Photography Hints, Field of View, Metering

Field of View

Determining the field of view is important if you want to get an idea of the 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 (in degrees) =

Magnification

Using the example we started with in the previous section, we can determine the field of view using the same 25mm eyepiece. The 25mm eyepiece has an apparent field of view of 50°. Divide the 50° by the magnification, which is 20 power. This yields an actual field of 2.5°, or two and a half degrees. To convert this to feet at one thousand yards, multiply the actual field of 2.5° by 52.5. This gives us a field width of 131 feet at one thousand yards.

PHOTOGRAPHY HINTS

Metering

Celestron spotting scopes have fixed apertures and, as a result, fixed f/ratios. To properly expose your subjects photographically, you need to set your shutter speed accordingly. Most 35mm SLR cameras offer through-the-lens metering which lets you know if your picture is under or overexposed. Adjustments for proper exposures are made by changing the shutter speed. Consult your camera manual for specific information on metering and changing shutter speeds.

Reducing Vibration

Releasing the shutter manually can cause vibrations, producing blurred photos. To reduce vibration when tripping the shutter, use a cable release. A cable release keeps your hands clear of the camera and lens, thus eliminating the possibility of introducing vibration. Mechanical shutter releases can be used, though air-type releases are best.

Blurry pictures can also result from shutter speeds that are too slow. To prevent this, use films that produce shutter speeds greater than 1/250 of a second when hand-holding the lens. If the lens is mounted on a tripod, the exposure length is virtually unlimited.

Another way to reduce vibration is with the Vibration Suppression Pads (#93503). These pads rest between the ground and tripod feet. They reduce the vibration amplitude and vibration time.

52270, 52260 specifications

Celestron, a leading manufacturer in the field of telescopes and astronomy equipment, has consistently delivered top-notch products tailored for both amateur enthusiasts and seasoned astronomers. Among its impressive lineup are the Celestron 52260 and Celestron 52270 models, known for their exceptional performance and user-friendly features.

The Celestron 52260, commonly referred to as the Astromaster 70AZ telescope, is an ideal choice for beginners. It features a 70mm aperture that provides bright and clear images of celestial objects, making it perfect for viewing the moon, planets, star clusters, and nebulae. The telescope's simple, lightweight design ensures easy portability and quick setup, allowing users to take it virtually anywhere. It comes with a StarPointer finderscope that assists in locating objects in the night sky with ease.

The Celestron 52270, also known as the Astromaster 90AZ telescope, boasts a 90mm aperture, which offers even clearer and more detailed views of distant astronomical wonders. This model enhances the viewing experience with its superior light-gathering capabilities, delivering sharper images. Like its counterpart, the 52270 features an adjustable aluminum tripod, providing a stable platform for observations.

Both telescopes incorporate Celestron's premium optics, including fully coated glass optics that maximize light transmission and reduce glare. Furthermore, they are designed with an easy-to-use Altazimuth mount, facilitating smooth movement in both horizontal and vertical directions. This feature enables users to track celestial objects with precision, making the observing experience enjoyable and hassle-free.

Another notable characteristic of both models is their adaptability; the telescopes are compatible with various 1.25" eyepieces, allowing users to enhance their viewing options and customize their observations. Additionally, they are equipped with the Celestron's innovative SkyX software, which provides a comprehensive database of celestial objects, aiding both novice and advanced stargazers in their explorations.

In summary, the Celestron 52260 and 52270 telescopes are exemplary choices for anyone looking to delve into the universe of astronomy. With their robust features, user-friendly designs, and exceptional optical performance, these models serve as excellent entry points for individuals eager to explore the wonders of the night sky. Whether for casual stargazing or deeper astronomical pursuits, Celestron's commitment to quality and innovation makes their telescopes a valuable asset for any skywatcher.