Telescope Maintenance • 57
T E L E S C O P E M A I N T E N A N C E
While the G-8 telescope requires little maintenance, there are a few things to
remember that will ensure your telescope performs at its best.
Occasionally, dust and/or moisture may build up on the corrector plate of your
telescope. Special care should be taken when cleaning any instrument so as
not to damage the optics.
If dust has built up on the corrector plate, remove it with a brush (made of
camel’s hair) or a can of pressurized air. Spray at an angle to the lens for
approximately two to four seconds. Then, use an optical cleaning solution and
white tissue paper to remove any remaining debris. Apply the solution to the
tissue and then apply the tissue paper to the lens. Low pressure strokes
should go from the center of the corrector to the outer portion.
Do NOT rub in
circles!
You can use a commercially made lens cleaner or mix your own. A good
cleaning solution is isopropyl alcohol mixed with distilled water. The solution
should be 60% isopropyl alcohol and 40% distilled water. Or, liquid dish soap
diluted with water (a couple of drops per one quart of water) can be used.
Occasionally, you may experience dew build-up on the corrector plate of your
G-8 during an observing session. If you want to continue observing, the dew
must be removed, either with a Celestron Dew Eliminator (# 94122) or by
pointing the telescope at the ground until the dew has evaporated. The
optional Dew Cap/Lens Shade (#94017) helps reduce the amount of dew build-
up on the corrector plate.
If moisture condenses on the inside of the corrector, place the telescope in a
dust-free environment and point it down. Remove the accessories from the rear
cell of the telescope or spotting scope to allow the moisture to evaporate from
the optical tube.
To minimize the need to clean your telescope, replace all lens covers once you
have finished using it. Since the rear cell is
NOT
sealed, the cover should be
placed over the opening when not in use. This will prevent contaminants from
entering the optical tube.
Internal adjustments and cleaning should be done only by the Celestron repair
department. If your G-8 is in need of internal cleaning, please call the factory
for a return authorization number and price quote.
The optical performance of your Celestron telescope is directly related to its
collimation, that is the alignment of its optical system. Your G-8 was colli-
mated at the factory after it was completely assembled. However, if the
telescope is dropped or jarred severely during transport, it may have to be
recollimated. The only optical element that can be adjusted by you is the tilt of
the secondary mirror.
Care and Cleaning
of the Optics
Collimation
