Changing background values on STi images. Causing guiding problems and star fades.

Hi Owen, I finally got a clear night, having the "Auto-Expose After Filter Change" unchecked has made no difference, I am still getting the bad images with the STi.

Any other suggestions?

Thanks.

 

Hi Joshua,

I'd like to rule out interactions with the main camera as the cause of the guider image problem. Can you please do some autoguiding with "Record Tracking Images" turned on (Guide tab | Options menu), and just let it run without taking any main camera exposures? Let it go at least as long as it usually takes for the problem to have occurred a few times under your usual operating conditions. (We record the images just to be sure we don't miss anything. ) Open the FITS Header Viewer and watch the track index value, which counts up with the guider exposurse.

If it seems to work okay, without stopping guiding, take note of the index and launch a simple sequence of main camera Light exposures with no filter changes. Keep tracking, exposing, and recording tracking images until the problem appears. Shut down everything gracefully, package up the recorded images along with the MaxIm DL log and upload it here so I can take a look.

The point of this exercise is to see if we can control the problem by avoiding or triggering main camera exposures. If it still occurs with guiding alone that vastly localizes the problem.

- Owen -

 

Hi Owen, I will be happy to do this no problem, however I can tell you the series of images I posted when I started this thread were taken with only the guide camera active, and I'm pretty sure I have also tested without my main camera even connected to the PC.

 

If you're 100% sure then don't want to waste your time. I've been basing all my suggestions on the theory that there's an invalid interaction between the two cameras. If that absolutely cannot be the case then I'll have to consider another approach.

Can you try guiding with the main camera, and your guide camera disconnected? You can create a new File | Configuration and don't even define Camera 2; throw the configuration away when finished testing. If the problem appears in this configuration too, then we can rule out hardware failure as the culprit with a high degree of certainty.

- Owen -

 

I can do that no problem, will depend on the weather of course.

Do you want me to save any of these images while guiding with the main camera? BTW the main camera is an ST-8300M.

Also in case this information is useful remember that I never had this problem with my Orion SSAG camera with all other variables the same.

 

I'm mostly interested in the overall result ("Does this configuration fail or not?"), but please do record the tracking images. You never know if one of them will contain the clue we need if it does fail. Clearly I'm in the "better too much data than too little" camp.

Thanks.

- Owen -

 

Hi Owen, just wanted to let you know it might be a little while until I can test this, it seems my PC at the observatory died.

Maybe someone else that is having this problem can test so we can keep the ball rolling on this and get it fixed???

Thanks, Josh

 

Just wanted to confirm that the STi camera still has the problem even if it is the only camera connected to the PC.

Any progress on this problem?

 

Hi Josh,

There is one recent development that you should try if you haven't already. You need V6.17 installed, and this patch. Getting it and the latest driver from DriverChecker64 will at least bring you completely up to date.

- Owen -

 

I'll be happy to record all the images you like, but if you look at the start of this post I did upload quite a few. But I will gladly do more if you want. I'm at the point I'm about ready to send you my entire hardware setup so you can figure it out.

No I'm running 6.16, my upgrade subscription has expired. If I know that it will fix my problem I would be willing to upgrade, however I just have a problem with paying for a fix that in software that should have been working properly in the first place. I have no problem what so ever paying for new features. Not trying to be a complainer, just my personal thought on the matter.

I guess I can download a demo then install the patch and see if that works?

 

Thanks. We are past full moon and approaching new moon so our stretch of cloudy skies coming in is right on schedule. I will probably wait until it looks like we will get a clear night to install the demo. I'm pretty sure I've never had a demo on that PC.

 

Hi,
I think I am also having this problem. It has been going on for sometime, but recently has picked up dramatically in frequency. I can no longer acquire guided images, the system stops after a few minutes.

I am using ACP/Maxim 6.06 with an SBig STF8300M with OAG/Sti and 8 position filter wheel. I came across this thread while trying to find what I should do to try and diagnose the problem. When ACP is picking a guide star the SNR for the selected star varies quite a bit, causing ACP to keep trying different stars.

If a guide star is finally selected the image in the tracking box frequently goes black, where all the pixels have gone to zero. There will be a small star in the center, looks like a hot pixel. This typically generates the Star faded message.

The only thing that has changed recently is that the temperature here in Az has risen a bit. At night it is 85-90 while imaging. The hot weather will be coming in soon, where it will be 100+ through the night. Perhaps there is a flaky temperature dependence in the hardware.

Anyway, it certainly sounds like Joshua has provided a lot of data. I am getting ready to run the DriverChecker to ensure the drivers are updated. If I can provide data or testing I am available. I will certainly be interested in whatever fix is developed.

Robert Brewington

 

Mine certainly has this problem more frequently the warmer the temperature.

 

Josh – Thank you for pointing me to this thread. I too have been battling the identical symptoms on an STT-8300M/FW8G-STT, and it’s good to know that I am not alone!

I’ve uploaded a 25-second video taken with my cell phone showing 11 guide frames in succession with the system running. The guide star disappears in frames 5 and 9. Please let me know if this is the symptom you experience as well:

I’ve spent a year isolating the problem, and can share any data and insights. First, what the problem is not. I have swapped hardware and software at every stage of the process as follows:

· Power: I’ve used 3 different AC power supplies (one SBIG, the others aftermarket, all 12V 6A 72W). I’ve swapped all power cables, and even the AC wall plug outlets. No difference.
· Cables: I’ve swapped the HDMI cable between FW and camera, the 6-pin reversed RJ11 between camera and mount, and the USB cable between camera and laptop. No difference.
· Computers: I’ve swapped laptops, operating systems, and USB ports. No difference.
· Software: I use CCDSoft 5 because I have it, it’s simple, and it works. Others have used CCDOps, Maxim DL 5 & 6.x, TheSky X, and PHD on various PCs. No difference.
· Settings: Binning 2x2 or 3x3 makes no difference. Auto-Dark and auto-contrast settings make no difference. Exposure length makes no difference (a clue).
· Downloading: The problem is independent of main camera image acquisition, USB downloading, or filter changes.
· Cooling: The problem is independent of power draw for TE cooling or fans.
· Mechanical: The mechanical shutter in the FW8G-STT remains open as expected during guiding operation, and shows no anomalies. This is an electronic shutter problem.
· Other: There are no other issues or anomalies in camera/filter/mount operation. Imaging is fine so long as a bright guide star is available. (Any other problems are squarely the fault of the astronomer…)
· Drivers: SBIGUDrv.DLL Ver 4.99 Build 3 sbigu64.sys Ver 2.41.0.1338
· Firmware: Version 2.58, Serial Number T13050394

This leaves one thing we all have in common: both the FW8G-STT and the STi use the same On Semi KAI-0340 chip, and I assume SBIG powers and reads this sensor with the same on-camera electronics. A couple of additional observations:

(1): When I first start guiding, I can go 30 to 50 frames before I get a bad one. Very soon afterward it drops to one in 10, then one in 5. Later in the night I can get 3 or 4 bad frames in a row. (Bad frames are identical, and distribution in any short time frame is random.) The problem sure looks like a component overheating somewhere.

(2) Bad images are not a function of exposure length. Short or long, each bad image looks like it was dumped prematurely after a set amount of acquisition time, much shorter than commanded. Bright stars shine through this; dim ones do not, no matter what the exposure.

Doug, Adam, Owen, and Bill, we need help here…

Thanks,
Tony

 

You cannot imagine how happy I am to see this data. I have suffered with this for years now. Last night I had more than usual due to the heat I think....

In any case, this has led me down the rabbit hole of using multi-star guiding because when you use single star and you get those bogus frames they may be read as a number like 30 for the offset and then your mount corrects and basic the sub is a throwaway.... for some reason multi-star ignores this.

BUT, multi-star has a fault whereas it does not play well with ACP/Expert scheduler and hangs the system....

I just paid for another year of support... how about prioritizing fixing multi-star since if the frame is a hardware issue, at least this is a workaround.

You can see my thread on this problem somewhere.... nobody has commented as far as I can see:

http://forum.diffractionlimited.com/threads/acp-maxim-error-on-multi-star-guiding.4736/

Bob Denny is aware of the problem.

 

Yea the video you posted is exactly what I see.

I'm confident this is a hardware problem, not software, because it gets worse the warmer the ambient temp. Almost seems like a design problem with this chip and nobody seems to want to admit it.

 

I’ve pretty much thrown in the towel on my SBIG STT guider. The only solution I’ve got is to run a guide star with saturated pixels and try to drown out the bad subs. But for the most part I’ve beem using a CMOS and going unguided with my MYT. How long can you wait for a solution?

 

Guiding right now on a marginal star. Horrible dropout/fade problems with the guide images - one third are bad. At 2x2 binning, the guider jerks and bumps like a bronco with each fade. At 3x3 binning it is relatively stable - just enough of the star image comes through to establish a proper centroid on the bad images. Same exposure time in both states.