Weird noise pattern in several sub frames

I was going through some of my sub frames from the other night and came across several subs that contained weird interference noise of some sort. The camera was capturing all night long. At 2:30AM about half way through the session, there were 7 sub exposures that showed up in sequence that all had the same symmetrical pattern of white dots covering the entire frame, all the subs before and after these 7 were fine. I was capturing data on the Bubble Nebula NGC7635 with an ASI1600MM Pro, 300 second exposures at 120 gain cooled to -15. Camera was controlled with an ASIAIR Plus.

I've had this particular camera for about a year and haven't had any issues with it, this is the first time I've seen this. The attached photo is a single sub with a basic histogram stretch completed. Any thoughts?

Aliens are trying to contact you

Cable maybe.

I suppose a bad cable wouln't be out of the realm of possibilities. Haven't had any issues with them prior to this but maybe?

Cables don't last forever

When was this? There were solar flares a week ago and all were excited for the northern lights. I think another geomagnetic storm was predicted for today. Depending on where you were, your camera was affected during this event? 🤔
Defective cables are the most likely culprit, but if there were normal subs after the bad frames, it's a bit odd.

As a experienced AP nerd, I can confirm, it's aliens.
Since the pattern looks so symmetrical my gut feeling tells me it could be dew related, like very slight dew for a few minutes.
I feel like aI saw similar issues in the past and it had to do with dew.

Cable maybe.

Yeah, I would swap out your USB-3 cable to your camera. I had a similar, but different, issue with some of my subs once, and the cable swap fixed it. Make sure it's not strained and/or bent too much, especially near the connectors.

Richard Carande:
Cable maybe.

Yeah, I would swap out your USB-3 cable to your camera. I had a similar, but different, issue with some of my subs once, and the cable swap fixed it. Make sure it's not strained and/or bent too much, especially near the connectors.

I'll give that a try. It's a relatively new cable and hasn't given me a bit of trouble previous, but it's an easy swap and good place to start.

Almost looks like it's trying to debayer a mono image.

I have seen something like this before when a coloured camera isn’t debayered correctly.

Carastro:
I have seen something like this before when a coloured camera isn’t debayered correctly.

It's a mono camera, and it was only 7 sequential subs in the middle of a 90 exposure set. The subs came off the SD card with the artifact (no debayering), the FITS files show the same interference.

The problem seems to have progressed from simply being annoying and throwing out a few frames, to the camera being unusable. It's now affecting every frame and has resulted in several nights of troubleshooting with no improvement. I'm at a loss.

I've changed USB cables, separated all cabling, isolated the power source directly to the camera. Nothing has changed with the setup over the last 10 months other than adding an electronic focuser a few months ago.

I've reached out to the retailer to see what service/warranty options are available as I'm out of ideas.

Sounds like the camera is going bad

If you want to waste more time, you could try making a tinfoil hat for the camera to rule out aliens/CIA.

Seriously though, if (very very slight possibility) it is EM radiation of some sort, wrapping the camera in a single layer of aluminum foil would block it. If that works, you have bigger issues ¯\_(ツ)_/¯

I think it could be something like a floating potential problem, an improper electrical mass.
I once had some strange patterns in some image frames with my QHY10. This camera had an external box, in which some amplifier electronics were housed. This introduced some temperature issues, and also potential issues.
I had some discussion with QHY support about this, but it didnt lead to any solution. You dont see cameras with external amps anymore, though.

Some EM pickup sounds plausible too, but this might be the same problem, only seen from a different point of view.

Hi,

If I were you:
1- try the camera with different setup, Lens, imaging software.. etc.
2- try to update/reinstall ASCOM or native for the camera.
3- Make sure the camera power is within range and stable.
4- Make sure the cooler is working, Not trust the temp. display in the imaging software,, try ZWO ASIStudio prog.
5- NOT trust cables even they are new.. Change them more than twice after checking them with different camera to confirm they are working,
6- Remove the AF, Since its the only changed that maybe affect the camera.. Even you don't think its the issue

Good luck.

Notwithstanding the excellent feedback you've gotten regarding aliens and "em" radiation, if you've swapped out and validated your external cables, some of the older zwo cameras can have the plug connecting the sensor to the circuit board work loose. If you're out of options give that a try. Some time spent on Google should uncover a how to guide zwo put out there a few years ago on this. Best of luck!

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