Celestron CR-150 HD T E L E S C O P E M A I N T E N A N C E, Care and Cleaning of the Optics

T E L E S C O P E M A I N T E N A N C E

Care and Cleaning of the Optics

Refractors are generally very low maintenance telescopes. Cleaning is really all that is needed, and even that is minimal if the telescope is stored properly.

Occasionally, dust and/or moisture may build up on the objective lens 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 objective lens, remove dust with a camel’s hair brush or a can of pressurized air. Spray at an angle to the lens for approximately 2 to 4 seconds. Then, use optical cleaning solution and white tissue paper to remove any remaining debris. Strokes should go from the center of the objective lens to the outer portion. Do NOT rub in circles! With refractive lenses, never apply the cleaning solution directly to the lens. Because the elements are air-spaced, excess solution may seep between the lenses. Apply the solution to the tissue, then the tissue to the lens.

You can use 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 objective lens of your telescope during an observing session. This may be removed with a hair dryer or by pointing the telescope at the ground. Since your Celestron refractor has a built-in dew cap, the dewing process is slightly reduced. If moisture condenses on the inside of the lens, remove the accessories from the telescope. Place the telescope in a dust-free environment 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 back of the telescope where the accesso- ries attach is NOT sealed, the plastic cap should be placed over the opening when not in use. This will prevent contaminates from entering the optical tube.

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