Care and Cleaning of the Optics

While your 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 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 lens, 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 lens 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 lens of your telescope during an observing session. If you want to continue observing, the dew must be removed, either with a hair dryer (on low setting) or by pointing the telescope at the ground until the dew has evaporated.

If moisture condenses on the inside of the lens, remove the accessories from the rear cell of 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 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.

Collimation

Collimation is the process of aligning the optical axis of each optical element with each other and with the mechanical axis of the telescope tube. For a refractor telescope design this means aligning the optical axis of the objective lens with the optical axis of the eyepiece on the other end of the tube. Your C6-R refractor was properly aligned at the factory, however rough handling while traveling may eventually alter the alignment of the lens. Your Celestron refractor telescope comes with a fully adjustable objective lens housing to ensure proper alignment of the optical axis.

To determine whether or not re-collimation is necessary, the telescope should be set up outside at night. It should be a still night and one in which you have let the telescope

Collimation Screws (Allen head)

Mounting Screws (Phillips head)

Figure 8-1 – Objective lens housing (with lens shade removed) show mounting and collimation screws.

Advanced Series GT, C6-R, C6-RGT specifications

The Celestron C6-RGT and C6-R models, part of the Advanced Series GT lineup, are popular choices for amateur astronomers seeking high-quality optics and reliable features. The C6-RGT, equipped with a 6-inch refractor, is designed for both visual and astrophotographic pursuits. Its impressive features make it a great option for anyone looking to explore the night sky in greater detail.

One of the standout characteristics of the C6-RGT is its large 6-inch aperture, which allows for exceptional light-gathering capability. This feature is crucial for viewing faint celestial objects, giving users the ability to observe details in nebulae, galaxies, and star clusters. The refractor design minimizes chromatic aberration, ensuring sharp and clear images across a wide range of viewing conditions.

The telescope comes with a fully multi-coated optics system that enhances light transmission and contrast, creating brighter and clearer images. The C6-R is also designed with a robust aluminum tube that not only ensures durability but also helps maintain stability during long observing sessions.

The Advanced Series GT mount is another essential element of the C6-RGT and C6-R models. This computerized mount features a sturdy, stable design that supports a wide range of telescopes while providing smooth tracking of celestial objects. The GoTo technology allows users to locate and track over 40,000 celestial objects with ease. This high level of automation is particularly helpful for beginners who may be unfamiliar with the night sky.

Another notable feature of the Advanced Series GT is its ability to be controlled through a smartphone or tablet, thanks to Celestron's SkyPortal app. This integration opens doors for enhanced stargazing experiences, offering customizable tours and educational information right at your fingertips.

In terms of usability, both models have a comfortable height and the mount can be easily adjusted to accommodate various observing positions. The telescope is also portable, making it convenient for outreach events or trips to dark-sky locations.

Overall, the Celestron C6-RGT and C6-R models, with their combination of powerful optics, advanced technology, and user-friendly features, represent an excellent choice for both budding astronomers and passionate enthusiasts. With Celestron’s commitment to quality and innovation, these telescopes promise to deliver unforgettable views of the wonders of the universe.