Hi , since a few weeks my st-i experimented a new issue. I always have had the time out issue but somewhat rare and not blocking for me. now I have something different. sometimes, during guiding, the guide star is completely lost. At the beginning I thought at clouds but then realized it is the camera. It can be a frame, a series , or a frame every 20 minutes. the problem is that it ruins my exposures. I don't know if it is a readout problem or a shutter problem, but I start suspecting the shutter: I usually autodark my guide frames and i can see hot pixels appearing on the empty frame. sometimes the frame is divided in two part by an horizontal line. the camera is connected to a powered HUB Moxa (certified industrial) I use skyx camera add on at present. can you help nme to debug the problem? thanks a lot, Andrea
See my post here, http://forum.diffractionlimited.com...causing-guiding-problems-and-star-fades.3344/ Is my problem similar to what you are seeing?
Hi Joshua, I am not sure but it seems different. In your images I can see the remnants of the two stars: I need to check stretching my defective frames but I would say there are no stars in mine. my frames are completely black with some hot pixels. I usually expose from 5 to 10 seconds to get a target of 8000 adu on the guide star, autodark subtraction. therefore, the star is not a faint one. thank you, Andrea
My problem is the background noise raises at random intervals and if the star isn't bright enough gets lost in the noise.
One blank guide frame should not affect your exposure. Autoguiding works because of the continuous corrections; if you miss one the next one will pick up the slack. That said, we will look into whether there is an issue with dropping frames.
Hi Doug, thank you. When it happens, there is a big spike on the guiding graph and a big correction is triggered. (only limited by max move) In the bad guiding frame I can see bright pixels, so it is like if one of these is selected for the guiding (just an hypotesis). You are right, with a star fading the guiding cycle is not executed. and can confirm that this is not a problem for me. I am attaching a few frames: it is rainy here so they are just captures inside the observatory. these are full frames and don't know if what I see on the guide box is the same problem. I can send something more when it clears. Thanks a lot, Andrea
That's definitely not normal. Please use the SBIG Driver Checker to update all your drivers. Try running the camera from CCDOPS and see if you get the same problem.
Thank you Doug, I need to install CCDOPS this evening and let you know. For the time being I tried with Maxim 6.08 and got a very similar behaviour (I am eligible till 6.11 if this matter) Andrea
