Polaroid ST-7E, ST-8E, ST-9E manual Common Problems

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Section 7 - Common Problems

following suggestions.

The easiest method of finding objects is to use a reticule eyepiece, if the object is bright enough to see. Pull the CCD optical head from the eyepiece holder and insert a 12-20mm eyepiece, focussing the eyepiece by sliding it in and out of the eyepiece holder, not by adjusting the telescope's focus mechanism. Center the object carefully (to within 10% of the total field) and then replace the CCD optical head. Since the head was fully seated against the eyepiece holder when you started, fully seating it upon replacement will assure the same focus.

If the object is too dim to see visually you will have to rely on your setting circles. Go to a nearby star or object that is easily visible and center that object in the CCD image. Calibrate your RA setting circle on the known object's RA and note any DEC errors. Reposition the telescope at the intended object, using the correct RA setting and the same DEC offset noted with the calibration object. Try a ten second or one minute exposure and hopefully you will have winged the object. If not you will have to hunt around for the object. You can use the Focus mode in Low resolution mode for this and hopefully you won't have to search too far. Check in DEC first, as DEC setting circles are often smaller and less accurate.

Telescope Port doesn't Move Telescope - If you find the camera is not moving the telescope for Tracking, Track and Accumulate or Self Guiding you should use the Move Telescope command with a several second period to isolate the problem down to a specific direction or directions. If you set the Camera Resolution to the Low mode in the Camera Setup Command, you can move the telescope and Grab an image fairly quickly to detect movement of the telescope pointed at a moderately bright star. Try each of the four directions and see which ones move and which ones don't. At this point the most likely culprit is the hand controller modification. Trace the signals from the camera's telescope connector back through the hand controller, paying particular attention to the offending wires.

Can't Reach Low Setpoint Temperatures - If you find that the camera isn't getting as cold as expected the problem is probably increased ambient temperatures. While these cameras have temperature regulation, they still can only cool a fixed amount below the ambient temperature (30 to 40 °C). Lowering the ambient temperature allows the cameras to achieve lower setpoint temperatures.

CCD Frosts - If your camera starts to frost after a year of use it's time to regenerate the desiccant as described in Appendix C. This is a simple matter of unscrewing the desiccant container and baking it (without the little O-ring) in an oven at 350°F for 4 hours.

No Image is Displayed - Try the Auto Contrast setting or use the crosshairs to examine the image pixel values and pick appropriate values for the Background and Range parameters.

Horizontal Faint Light Streaks in Image - some PCs apparently have the mouse generate non- maskable interrupts when moved. These interrupts can slightly brighten the line being read out. If this occurs, do not move the mouse during read out.

A/D Timeout or Other Errors - Some compters require that you configure the parallel port for "Standard" mode instead of "ECP" or "EPP" mode. These two enhanced modes can

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Contents Operating Manual Page Table of Contents Technique Introduction Road Map of the DocumentationQuick Tour Ccdops Software Ccdops for Windows or MacintoshCCD Camera Page Introduction to CCD Cameras Cameras in GeneralHow CCD Detectors Work Full Frame and Frame Transfer CCDs Camera Hardware ArchitectureCCD System Block Diagram CCD Special Requirements CoolingDouble Correlated Sampling Readout Dark FramesFlat Field Images Pixels vs. Film GrainsGuiding 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 Focusing the CCD Camera Establishing a Communications LinkCamera Back Focus Finding and Centering the Object Taking an ImageDisplaying the Image Processing the ImageCrosshairs Mode Photometry and Astrometry Advanced CapabilitiesSub-Frame Readout in Focus Track and Accumulate Autoguiding and Self GuidingAuto Grab Color ImagingAt the Telescope with a CCD Camera Connecting the Power Connecting to the ComputerConnecting the Relay Port to the Telescope Camera HardwareUsing Mechanical Relays Push to Make Switch Modification Modular Family of CCD Cameras Joystick ModificationSystem Features 20.6x sizeum Focal length cm Camera Hardware Connecting the older model CFW-6 filter wheel to the Camera Battery Operation Page Advanced Imaging Techniques Lunar and Planetary ImagingDeep Sky Imaging Terrestrial 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 Accessories for your CCD Camera Cooling BoosterTri-color Imaging Camera Lens Adapters and Eyepiece ProjectionFocal Reducers AO-7 and Lucy-Richardson SoftwareThird Party Products and Services SGS Self-Guided SpectrographWindows Software Image Processing 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 Appendix C Capturing a Good Flat Field TechniquePage Index IBM PC Separations
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