Take a sub array image
This is an experimental feature.
A sub array image can be used to take images of double stars or other bright objects.
The principle is similar to a frame transfer CCD
The shutter is opened, after about 30 ms the lines of the CCD are shifted in the direction of the readout
register(that lines are dumped), then the next sub array is exposed and so on until the CCD is filled
Then the image is transferred to the computer
Example: ST-7, Tracking CCD, Height Sub array 10:
You get the object 16 times on the frame.
The tracking of the telescope is on.
Place the object you want to expose, near the bottom of a standard image
( That is opposite to the readout register).
There should not be any other bright objects at the same columns.
Chose Camera - Settings
Declination, Focal Length, Sidereal Rate no entries required for this kind of imaging.
CCD - imaging CCD or tracking CCD, using the tracking CCD the
time to shift the lines is shorter, so there should be less streaking in the image.
Binning - 1 x 1 binning in most cases to get a high resolution, other binning modes
may be also possible.
Planetary mode - It is not necessary to use the planetary mode (the time to dump the lines
will not decrease in using planetary mode)
Focus (check Box) - not checked
Light or dark frame - light frame
Auto Grab number of images - 1 or more
Brake during taking an image - enabled
At the bottom of the form at the left, there is a Page Control
Chose the Sub Array Tab Sheet
Exposure Time per Sub Array - should be about 0.03 s
Height Sub Array - depends on the size of the object , about 10 for double stars.
After checking all entries, leave this form.
Then chose: Camera - Take Sub Array image.
It is asked for the file name and the exposure is started.