Jul 13, 2016 UT: Tests of Atik camera, filterwheel, off-axis guider

Michael Richmond
Jul 15, 2016

On the night of Jul 12/13, 2016, I tested our "new" imaging equipment.

The main setup was:

• Meade 12-inch telescope
• no focal reducer, so working at f/10
• ATIK 11000 CCD camera with Atik EFW-2 filterwheel
• images binned 2x2, so 1.32 arcsec/pixel
• ATIK off-axis guider with Orion G3 Starshoot Monochrome camera
• new focuser

Notes from the night

• sky was hazy, temperatures very warm
• filterwheel had
  1. empty, called "Red" by MaximDL
  2. B, called "Green"
  3. V, called "Blue"
  4. R, called "Luminance"
  5. I, called "5"
• I had to unplug and replug the power to the filterwheel once, but after that, it did respond properly to MaximDL
• focus position in V: 0.422 inches

The orientation of the camera and filterwheel and off-axis guider was as follows:

The guide camera should be screwed into the off-axis guider with none of its three spacer rings; when mounted on the scope, it looks like this as seen from the back:

With this orientation, I needed to change the settings in MaximDL so that images would appear on the screen in the standard "North up, East left" format. In the "Camera -> Setup -> Options -> Settings" menu, I changed

• orientation from "rot 90 CW" to "no rotation"
• "flip horizontal" from "checked yes" to "not checked"
• "flip vertical" from "checked yes" to "not checked"

I also needed to change the settings of the off-axis guide camera so that IT would have the proper orientation:

• orientation from "rot 90 CW" to "no rotation"
• "flip horizontal" leave as "not checked"
• "flip vertical" from "not checked" to "checked yes"

Next, I tried to figure out where the field of the off-axis guider lay, relative to the field of the main CCD. I used the Moon as my target. Here's a cropped image of the Moon in the main CCD; pay attention to the boxed region.

When I move the Moon to the western edge of the main CCD's field, we can see the shadow cast by the pick-off mirror of the off-axis guider:

I took images simultaneously through the main CCD and through the guide camera. With a little work, I was able to figure out the location of the guide camera's field. Note that the guide camera is rotated by about 30 degrees relative to the main camera:

So, the pick-off mirror will send light from objects at the western edge of the main frame to the guide camera.

I saved the MaximDL settings in the configuration file mwr_atik_efw_guider_jul2016.

Last modified 07/15/2016 by MWR.