Telescope Maintenance • 63
T E L E S C O P E M A I N T E N A N C E
While your CM-1100 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
telescope during an observing session. If you want to continue observing, the
dew must be removed, either with a hair dryer or by pointing the telescope at
the ground until the dew has evaporated.
If moisture condenses on the inside of the corrector, remove the accessories
from the rear cell of the telescope. Place the telescope in a dust-free environ-
ment and point it down. This will remove the moisture from the telescope 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 telescope is in need of internal cleaning, please call the
factory for a return authorization number and price quote.
The optical performance of your Celestron CM-1100 telescope is directly
related to its collimation, that is the alignment of its optical system. Your
Celestron CM-1100 was collimated at the factory after it was completely
assembled. However, if the telescope is dropped or jarred severely during
transport, it may have to be collimated. The only optical element that may
need to be adjusted, or is possible, is the tilt of the secondary mirror.
To check the collimation of your telescope you will need a light source. A
bright star near the zenith is ideal since there is a minimal amount of atmo-
Care and Cleaning
of the Optics
Collimation
