: What can I see with my telescope?
A: Telescopes with power ranging from 25X to 50X can be
used to view Star Clusters and Nebulae. 90X to 120X
telescopes can view galaxies. Most planets can be seen at
150X and higher.

Q: What do the numbers on the eyepiece mean?
A: The numbers of the eyepiece represent the focal length
of the eyepiece.

Q: What is the difference between a Refractor Telescope
and a Reflector Telescope?
A: Refractor telescopes use lenses only (no mirrors or
prisms). The refractor is essentially a closed tube design.
It is mechanically uncomplicated and basically
maintenance free. Refractors are generally used for
astronomical viewing; however, they can be used for
terrestrial purposes beyond 100 feet.

Reflector telescopes primarily use mirrors rather than
lenses and prisms. Light enters through the front objective
lens, travels the length of the tube to the main mirror then
travels back to a flat second mirror. At this point, the
eyepiece lens magnifies the image. The advantage of
reflectors is that they generally offer brighter images for
deep sky viewing due to their greater light gathering ability.
Reflectors are designed for astronomical viewing.

Light path through a refractor.

Light path through a reflector.