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6. Using the accessories, a bit of math to
understand how all it works.
Using the accessories is easy and fun. To
change magnification simple swap eyepieces.
To get more magnification simply use the
barlow lens. But how all of this work?
6.1. Power (magnification)
Your telescope as a focal length of 800mm.
This is approximately the distance between
the telescope lens to its focal point (very
similar to the distance between the focus
point of a loupe and the loupe lens). This is a
very important feature that allows to
determine several interesting facts such as
magnification.
The magnification is determined by the
telescopes focal length and the used
eyepiece. You probably noticed that the three
supplied eyepieces are PL25mm, PL12mm and
PL6mm. This means that the PL25mm is a
25mm focal length eyepiece while the PL6mm
is a 6mm focal length eyepiece.
To determine the magnification just devide
the telescope focal length by the eyepiece
focal length. Lets give an example for our
telescope and the supplied eyepieces:
Telescope focal length is 800mm
PL25 eyepiece focal length is 25 mm
800𝑚𝑚
25𝑚𝑚 =32 𝑝𝑜𝑤𝑒𝑟
This means that the PL25mm eyepiece
provides a 32x power (magnification). This
seems low but try it, you will see a a bright
image with some very good detail.
6.2. Barlow Lens (not included)
The barlow lens is a very interesting device. It
is a negative lens that multiplies the
telescopes focal length. So a 2x
Barlow multiplies the original focal
length by 2x, in this case
800𝑚𝑚 𝑥 2 = 1600𝑚𝑚.
A 3x Barlow lens multiplies by 3x.
When used with the PL25mm
eyepiece you get 3x the power
obtained before
32 𝑝𝑜𝑤𝑒𝑟 𝑋 3𝑥 𝐵𝑎𝑟𝑙𝑜𝑤 = 96 𝑝𝑜𝑤𝑒𝑟
6.3. Erecting lens (not included)
The erecting lens gets you a upright image
view with the telescope. It also adds some
power like the barlow lens. The supplied
Erecting Lens provides and extra 1.5x power.
6.4. Diagonal Mirror (does not apply to
this telescope model)
This diverts the light coming from the
telescope to an angle of 45 or 90 degrees. It is
useful because it provides a more confortable
position when observing.
Here are some examples on how to use the
accessories.
Some possible accessory combinations