Determining Field of View, General Observing Hints

Although the power is variable, each instrument under average skies has a limit to the highest useful magnification. The general rule is that 60 power can be used for every inch of aperture. For example, the C6-R is 6 inches in diameter. Multiplying 6 by 60 gives a maximum useful magnification of 360 power. Although this is the maximum useful magnification, most observing is done in the range of 20 to 35 power for every inch of aperture which is 120 to 210 times for the C6-R telescope.

Determining Field of View

Determining the field of view is important if you want to get an idea of the angular size of the object you are observing. To calculate the actual field of view, divide the apparent field of the eyepiece (supplied by the eyepiece manufacturer) by the magnification. In equation format, the formula looks like this:

Apparent Field of Eyepiece

True Field = 

Magnification

As you can see, before determining the field of view, you must calculate the magnification. Using the example in the previous section, we can determine the field of view using the same 20mm eyepiece. The 20mm eyepiece has an apparent field of view of 50°. Divide the 50° by the magnification, which is 60 power. This yields an actual field of .83°, or nearly a full degree.

To convert degrees to feet at 1,000 yards, which is more useful for terrestrial observing, simply multiply by 52.5. Continuing with our example, multiply the angular field .83° by 52.5. This produces a linear field width of 43.6 feet at a distance of one thousand yards. The apparent field of each eyepiece that Celestron manufactures is found in the Celestron Accessory Catalog (#93685).

General Observing Hints

When working with any optical instrument, there are a few things to remember to ensure you get the best possible image.

•Never look through window glass. Glass found in household windows is optically imperfect, and as a result, may vary in thickness from one part of a window to the next. This inconsistency can and will affect the ability to focus your telescope. In most cases you will not be able to achieve a truly sharp image, while in some cases, you may actually see a double image.

•Never look across or over objects that are producing heat waves. This includes asphalt parking lots on hot summer days or building rooftops.

•Hazy skies, fog, and mist can also make it difficult to focus when viewing terrestrially. The amount of detail seen under these conditions is greatly reduced. Also, when photographing under these conditions, the processed film may come out a little grainier than normal with lower contrast and underexposed.

•If you wear corrective lenses (specifically glasses), you may want to remove them when observing with an eyepiece attached to the telescope. When using a camera, however, you should always wear corrective lenses to ensure the sharpest possible focus. If you have astigmatism, corrective lenses must be worn at all times.

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.