Polaroid ST-8E, ST-9E Advanced Imaging Techniques, Lunar and Planetary Imaging, Deep Sky Imaging

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Section 5 - Advanced Imaging Techniques

5.Advanced Imaging Techniques

With practice, you will certainly develop methods of your own to get the most from your CCD camera. In this section we offer some suggestions to save you time getting started in each of the different areas outlined below, but these suggestions are by no means exhaustive.

5.1.Lunar and Planetary Imaging

When imaging the moon using most focal lengths available in astronomical telescopes, you will note that the moon's image typically fills the CCD. The image is also very bright. The best way to image the moon is to use neutral density filters to attenuate the light.

You may also try an aperture mask to reduce the incoming light. If you feel that an aperture mask reduces resolution to an unacceptable degree, consider using a full aperture solar filter. This will result in an optimum exposure of only a few seconds. Another way to reduce the incoming light is to increase the effective focal length of your telescope by using a barlow lens or eyepiece projection. This is very desirable for planetary imaging since it also increases the image size.

5.2.Deep Sky Imaging

Ordinarily, with telescopes of 8" aperture or larger, a ten second exposure in focus mode, with a dark frame subtracted, will show most common deep sky objects except for the very faintest. This is a good starting point for finding and centering deep sky objects. If you find ten seconds to be insufficient, a one minute exposure will clearly show nearly any object you wish to image, particularly if 2x2 or 3x3 binning is selected. Using the Grab command, exposures of five minutes will generally give you a clear image with good detail. Of course, longer exposures are possible and desirable, depending on your telescope's tracking ability or your desire to guide. Once you have determined the longest exposure possible with your particular drive error, try Track and Accumulate exposures of a duration less than your measurable error. We have found that exposures of thirty seconds to two minutes are best depending on the focal length of telescope one is using. With the self guiding feature of the ST-7e/8E/9E one can take long integrations while the internal tracking CCD guides the telescope.

We highly recommend that you initially pursue deep sky imaging with a fast telescope, or focal reducer to produce a final F number of F/6.3 or faster at the CCD. The sensitivity advantage is considerable!

5.3.Terrestrial Imaging

An optional accessory for the SBIG cameras is the camera lens adapter. These accessories are made to accommodate most popular camera models. You may attach a camera lens in place of your telescope and use the CCD camera for very wide angle images of the night sky or for terrestrial views in daylight. Begin with a tenth second exposure at f/16 for scenes at normal room light and adjust as necessary for your conditions.

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Contents Operating Manual Page Table of Contents Technique Road Map of the Documentation IntroductionQuick Tour Ccdops for Windows or Macintosh Ccdops SoftwareCCD Camera Page Cameras in General Introduction to CCD CamerasHow CCD Detectors Work Camera Hardware Architecture Full Frame and Frame Transfer CCDsCCD System Block Diagram Cooling CCD Special RequirementsDark Frames Double Correlated Sampling ReadoutPixels vs. Film Grains Flat Field ImagesGuiding Electronic Imaging Black and White vs. Color Page Step by Step with a CCD Camera At the Telescope with a CCD CameraAttaching the Camera to the Telescope Establishing a Communications Link Focusing the CCD CameraCamera Back Focus Taking an Image Finding and Centering the ObjectDisplaying the Image Processing the ImageAdvanced Capabilities Crosshairs Mode Photometry and AstrometrySub-Frame Readout in Focus Autoguiding and Self Guiding Track and AccumulateColor Imaging Auto GrabAt the Telescope with a CCD Camera Connecting to the Computer Connecting the PowerConnecting the Relay Port to the Telescope Camera HardwareUsing Mechanical Relays Push to Make Switch Modification Joystick Modification Modular Family of CCD CamerasSystem Features 20.6x sizeum Focal length cm Camera Hardware Connecting the older model CFW-6 filter wheel to the Camera Battery Operation Page Lunar and Planetary Imaging Advanced Imaging TechniquesDeep Sky Imaging Terrestrial ImagingTaking a Good Flat Field Changing the Camera ResolutionBuilding a Library of Dark Frames Flat Fielding Track and Accumulate Images Tracking Functions Advanced Imaging Techniques Page Cooling Booster Accessories for your CCD CameraCamera Lens Adapters and Eyepiece Projection Tri-color ImagingFocal Reducers AO-7 and Lucy-Richardson SoftwareSGS Self-Guided Spectrograph Third Party Products and ServicesWindows Software Image Processing SoftwareSbig Technical Support Common Problems Common Problems Common Problems Page Glossary STV Glossary Glossary Appendix a Connector Pinouts Appendix a Connector ad CablesSbig Tracking Interface Cable TIC-78 Figure A1 CCD Connector for TIC Mating Cleaning the CCD and the Window Appendix C MaintenanceRegenerating the Desiccant Page Technique Appendix C Capturing a Good Flat FieldPage Index IBM PC Separations
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