Hi all, I've got an ST-2000XCM which I have been using for a few years now without a problem, but I recently started noticing intermittent horizontal banding appearing in images. It seems more frequent and severe in exposures that are less than about 60 seconds (where it happens in about half the images), but I have occasionally seen it in longer exposures as well. I'm currently using CCDSoft version 5 for image acquisition. Here is an example 3 second exposure, binned 2x2 (though it occurs at 1x1 binning as well): http://h.dropcanvas.com/hm6ef/Bandingexample.tif Raw FIT file here as well: http://dropcanvas.com/hm6ef The telescope is an 8" LX200 Classic at f/6.3 and the autoguider seems to still be working fine. I haven't noticed any banding in the autoguide chip, but due to subsampling during guiding I may just not be seeing it. I recently started using a new Windows 10 laptop so I don't know if that may somehow be contributing to the problem. It does seem to occur regardless of whether I'm running off of batteries and a power inverter out in the field, or off a wall outlet at home (as was the case in the example posted above). It hasn't stopped the camera from producing fine images when stacking long exposures, but I'm concerned something may be starting to go wrong. I wanted to know if this is just some kind of issue caused by the new computer and drivers, or is this a sign of impending hardware failure (and if so, can anything be done to stop it/fix it)?
Nothing I can think of. I had to re-download CCDSoft and the SBIG drivers for the new PC, but they seem to be working fine except for this.
Curious. We've tested the current drivers (actually a new release will be out probably tomorrow) with an ST-2000XME with no problems. Try running the camera with CCDOPS. Also do you still have the old PC? Could try it with that just for comparison's sake.
Unfortunately the old PC is no longer functional. I'll try it with CCDOPS when I get a chance, though I haven't used that before and I'm not even sure if I still have the disc for it.
it looks like something that was called "Windows interrupt". It was caused by bouncing around in Windows while the image is being downloaded.
Right, I could see that happening if the readout pauses. These old cameras don't have a frame buffer; they can only store a few lines in memory. During a pause more dark current accumulates. Could explain the artifacts. What kind of computer are you using (processor, memory, etc.), and what operating system?
