Celestron C8-NGT, C10-N manual Terrestrial Photography, Metering, Reducing Vibration

Page 42

Lunar Phase

ISO 50

ISO 100

ISO 200

ISO 400

Crescent

1/2

1/4

1/8

1/15

Quarter

1/15

1/30

1/60

1/125

Full

1/30

1/60

1/125

1/250

Table 7-1

Above is a listing of recommended exposure times when photographing the Moon at the

prime focus of your telescope.

The exposure times listed in table 7-1 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 will get a good photo.

•If using black and white film, try a yellow filter to reduce the light intensity and to increase contrast.

•Keep accurate records of your exposures. This information is useful if you want to repeat your results or if you want to submit some of your photos to various astronomy magazines for possible publication!

•This technique is also used for photographing the Sun with the proper solar filter.

Terrestrial Photography

Your telescope makes an excellent telephoto lens for terrestrial (land) photography. Terrestrial photography is best done will the telescope tracking drive turned off. To turn the tracking drive off, press the MENU (9) button on the hand control and scroll down to the Tracking Mode sub menu. Use the Up and Down scroll keys (10) to select the Off option and press ENTER. This will turn the tracking motors off, so that objects will remain in your camera's field of view.

Metering

The Advanced Series telescope has a fixed aperture 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.

42

Page 41 Page 43
Image 42
Page 41 Page 43
Contents Advanced Series Advanced Series GT Precise GoTo Scope Setup Features Telescope Maintenance Page Advanced Series Newtonian Advanced Series GT Newtonian Setting up the Tripod Attaching the Equatorial MountInstalling the Counterweight Bar Attaching the Center Leg BraceInstalling the Counterweight Attaching the Hand Control Holder Advanced GT Models OnlyAttaching the Telescope Tube to the Mount Installing the Finderscope Installing the EyepiecesTelescope Balancing the Tube in R.A Telescope Tube CompletelyAdjusting the Mount Adjusting the Mount in AltitudePowering the Telescope Attaching the Declination Cable For GT Models OnlyAdvanced GT Hand Control Hand Control Operation Alignment Procedures Startup ProcedureAuto Align Auto Three-Star AlignQuick-Align Last AlignmentRe-Alignment Object Catalog Selecting an ObjectTour Mode Setup Procedures Nine available slew speedsIdentify Scope Setup Features Observing Tip Helpful Hint Utility Features Helpful Hint Advanced GT Image Orientation Focusing Aligning the FinderscopeCalculating Magnification Determining Field of View General Observing HintsCelestial Coordinate System Motion of the Stars Latitude Scales Pointing at PolarisFinding the North Celestial Pole Declination Drift Method of Polar Alignment Observing the Planets Observing the MoonLunar Observing Hints Observing the SunSeeing Conditions Solar Observing HintsObserving Deep Sky Objects TransparencyPage Piggyback Short Exposure Prime Focus Photography Terrestrial Photography MeteringReducing Vibration Auto Guiding Care and Cleaning of the Optics CollimationAligning the Secondary Mirror Aligning the Primary Mirror Night Time Star Collimating Page Page Page Page Appendix a Technical Specifications Appendix B Glossary of Terms Page Eclipsing or obscuring the brightness of the star Appendix C Longitudes Latitudes Georgia Minnesota Rhode Island Canada Appendix D RS-232 Connection Additional RS232 Commands Reset The Position Of Azm Or AltAppendix E Maps of Time Zones Page Page Page Page Page Page Page Celestron TWO Year Warranty
Related manuals
Manual 71 pages 692 b

C10-N, C8-NGT, C8-N specifications

The Celestron C8-NGT, C8-N, and C10-N telescopes represent a range of superior astronomical instruments that cater to both novice and experienced astronomers alike. Among these, the C8-NGT combines the advanced features of a computerized telescope with the simplicity of a Newtonian design. Its 8-inch aperture allows for impressive light-gathering capability, making it ideal for observing distant galaxies, star clusters, and nebulae. The GoTo mount enhances usability, enabling users to locate celestial objects effortlessly with the push of a button.

The C8-N, also featuring an 8-inch aperture, stands out with its open tube design that provides maximum airflow and minimizes thermal issues, ensuring optimal performance. The scope is designed with user-friendly adjustments and a sturdy equatorial mount, allowing for smooth tracking of celestial objects. Its high-quality optics provide sharp images and incredible clarity, making it suitable for both planetary and deep-sky observations.

On the other hand, the C10-N is the largest in this lineup, boasting a 10-inch aperture that dramatically enhances its light-gathering ability. This larger size makes the C10-N a powerhouse for serious astronomers looking to explore fainter objects and intricate details within astronomical features. Like the C8-N, it employs a Newtonian reflector design, allowing for a compact and manageable profile, while still providing stunning visuals across a range of celestial bodies.

All three telescopes incorporate Celestron's commitment to creating durable, robust, and user-friendly systems. They utilize premium quality glass and optics, which are coated to improve light transmission and provide high-contrast images. Additionally, they are designed with ease of assembly and portability in mind, catering to astronomers who enjoy observing in various locations.

The Celestron C8-NGT, C8-N, and C10-N serve as excellent options for anyone looking to deepen their astronomical pursuits, offering a blend of advanced technology, high-quality optical performance, and user-friendly features. Whether you're a beginner eager to peer into the wonders of the universe or an experienced observer at the peak of your skills, these telescopes offer a remarkable means to expand your cosmic horizons. With precision engineering and thoughtful design, Celestron continues to be a trusted name in the world of astronomy.
Top Page Image Contents