Polaroid ST-8E, ST-9E, ST-7E manual Camera Hardware, System Components, Connecting the Power

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Section 4 - Camera Hardware

4.Camera Hardware

This section describes the modular components that make up the CCD Camera System and how they fit into the observatory, with all their connections to power and other equipment.

4.1.System Components

The ST-7E, ST-8E and ST-9E CCD cameras consist of four major components: the CCD Sensors and Preamplifier, the Readout/Clocking Electronics, the Microcontroller, and the power supply. All the electronics are packaged in the optical head in these cameras with an external desktop power supply.

The CCDs, Preamplifier, and Readout Electronics are mounted in the front of the optical head. The optical head interfaces to the telescope through a 1.25 inch draw tube, sliding into the telescope's focus mechanism. The placement of the preamplifier and readout electronics close to the CCD is necessary to achieve good noise performance. The Microcontroller is housed in the rear of the Optical Head along with the interface logic to the PC and Telescope.

4.2.Connecting the Power

The desktop power supply is designed to run off wall voltage, and both domestic (110 VAC) and European (220 VAC) versions are available. In the field however, battery operation may be the most logical choice. In that case you need to use the optional 12V power supply or a 12VDC to 110 VAC power inverter.

4.3.Connecting to the Computer

The ST-7E, ST-8E and ST-9E CCD Cameras are supplied with a 15 foot cable to connect the system to the host computer. The connection is between the camera and the Host Computer's parallel LPT port. The camera will operate properly with up to 50 feet of cable to the computer. The computer's parallel port is easily identified since it is a 25 pin Female D connector.

4.4.Connecting the Relay Port to the Telescope

The ST-7E, ST-8E, and ST-9E camera systems can be used as autoguiders where the telescope's position is periodically corrected for minor variations in the RA and DEC drives. The host software functions as an autoguider in three modes: the Track mode, the Track and Accumulate mode (SBIG patented), and Self Guided mode (SBIG patented).

In the Track mode and Self Guided mode the host software corrects the telescope as often as once every 2 seconds to compensate for drift in the mount and drive system. The host software and the CCD camera operate in tandem to repeatedly take exposures of the designated guide star, calculate its position to a tenth of a pixel accuracy, and then automatically activate the telescope's controller to move the star right back to its intended position. It does this tirelessly to guide long duration astrophotographs.

In the Track and Accumulate mode the software takes a series of images and automatically co-registers and co-adds the images to remove the effects of telescope drift. Typically you would take ten 1 minute "snapshots" to produce an image that is comparable to a single 10 minute exposure except that no guiding is required. The reason no guiding is

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Contents Operating Manual Page Table of Contents Technique Introduction Road Map of the DocumentationQuick Tour Ccdops for Windows or Macintosh Ccdops SoftwareCCD Camera Page Introduction to CCD Cameras Cameras in GeneralHow 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 At the Telescope with a CCD Camera Step by Step with a CCD CameraAttaching the Camera to the Telescope Establishing a Communications Link Focusing the CCD CameraCamera Back Focus Processing the Image Finding and Centering the ObjectTaking an Image Displaying the ImageCrosshairs Mode Photometry and Astrometry Advanced CapabilitiesSub-Frame Readout in Focus Autoguiding and Self Guiding Track and AccumulateColor Imaging Auto GrabAt the Telescope with a CCD Camera Camera Hardware Connecting the PowerConnecting to the Computer Connecting the Relay Port to the TelescopeUsing 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 Terrestrial Imaging Advanced Imaging TechniquesLunar and Planetary Imaging Deep Sky ImagingChanging the Camera Resolution Taking a Good Flat FieldBuilding a Library of Dark Frames Flat Fielding Track and Accumulate Images Tracking Functions Advanced Imaging Techniques Page Cooling Booster Accessories for your CCD CameraAO-7 and Lucy-Richardson Software Tri-color ImagingCamera Lens Adapters and Eyepiece Projection Focal ReducersImage Processing Software Third Party Products and ServicesSGS Self-Guided Spectrograph Windows SoftwareSbig Technical Support Common Problems Common Problems Common Problems Page Glossary STV Glossary Glossary Appendix a Connector ad Cables Appendix a Connector PinoutsSbig Tracking Interface Cable TIC-78 Figure A1 CCD Connector for TIC Mating Appendix C Maintenance Cleaning the CCD and the WindowRegenerating the Desiccant Page Technique Appendix C Capturing a Good Flat FieldPage Index IBM PC Separations
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