To remove fixed pattern noise, SKG allows to subtract a dark frame from the guider frame.
With a cooled camera it may also remove hot pixels, however we recommend to use the median filter instead for hot pixel removal.
Check if your guider camera has a shutter prior capturing a dark frame. If there is no shutter, you will have to cover the scope before taking the dark frame and uncover it once the dark frame has been captured.
To capture a dark frame, you must click on the button.
Dark frame is disabled when instrument is not connected and when exposing is started.
Once the dark frame has been successfully captured, it is automatically saved in the working folder and the following message box is displayed:
The dark frame is a single frame without any processing. If you want you can use a master dark instead of the single dark frame captured by SKG.
To do that you must observe the following consideration:
1. The binning of the master dark must be the same as the binning configured for the guider camera.
2. The resolution of the master dark must be the same as the single dark frame.
3. The file name of the master dark must be the same as the single dark frame.
4. When master dark overwrite the single dark, you must restart SKG to load the master dark instead from the working folder.
The check box at left side of the button allow to enable/disable the dark frame subtraction after each guider camera exposure.