Piggyback

After looking at the night sky for a while you may want to try photographing it. Several forms of photography are possible with your telescope, including terrestrial and celestial photography. Both of these are discussed in moderate detail with enough information to get you started. Topics include the accessories required and some simple techniques. More information is available in some of the publications listed at the end of this manual.

In addition to the specific accessories required for each type of celestial photography, there is the need for a camera - but not just any camera. The camera does not have to have many of the features offered on today's state-of-the-art equipment. For example, you don't need auto focus capability or mirror lock up. Here are the mandatory features a camera needs for celestial photography. First, a “B” setting which allows for time exposures. This excludes point and shoot cameras and limits the selection to SLR cameras, the most common type of 35mm camera on the market today.

Second, the “B” or manual setting should NOT run off the battery. Many new electronic cameras use the battery to keep the shutter open during time exposures. Once the batteries are drained, usually after a few minutes, the shutter closes, whether you were finished with the exposure or not. Look for a camera that has a manual shutter when operating in the time exposure mode. Olympus, Nikon, Minolta, Pentax, Canon and others have made such camera bodies.

The camera must have interchangeable lenses so you can attach it to the telescope and so you can use a variety of lenses for piggyback photography. If you can't find a new camera, you can purchase a used camera body that is not 100-percent functional. The light meter, for example, does not have to be operational since you will be determining the exposure length manually.

You also need a cable release with a locking function to hold the shutter open while you do other things. Mechanical and air release models are available.

The easiest way to enter the realm of deep-sky, long exposure astrophotography is via the piggyback method. Piggyback photography is done with a camera and its normal lens riding on top of the telescope. Through piggyback photography you can capture entire constellations and record large scale nebulae that are too big for prime focus photography. Because you are photographing with a low power lens and guiding with a high power telescope, the margin for error is very large. Small mistakes made while guiding the telescope will not show up on film. To attach the camera to the telescope, use the piggyback adapter screw located on the top of the tube mounting ring. It may be necessary to remove the finder scope bracket before attaching the camera.

As with any form of deep-sky photography, it should be done from a dark sky observing site. Light pollution around major urban areas washes out the faint light of deep-sky objects. You can still practice from less ideal skies.

1.Polar align the telescope (using one of the methods described earlier) and start the motor drive.

2.Load your camera with slide film, ISO 100 or faster, or print film, ISO 400 or faster!

3.Set the f/ratio of your camera lens so that it is a half stop to one full stop down from completely open.

4.Set the shutter speed to the “B” setting and focus the lens to the infinity setting.

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.