request to detect and report absence of stars and/or overall image brightness level

[GoogleCodeExporter]

I have had a problem with my SBIG STT-8300M camera with the built-in guide 
camera.  As I reported in

https://groups.yahoo.com/neo/groups/SBIG/conversations/messages/257084

The cable from the guide head to the camera body can come disconnected.  In 
this case PHD2 seems to receive an image that is almost all black, but with 
some noise.  When looking at this image in PHD2, it is not noticeably different 
from a valid image that does not show any stars, perhaps because it is not yet 
dark, or the focus is far off. 

The camera interface does not return any errors, and it took me a long time to 
determine that something was wrong with the camera.  It would be nice if PHD2 
could notify the user of the lack of significant image.  Even when I increased 
the exposure time, I could not see any difference.  I could not tell that the 
image was actually dark as there is not any information of the overall 
brightness.  This is hidden by the processing that accentuates the stars.  
While this is great normally, it hides this abnormal condition.  I only 
realized the problem when I shifted to another program that displayed the raw 
image and enabled a histogram which showed all dark.

Fred Klein

Original issue reported on code.google.com by andy.gal...@gmail.com on 16 Jul 2014 at 5:44

[GoogleCodeExporter]

Fred,

Could you please provide a sample image of what the camera produces when the 
guide head cable is disconnected?  You can attach the fits file (use File => 
Save Image in phd2) to this issue report.

Thanks,
Andy

Original comment by andy.gal...@gmail.com on 16 Jul 2014 at 5:51

• Changed title: request to detect and report absence of stars and/or overall image brightness level

[GoogleCodeExporter]

Here are two images, one with the cable connected and the cap on the camera and 
the other with the cable disconnected.  Both were with PHD2 directly connected 
to the SBIG camera driver from PHD2.

Original comment by kle...@gmail.com on 16 Jul 2014 at 6:48

Attachments:

• Guide-w-cable.fit
• Guide-wo-cable.fit

[GoogleCodeExporter]

Original comment by andy.gal...@gmail.com on 16 Jul 2014 at 8:44

• Changed state: Accepted