I've got an AllSky camera that is about a year old and it's doing something I've never seen before; it's as if the gain is too high. During the day when you start to capture frames the first frame looks normal, e.g. there are columns of saturated pixels about the width of the Sun, however subsequent frames are severely over exposed. Nighttime operation seems normal. The attached frames are the 1st and 2nd frames in the series. The exposure time for both of the attached frames was the same: EXPTIME = +0.000000000000E+000 Any ideas what might be causing this? Thanks, Nick
This seems to indicate a '0' second exposure. Are you using the AllSky software from our website? Can you confirm what you have the exposure time set to?
Tim, I'm using the software that shipped with the camera on CD. I can try reinstalling with the software from the website, but this camera worked fine with the supplied software on CD until now. Something has changed and I'm not even sure if it's hardware of software. I am using the default maximum exposure setting of 2 minutes and there is no minimum exposure setting (at least not from the GUI). The '0' second exposure is what is reported in the fits header from a single frame. I'll try reinstalling the software from your website. Nick
Tim, I uninstalled the software and installed Version 1.0.37.0 from the SBIG website and I'm still getting the same results. It's overcast here and about a third of the frame is completely saturated. Any other ideas? I'm beginning to think this is a hardware issue. Nick
Looks like this is a hardware issue. I installed the software on a different laptop and used a different RS-232 cable and got the exact same results. I even flashed the firmware (new file was the same version). Any other ideas before I send this off to Bill? Nick
Have you checked there's nothing on or stuck under the optics, in front of the sensor? (Just thinking about unlikely possibilities).
The dome is almost spotless, but I went ahead and removed it to check the lens and all the glass is pristine. I also held open the shutter with a toothpick and the CCD itself is clean. I can't make sense of this; why would the first frame in a series be good, and subsequent frames be overexposed?
Odd indeed. Maybe the shutter is slow to open on the first image, or not closing properly on subsequent ones? Speculating won't help I guess, sounds like repair time.
