14
15
through the murk of light pollution. Even bright nebulae like the Orion and
Lagoon Nebulae lose much of their delicate detail. The Moon and planets are
not affected; they require steady air more than dark skies, so they remain good
targets for city-dwelling observers.
The International Dark-Sky Association is waging the fight against light pol-
lution. The IDSA was founded in 1988 with the mission of educating the
public about the adverse impact that light pollution has on the night sky and
astronomy. Through educational and scientific means, the nonprofit IDA works
to raise awareness about the problem and about measures that can be taken
to solve it.
Do you need help dealing with local officials to control street or building light-
ing in your area? The IDA’s extensive support materials can show you how.
Help preserve dark skies, join the IDA today! For information, write to IDA, 3225
N. First Ave., Tuscon, AZ 85719-2103 or visit their website: www.darksky.org.
The best way to avoid immediate problems with light pollution, however, is to
take your telescope to where there are dark skies. You will be amazed at how
many stars you can see when you get away from the city lights.
Do You Wear Eyeglasses?
If you wear eyeglasses, you may be able to keep them on while you observe.
In order to do this, your eyepiece must have enough “eye relief” to allow you
to see the entire field of view with glasses on. You can try looking through the
eyepiece first with your glasses on and then with them off, to see if the glasses
restrict the view to only a portion of the full field. If the glasses do restrict the
field of view, you may be able to observe with your glasses off by just refocus-
ing the telescope to your unaided vision.
If your eyes are astigmatic, images will probably appear best with glasses on.
This is because a telescope’s focuser can accommodate for nearsightedness
or farsightedness, but not astigmatism. If you have to wear your glasses while
observing and cannot see the entire field of view, you may want to purchase
additional eyepieces that have longer eye relief.
care and Maintenance
If you give your telescope reasonable care, it will last a lifetime. Store it in a
clean, dry, dust-free place, safe from rapid temperature changes and humidity.
Do not store the telescope outdoors, although storage in a garage or shed is
OK. Small components like eyepiece and other accessories should be kept in
a protective box or storage case. Keep the dust caps on the front of the scope
and on the focuser when it is not in use.
The telescope requires very little mechanical maintenance. The optical tube is
made of steel and has a smooth painted finish that is fairly scratch resistant.
If a scratch does appear on the tube, it will not harm the telescope. Smudges
on the tube can be wiped off with e soft cloth and a household cleaner such
as Windex or Formula 409.
Refer to Appendix B for detailed instructions on how to clean the optics of the
FunScope.
specifications
Primary mirror diameter:
76mm
Primary mirror diameter:
Spherical
Secondary mirror minor axis:
28mm
Focal length:
300mm
Focal Ratio:
f/3.9
Mirror Coatings:
Aluminum with SiO
2
overcoat
Focuser:
Rack-and-pinion, accepts 1.25" eyepieces
Eyepieces:
20mm and 10mm, 1.25"
Magnification:
15x (with 20mm), 30x (with 10mm)
Finder:
Red-dot finder reflex sight
Weight:
4 lbs.
Tube Length:
10.25"
Tube Outer Diameter:
3.8"
Do You Wear Eyeglasses?
If you wear eyeglasses, you may be able to keep them on
while you observe. In order to do this, your eyepiece must
have enough “eye relief” to allow you to see the entire
field of view with glasses on. You can try looking through
the eyepiece first with your glasses on and then with them
off, to see if the glasses restrict the view to only a portion
of the full field. If the glasses do restrict the field of view,
you may be able to observe with your glasses off by just
refocusing the telescope to your unaided vision.
If your eyes are astigmatic, images will probably appear
best with glasses on. This is because a telescope’s
focuser can accommodate for nearsightedness or
farsightedness, but not astigmatism. If you have to
wear your glasses while observing and cannot see the
entire field of view, you may want to purchase additional
eyepieces that have longer eye relief.
Short eye relief restricts the
field of view for eyeglass
wearers.
Long eye relief allows full field
of view to be seen with or
without eyeglasses.