Random noise being added to guide exposures (and more)

I'm using an STT8300 with the self-guiding filter wheel and AO. I'm getting weird extra signal/noise added to my guide cam exposures every few minutes. Normal and problematic examples are attached. In the bad one, the guide star is still there but extra noise signal is being added. At first I thought is was just unlucky clouds but this is something that randomly afflicts individual exposures - the one before and the one after always look perfectly normal.

This is a debilitating problem because the guide program (TSX in this case) reads the noise as a new star location and moves the AO way off. So I end up with little stars next to the real star on my main cam subs.

I believe I may be having a similar/related problem with main camera too. I noticed that I had frequent fails with FocusMax4 and watched a few focus runs. I would see the focus star picked up nicely but at some point in the run the star would just disappear. Possibly this is that same added signal sometimes washing out the focus image.

I had not seen any issues with main camera object images but last night after 3 solid images I saw the image signal drop way down even though there were no clouds in the sky. My plate solves were failing then also due to limited star signal. Looking at the images it seems as though there is just less signal, not the added noise signal I see on the guider images.

Is there anything I should look at before sending everything to Bill?

Thanks,

Kevin Morefield

 

Just curious but is what your seeing similar to what I'm getting with my STi? See this thread.

http://forum.diffractionlimited.com...causing-guiding-problems-and-star-fades.3344/

 

Yes, same thing it sounds like. I put a link to this thread on yours.

 

Hi Kevin.

I just wanted to chime in and let you know that I have experience this same issue for quite a while and with both my STT-8300's.

Here is a link to a thread I started quite a while back.

http://forum.diffractionlimited.com/threads/periodically-noisy-guide-images.785/

It looks like SBIG might have some insight into the problem based on this post from October

http://forum.diffractionlimited.com/threads/periodically-noisy-guider-images-with-stt-8300m.2766/

However, since you are using TSX and having the same problem, it would be good if someone from SBIG can confirm if this is an issue that will be fixed on the firmware or driver side.

Sam

 

Sam, the forum says I don't have access to see your post - is it still up?

Thanks,

Kevin