A small problem I had with my SBIG STXL

[Paul Haese]

I thought it would be prudent to document this problem for anyone buying an SBIG STXL with integrated filter wheel and guide camera.

Over the last 6 months or so I had noticed images every now and then would present like the first image with odd looking artefacts. Allan Holmes from SBIG thought it might have been a clocking issue. The horizontal lines in this dark frame are not supposed to occur and I would see them in my darks and sometimes in lights. It had me worried that I had a lemon on my hands.

I brought this to the attention of SBIG and its representatives who were very responsive to the problem. After some testing it was requested to send the camera back to the States for assessment and repair. When the camera was tested at SBIG they could not find the problem and returned the camera.

Now something to note here. I only sent the camera head and not the filter wheel with integrated guide camera. It took about 4 weeks to be returned to me and I have had it back a few weeks now.

So a week or so ago I decided to test the camera again whilst waiting for an adapter to arrive. To my dismay I was once again getting the same problem with my darks. So I brought the camera home from the observatory and tried the camera again from home. I wanted to narrow down the causes of the problem and wanted to rule out anything at the observatory. With the artefacts appearing at home I knew that the cause was not in the dome via RF or power related possibilities.

So now I thought I would remove various cables until I found the route cause. There is a HDMI cable that connects the integrated guide camera to the main camera. It is quite thick and looks very robust. As it turned out the HDMI cable which supplied with the camera was the cause of the problem. To determine this I first took darks without the cable attached to both the camera and the guide camera. Darks were perfect. As soon as I attached the cable, the darks had artefacts again. Then I used a spare HDMI cable to determine if it was the HDMI cable or part of the main camera or the guide camera. In this instance it was the HDMI cable. The spare cable attached connected the guide camera and also did not create artefacts. The second image shows a typical dark since installing the new HDMI cable.

I don't know why the cable causes this problem, but if you see it on your STXL camera, this might be the cause. I would welcome any theories as to why the cable was causing this. Maybe the earth shield was faulty.

[MrB]

Inadequate internal screening of the twisted pairs would be my guess, therefore crosstalk between adjacent pairs.
Good work finding the problem, must be a relief!

[Paul Haese]

Yep it is a relief that this thing does not have to make a trip to the US again. More inconvenient than anything else. SBIG have been great in dealing with this issue.

[marc4darkskies]

Thanks Paul. Just ordered mine last week. :) Nice to know it was a simple fix!

Cheers, Marcus

[Bassnut]

geez Paul, you have so much trouble, Murphys law bites you hard :P

[Paul Haese]

Yes thankfully it was a simple fix Marcus. The actual camera produces good data as you have seen with the IC2944 and the Meat Hook images I did. Just surprised that such a cable would fail.




I think it is because I am good at bug hunting that I get these little issues. That is the fatalist way of looking at it I reckon. Still ironing out the chinks even now.

[PRejto]

Excellent detective work!! These sorts of issues can be so frustrating - especially when even SBIG couldn't come up with the solution. One would hope the company would be aware of various issues affecting their products but my experience in this hobby so far is that we are all unpaid beta testers!

Peter

[Paul Haese]

Just a little further. This problem has been seen by SBIG before and from another source that the cable seems to be defective. I bought a HDMI from Lindy which is 0.5m long and am using that. I will have to buy a common choke for it, but overall the performance is near perfect at this stage.

[Paul Haese]

An update on this issue.

My assessment is that this camera is defective. I have been in contact with SBIG and its representative here for quite some time. To date we have been trying to narrow down the cause of the problem but now I am at an end of bug hunting a camera that ought to work straight out of the box. I requested that the camera be replaced several weeks ago and SBIG have not done so yet. I was asked to conduct further tests which I have gone along with so as to find a cause, but as yet we cannot. Alan Holmes from SBIG thinks it might be sky light making its way into the camera from adjoining filters. That means the camera has a problem in my mind.

As you can see the camera has what is called a wave bar on the left hand side of the image. It moves erratically about on that side of the sensor and cannot be calibrated and as you can see it ruins perfectly good data.

I have included two darks showing what happens. One single sub and a stacked image. As you can see the destruction to the data is terrible.

I am totally disillusioned with this camera and really wish that QSI had its 700 series up and running. I would have bought that right from the start.

[RickS]

That sucks, Paul... Hope it is resolved promptly one way or the other.

[Paul Haese]

You can only imagine how much I am fuming about this problem. After 4 months I am quite ready for a new camera. Like a simmering volcano I am right now Rick. ;) It was easier getting a new worm gear from SB for my mount. Mind you I had to jump through a few hoops to get that replaced too.

To be far though SBIG have been responsive and trying to be helpful, I just want a camera that works though.

[Octane]

Ouch, that is nasty!

Hopefully, you get it resolved soon.

H

[RickS]

My Apogee U16M was a dud (contiguous bad columns) but to their credit it didn't take too many iterations with support to prove it and they took it back and replaced the sensor. Still took a few months with shipping and waiting for TrueSense to supply a replacement chip. I bought it secondhand so I was grateful just to get it repaired. If I'd waited another couple of days the sensor would have been out of warranty.

Hopefully you'll have a happy ending too, Paul!

Cheers,
Rick.

[Paul Haese]

Thanks guys.

Rick I am sure it will work out eventually. Now just complicate things I also get a grid pattern in some of my darks. This I think is RF or EM in my observatory (see dark frame, the thin vertical lines over the entire frame).

Some things that might be causing this are:



Computer is sitting on top of the UPS.
A couple of AC cables (one of which is the camera cable) are coiled loosely
Ethernet over power system. I have 4 units in the observatory.

Any ideas? I have seen this pattern whilst doing darks and the only things with power were the UPS, the camera, Ethernet and the IP power switches. No dew heaters were on.

I would welcome anyone's ideas here.

[RickS]

Paul,

How long are the darks? Might be worth taking some data samples in the dark and light areas to compare values. A screen stretch can exaggerate a trivial difference.

I haven't seen anything quite like that except for very short LRGB exposures on my U16M (a few seconds or so) which sometimes demonstrate similar patterns in the low SNR areas.

Cheers,
Rick.

[Paul Haese]

30 minutes Rick. Weird yep that is what I thought too.

[Bassnut]

We'll if your that desperate , get serious with diagnostics Paul.
Take the camera home, connect just the camera to pure DC, a battery.
Take a dark/dummy image and evaluate. I understand the cam alone is OK?.
Than add stuff, filter, plug pack etc, electrically and then mechanically , imaging each time until the fault appears.

[Paul Haese]

Took darks last night with no guide camera connected and the filter wheel disconnected electronically.

What I noticed was that with the guide camera HDMI cable removed the wave bar was still really obvious. Then when I electronically removed the filter wheel the problem was far less obvious but still present. So either the daughter boards are faulty or the problem lies in one of the peripherals. I have asked for a complete replacement and it looks like this is what is going to happen. With the change over of company ownership I am at the mercy of the new owners. I would expect nothing will change and warrantee will be honoured.

[stevous67]

I didn't really want to voice anything about my issues, but I'm dismayed to say I've had a much longer period of various issues with my STXL11K. Peter and SBIG have been responsive, but I'm still not really happy, doing many tests to try and eliminate issues. In the last few months the camera has developed the same vertical lines I can see in these dark frames
[perhaps difficult to see in my attachment]. I was advised by SBIG to use a CCDOPs vertical filter to pre-treat my subs. But it gets extremely complicated to work on the data as what do you do for Flats, Darks and Bias frames? Pre-treat these too? That's hell of a lot of extra work. What to do?

Steve

[Paul Haese]

Looks very similar Steve. I have insisted on a new camera and that is being delivered in the next 4-6 weeks as I understand it. That is what I have done.

[gregbradley]

I think if you persist and get a good one it'll be worth it judging by Martin's results with his.

Greg.

[Paul Haese]

This camera was working fine about 8 months ago Greg. This image (http://paulhaese.net/MeatHookGalaxyNGC2442.html) was done with it. So I know what it should do from experience.

It appears the previous owners reduced stocks so much that repair of the camera will be faster than waiting for a new camera. It starts heading back to the States tomorrow. Doug the head of Cyanogen will ensure it is working properly before it comes back.

I don't mind having the same camera, I just want it working. :)

[dvj]

I could be wrong, but I don't think Martin's STXL has been 100% trouble free. Nothing wrong with checking out the FLI Proline cameras. They don't have built in OAG, but you can add the AstroDon MOG to your image train.

I'm a big fan of FLI products and service. Note, that unlike SBIG, Apogee, they have not be sold.

[Paul Haese]

Yeah Martin had some issues with HDMI cable which was producing some RF related stuff but it has been sorted with a different HDMI cable.

Nothing wrong with FLI gear except the price. 9.3k just for the camera John in Australia, not to mention filter wheel, MOAG and I think maybe I would need to change the filters to square and after spending an absolute fortune on Astrodons (7 filters) I would not be keen to buy more.;) I take your point though. However, I think SBIG will sort this out for me.

[Paul Haese]

Update time

Well the camera has been to the US and is now headed back to me after quite a bit of time and I am assured it is fixed.

The cause of the problem from what I can gather was the A-D converter.

With the problem fixed (I have yet to test results myself but trust SBIG at their word) I can now get on with sorting little issues like flattener distance on the scope, any further tilt and guiding refinement.

I will post up a dark when I get the camera here again.

[Octane]

Hi Paul,

How long was your camera in the US for? Mine's been with SBIG 29 days now. I was thinking of waiting one month before sending a nudging email to find out if any work had been done.

H

[Paul Haese]

Hmmm about a month all up I think. From the time it left here until two days ago.

[Paul Haese]

Ok, I got the camera back today.

I did some darks to see what those looked like.

I have attached a copy of one of the darks. As you can see it looks pretty flat across the field, no high and low spots.

Fingers crossed that this problem has now been solved. I will do some more tests over the coming days.

[RickS]

Good luck, Paul!

[Paul Haese]

Looks like the repair has been a complete success. 15 subs at 30 minutes long at -30C last night and not a single blemish showing. A much happier astrophotographer now. On to the next problem.

[Paul Haese]

I would also like to add this.

SBIG in recent weeks since the take over by Cyanogen has been responsive and kept me informed.

Doug George the head of Cyanogen kept in contact with me up until Bill Lynch took over the repair. Bill provided me with updates and even tested things the way I had asked.

No offence to any of the former heads are SBIG but I got my camera repaired faster after the take over by a factor of 10 and that says to me that SBIG are serious now about keeping customers happy.

Just my opinion and thanks to SBIG for sorting the camera out.

[Peter Ward]

Having personally carried your camera up to Santa Barbara more than once, I can say that the out-going SBIG staff/founders spent a lot of time trying to nut out this intermittent and frustrating problem....but some problems simply take time to understand & then fix.

Sure SBIG have seen some changes in ownership, but I have known Doug George for a very long time. His software and hardware integrating skills are profound (Sirius Dome owners can thank yours-truly for enlisting Doug to develop their original Dome automation systems)

I am confident Cyanogen will keep SBIG at the "cutting edge" for some time to come.

[Octane]

Thanks for the feedback, Paul.

My apologies, I haven't been on here for a while. My time is being caught up in other causes.

I emailed Bill two days ago, as the camera had been with them for four weeks at that stage. It took 2 weeks to get there. So far, it's been six weeks.

Bill said that he has 3 other cameras to look at before mine, but, will get in touch with me as soon as he does get to mine.

I'm not in any real hurry at the moment, but, good to know it's getting there.

H