and not touching it. It is easier if you use two people for this process; one to release the camera shutter and one to hold the card. Here's the process for making the exposure.

7.Find and center the desired target in the viewfinder of your camera.

8.Turn the focus knob until the image is as sharp as possible.

9.Place the black card over the front of the telescope.

10.Release the shutter using a cable release.

11.Wait for the vibration caused by releasing the shutter to diminish. Also, wait for a moment of good seeing.

12.Remove the black card from in front of the telescope for the duration of the exposure (see accompanying table).

13.Replace the black card over the front of the telescope.

14.Close the camera's shutter.

Advance the film and you are ready for your next exposure. Don't forget to take photos of varying duration and keep accurate records of what you have done. Record the date, telescope, exposure duration, eyepiece, f/ratio, film, and some comments on the seeing conditions.

The following table lists exposures for eyepiece projection with a 10mm eyepiece. All exposure times are listed in seconds or fractions of a second.

Planet

ISO 50

ISO 100

ISO 200

ISO 400

Moon

4

2

1

1/2

Mercury

16

8

4

2

Venus

1/2

1/4

1/8

1/15

Mars

16

8

4

2

Jupiter

8

4

2

1

Saturn

16

8

4

2

Table 6-2

Recommended exposure time for photographing planets.

The exposure times listed here should be used as a starting point. Always make exposures that are longer and shorter than the recommended time. Also, take a few photos at each shutter speed. This will ensure that you get a good photo. It is not uncommon to go through an entire roll of 36 exposures and have only one good shot.

NOTE: Don't expect to record more detail than you can see visually in the eyepiece at the time you are photographing.

Once you have mastered the technique, experiment with different films, different focal length eyepieces, and even different filters.

Long Exposure Prime Focus Photography

This is the last form of celestial photography to be attempted after others have been mastered. It is intended primarily for deep sky objects, that is objects outside our solar system which includes star clusters, nebulae, and galaxies. While it may seem that high magnification is required for these objects, just the opposite is true. Most of these objects cover large angular areas and fit nicely into the prime focus field of your telescope. The brightness of these objects, however, requires long exposure times and, as a result, are rather difficult.

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Celestron 8i manual Long Exposure Prime Focus Photography, Planet ISO Moon Mercury Venus Mars Jupiter Saturn
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8i specifications

The Celestron 8i is a highly regarded telescope that has made a significant impact in the world of amateur astronomy, renowned for its performance, advanced features, and user-friendly design. Part of Celestron's Advanced Series, the 8i model boasts an impressive 8-inch Schmidt-Cassegrain optical system, which combines the advantages of a large aperture with a compact design. This allows enthusiasts to explore celestial objects with greater clarity, providing bright, sharp images of planets, star clusters, and nebulae.

One of the standout features of the Celestron 8i is its Fast Star capability, which allows for rapid imaging of celestial objects. Coupled with its advanced StarBright XLT coatings, this system enhances light transmission and increases contrast, resulting in a more vivid and detailed observation experience. This combination makes it an ideal choice for both novice and experienced astronomers who seek high-quality visuals of deep-sky objects.

The telescope's computer-controlled GoTo mount simplifies the process of locating and tracking celestial objects. With the push of a button, users can easily access a database containing over 40,000 astronomical objects, allowing for an effortless stargazing experience. The Celestron 8i also features an intuitive hand controller that enables users to customize their observations and seamlessly navigate the night sky.

The Celestron 8i is designed for portability, despite its robust optical performance. Weighing in at around 45 pounds, it is relatively easy to transport to different observing locations. The telescope's sturdy construction ensures stability while providing ease of setup, facilitating a hassle-free stargazing experience.

In terms of accessories, the 8i comes equipped with a 25mm eyepiece, offering a moderate magnification that is perfect for a variety of targets. Additionally, users can expand their observing capabilities with optional eyepieces, filters, and focal reducers, catering to both visual and astrophotography pursuits.

Overall, the Celestron 8i stands out as a versatile and powerful telescope that meets the needs of amateur astronomers at various skill levels. With its advanced features, superior optics, and impressive usability, the 8i offers a unique and rewarding experience under the night sky. Whether for planetary observation or deep-sky exploration, the Celestron 8i remains a top choice for astronomy enthusiasts.
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