My STi cameras started giving images as shown below. There's a weird "herring bone" pattern in the middle half of the image. I swapped USB cables, swapped computers, long exposure, short exposure, Bin 1, Bin 2 all the same and gave up. It almost looks like the anti-blooming feature isn't working in the distorted part of the image. Any suggestions? (I already emailed Bill) Larry lobo59@me.com
Hi Larry, can you post a 1x1 FITS light image, bias, and dark ? We can't do anything with a JPG. Also, what's the optical configuration - eg is it in an OAG-8300 or some other off-axis gizmo, or in a guide scope, etc. Did you visually inspect it for contamination on the optical window?
"Weird" is right! Will definitely want to see FITS frames for this one. Some thoughts based on the JPEG images: I can see a loss of charge transfer efficiency vertically in the distorted area, in addition to the horizontal lines - hot pixels are streaking vertically. That implies that the CCD clock voltages are unstable. My best guess is that an internal power supply regulator has failed. The voltage could be bouncing up and down as the vertical and horizontal clocks start and stop, resulting in out-of-spec clocks and producing that pattern.
Here are Light, Dark and Bias FITS frames at 3 second exposures for the Light and Dark taken with a cover on the camera, ie not installed on a telescope. I first noticed the issue when the camera was installed in a OAG-8300 attached to a STF-8300. The results were the same as these new frames. The frames taken with the STi installed on the camera are on the computer at my remote observatory. I'll try to download those later in case you need them. Also I confirmed that the drivers and firmware are up to date. Larry PS I was able to download the images taken with the camera on the scope and have added them to this post including one with a dark subtracted from the light.
Looks like your camera needs to go in for service. Please contact Bill @ SBIG Service & Repair, bill@sbig.com
Hi Larry, the camera definitely has an electronics failure as Doug outlines. I suggest you get this in to @Bill for repair.
