Alas, my STXL has died again! Pretty disillusioned with this camera now, but I had started another project since NGC253 was not available to finish.
I am told a replacement camera will be about 2 months or I can have my lemon back with a repair. I can say I don't want the lemon back. It has been sent back three times now and that is the last time I want to see it. I will be putting up a review of this camera and the whole saga at some point in the future.
This is 2 hours of NGC1097 in Luminance. Another 5 hours or so and it would have been coming along nicely. By the time I get the replacement camera this object will be setting for the year, so it will have to wait until next year again.
Nice data. I agree a shame about the camera. When it works it seems to be good though. Failing gear/not working properly gear is a bane in this pursuit for sure.
How very annoying! I guess i've had my share of equipment problems also, but when one has premium expensive gear like you do i think its reasonable to expect greater reliability. Having to diagnose faults in a remote setup would add to the frustration (for me at least) but at least it's normally a nice drive from Adelaide down to to the south coast...
My two remaining issues is that the main chip has very noticeable vertical banding, which I am told is normal for the CCD used.
Mate if I got told that's 'normal for the chip used' on a $10k+ camera I'd have no problem making it fit where it came from ... unreal... You guys are way easier customers than I'll ever be. I'd be outright pissed something serious.
This issue may not be directly a fault of the manufacture, but an issue with the CCD.
With extra work, I get good results, but I still wonder if these were fixed, would my results be better? But the matter has been closed by SBIG.
Do SBIG quote noise levels for this camera? What you are getting there seems way beyond what I would think to be reasonable. Whilst it may not be a fault in the camera (it could be external interference or a bad cable) it is worrying if they won't acknowledge that there is an issue and are not prepared to give you technical support to resolve it.
I would have thought Peter, who in my experience is ethical and technically competent, could help you at least isolate the origin of the noise. If the camera was fired up using his power supply and data acquisition hardware and still generates the banding, the question would then need to be put to SBIG: Is this camera's performance consistent with manufacturers expectations. If the answer is no, then they should resolve the issue. If the answer is yes, then it speaks poorly of SBIG.
In either case, they don't seem to be covering themselves with too much kudos of late.
Thanks for the feedback Marc and Clive. I do think this needs to be advertised more widely that this is acceptable performance from this chip. I had no idea it was possible to get this result after having my STL, and it never depicted these bans.
I'm really interested to hear how you go Paul.
All the best,
Steve
PS: I run off a 12v battery, have ferrite noise suppressors everywhere, tried many ways to connect the usb to eliminate the noise, but it remains there in the background. Lesser the signal, the worse the banding.
I'm sorry to hear your camera has failed again Paul. I can understand your disillusionment.
I have also had a less than acceptable results with my STXL with it going back to the USA many times. In fact I did not get an image from it in the first six months of ownership. Even now the camera produces what I feel as less than comparable results to that of my STL [which I also bought new]. My STL produces with ease very smooth results, whereas the STXL requires serious effort to reach the same level.
This issue may not be directly a fault of the manufacture, but an issue with the CCD. Overall, the STXL is a beautiful piece of work, and all other components work well. My two remaining issues is that the main chip has very noticeable vertical banding, which I am told is normal for the CCD used. This is my main disappointment with the camera, as it is normally present in short exposures [very bad banding], to long exposures [where the banding is less noticeable]. I have a attached typical example of a 240sec bin 2x2 exposure [totally raw sub, no calibration].
The second is that the self guide chip has obstruction, that shouldn't be there.
With extra work, I get good results, but I still wonder if these were fixed, would my results be better? But the matter has been closed by SBIG.
Good luck Paul, you'll be noticed because of your profile.
Steve
Funnily enough I have seen exactly the same lines on my darks and light frames. It tends to be intermittent thing but it is real. I have attached a copy of one of my images which shows the problem. So you can use that as evidence this has been happening on a camera other than your own. It is not likely to be a specific thing in your observatory or mine. Most likely defective electronics.
Funnily enough I have seen exactly the same lines on my darks and light frames. It tends to be intermittent thing but it is real. I have attached a copy of one of my images which shows the problem. So you can use that as evidence this has been happening on a camera other than your own. It is not likely to be a specific thing in your observatory or mine. Most likely defective electronics.
That's exactly it Paul. That image has the same issue. The intensity of the issue does vary for me too, but unsure what it is tied to? Perhaps the current level of the cooling system?
The intensity of the issue does vary for me too, but unsure what it is tied to?
The degree to which that sort of noise will be visible is highly dependent upon the signal level of the image. The way around it is to expose as long as you can without saturating the well depth of the pixels, in which case the shot noise will render the banding invisible. .... that's assuming the intensity of the banding doesn't accumulate with time?
The degree to which that sort of noise will be visible is highly dependent upon the signal level of the image. The way around it is to expose as long as you can without saturating the well depth of the pixels, in which case the shot noise will render the banding invisible. .... that's assuming the intensity of the banding doesn't accumulate with time?
That is correct Clive based on the objects I've done, and this is what Peter felt too. The phenomena does not accumulate for me. However, even in 20min exposures @F8, I can still see banding in many images. These cannot be calibrated and stacked only, with it being necessary to make additional treatments to the images before registration. Otherwise, the banding will be present in the combined image.
I have also seen with the same object, that banding varies, and thus the reason I wondered if it could also be tied to the cooling current? But I have nothing to confirm this. Just grasping for answers. Nevertheless, I never saw this in my STL data which worked on the same scope.
Hmmmm.... have you counted the number of bands in an image? If so, I'd be curious to know what you get when you divide that number by the download time (in seconds)
Incidentally, have you tried switching off the cooling (and the fan) during readout?
fwiw ) one feature I value highly in a camera is the ability to slow down the read out process. It enables you to minimise noise amongst other things.
