Reading these instructions does not mean that you are qualified to operate this instrument! For training, email Elizabeth or call x56555.

NOTE: once the new 20" telescope operation guidelines are finalized, these instructions are likely to change to reflect changes in the scope's operation.

For open houses it is always nice to set up the computer to display a nice image. If an object is looking photographable you are always welcome to take some images as well. For those using the ccd for some more serious fun, you can save images to disk so you can do some image processing on them back at the astronomy department.

The Photometrics Camera System

Setting up the Computer
Displaying Images
Taking Images
Putting Away the Computer

Setting up the Computer

  • Roll the cart out of the closet to the 20" bay. Be very careful going through doors: cables and connectors which stick out from the cart can be easily damaged!!!
  • Hook up the 2 connections leading from the telescope to the back of the computer and the image display monitor.
  • Hook up the monitor cable leading from the north wall to the back of the TV monitor on the cart.
       This is only absolutely necessary for open houses or any other time you want to display images on the monitor in the lobby.
  • Plug the power cable in.
  • Turn on the power strip to the camera coolant cooler on the telescope. This MUST on anytime the computer is turned on.
  • Turn the computer on by turning on the power strip under the image monitor.

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Displaying Images

For open houses we will always want to display images on the computer. This is especially important when it is cloudy and there's nothing else for the public to see.

  • Turn on the camera coolant cooler, even if the telescope itself is not operating. The cooler MUST be on anytime the computer is on.
  • Be sure the cable that is attached to the south wall of the 20" bay is hooked up to the back of the TV monitor. This leads to the monitor in the observatory lobby, which also needs to be turned on.
  • Turn on the power to the computer by the main switch under the tv monitor.
  • When the C>> prompt appears, type cd images [CR] to get to the images directory.
  • Type ccd [CR] to start the camera control program. The prompt should change to *.
  • Type ! dir /w *.img [CR] to get a list of images.
  • Type dr {filename.img} [CR] to read an image.
  • Type qshow or fshow [CR] to display the image on the tv monitor.
    • You can play with the {x} {y} show command to improve image quality. {x} {y} show redisplays the image using the specified range of intensities. E.g. 300 1100 show [CR] scales the displayed intensities such that 300 is black and 1100 is white.
  • Multiple images may be loaded into memory by entering {n} ci dr {filename.img} [CR] where n is a number between 1 and 7. To display these images type {n} ci fshow (or qshow or {x} {y} show).
  • When finished, type quit [CR] to exit the program.
  • When you're at the DOS prompt, shut off the computer.
  • Turn off the camera coolant cooler.

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Taking Images

  • Set up the telescope.
  • Turn on the power strip to the camera coolant cooler. This MUST be on whenever the computer is on.
  • Turn on the power to the computer by the main switch under the TV monitor.
  • When you get the C>> prompt, type cd images to get to the images directory. All images must be kept in this directory.
    • You can then make a subdirectory of your own with the md command.
  • Type ccd to start the camera control program. The prompt should change to *.
  • Be sure to flip the mirror so that light is going to the camera and not to the eyepiece!

The Commands

  • To take an image type the following commands:
    • {x} ci this selects the image cache - x is any number between 1 and 7. Caches must be opened in sequence. Unless you specify a different cache with each image you take, the same cache will keep being written over. If you're not worried about saving an image, you donut need use this command.
    • {x} obs where x is the length you want the exposure to be in deciseconds. E.g. 10 obs = 1 second
    • fshow or qshow displays the picture
  • To save an image:
    • {x} ci to select the image cache you want (you can verify this by typing fshow to display the image).
    • dw {image.img} You must have the .img extension. You can include any PC-DOS pathname with the filename.
  • Other useful commands
    • qci tells you what cache you are in and the size of the image.
    • bias fshow takes a bias image and displays it, which can be useful to see how noisy the chip may be or if the chip has cooled down enough to flatten the bias (takes 30 - 45 minutes from turn on in the summer, shorter in winter).
  • When finished, type quit to exit the program.
  • When you're at the DOS prompt, shut off the computer.
  • Turn off the camera coolant cooler.

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Putting Away the Computer

  • After you've quit the ccd program and are at the DOS prompt, turn off the computer.
  • Turn off the power strip to the camera coolant cooler on the telescope.
  • Unplug the power cable.
  • Unhook the monitor cable for the lobby monitor.
  • Unhook the 2 plugs at the back of the computer and monitor that lead to the telescope.
  • Carefully roll the cart back into the closet and be sure the door to 1104 is locked.

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