Settings to Remove Banding in Integration? Recommendations?

So how do regular, non calibrated lights look like? And can you show a masterdark and masterbias? It looks like there is extra noise in the data, like what you can get if there's a power-leak (no common ground everywhere) messing up the readout of the sensor.

ps. we're away from 02-02 for about a week to Astrofest London so please allow for a few days to a week for a response, sorry for the delay.

@vincent-mod 

Masterdark and non-calibrated lights look good, or at least nothing I've noticed.  No bias needed with the ASI294MC.   There's a link above to the data - lights, darks, flats and calibrated.

I was thinking interference as well.  The next time I'm out I plan to not power the Celestron Dew heater ring for corrector lens, which the Hyperstar and 294MC are connected.   The other thought is to replace the main camera power and usb cables in case there is a cable shielding issue. 

No worry on response time and hope the conference is going well. 

Thanks, I can download the data after the conference. A dew heater I wouldn't connect to the same power box as the other devices, in case of a malfunction that may introduce quite the amount of power to the other devices. Things like a mount and heater I usually power completely separate (but that's me). 🙂 Thanks for your understanding!

Hello Roger, I can say from my own experience that I once had similar problems with ASI294. In my case it was the wifi signal from the MiniPC that caused additional banding. The problem was the original USB cable from ZWO that came with the camera. The shielding was simply too poor. I assume you also use these ZWO USB cables? I used an old printer cable as a test and the banding was greatly reduced. So I bought a high-quality USB cable from the hi-fi sector and have had no more problems since then. Although the wifi antenna and cable are only 2 cm apart on the MiniPC.
Nevertheless, the camera itself has banding, which you can see in the dark frames. You can only avoid this with large dithering steps and increasing the exposure time, although you are already doing quite well with your settings in conjunction with Hyperstar. It could be that the STC filter lets little light through, and that the exposure time is still not sufficient despite Hyperstar. Especially on a moonless night.
You have to experiment a bit.

I hope this helps.

With best regards.

@minusman 

Thanks for the feedback.  I'll give your recommendations a try and will post results when I have a clear night.   Here's my setup.  I may have to move the ASIAIR Pro to back of scope, but that's the last step if the others don't solve the banding issue.   I found another post recommend use of BIN2, not sure why and not the best option.

Adding a follow up!  My initial thought was that the imaging camera might be defective as I've never encountered banding in long [bulb] exposures using a DSLR or mirrorless camera.   I also know that cooling plays a key contributing factor.  While cooling impacts final SNR, certain levels of exposure and gain also resulted in various levels of banding. I performed some random tests indoors using a 2" dark filter to enhance visualization using ASIAIR app.  Horizontal banding severity levels consistently occurred during short exposure times (0.5s to 3s) at unity gain (120) of the ASI294MC and various other exposure/gain settings as shown in the 15 random tests screen shot attachments.  (Side note:  Shooting the moon is the only short exposure I've used with the main camera; I don't recall whether I used the Hyperstar v4, which results in a very fast f/1.9 vs. f/10 without.)    

I repeated the tests a second time using the same exposure, gain, and relatively close cooling temp with the same results. 
Conversely, the [banding] severity level dropped as gain was increased during shorter exposures.    I was surprised no banding occurred for a 30s exposure at zero gain, yet banding was present for a 60s exposure with zero gain.   Just in case, I've provided the same information to ZWO to ask if the results are normal.  While I've been somewhat successful in removing the bands post processing, I'd rather not..   

Mmm, that is quite strange, I would probably take the camera to be checked out if it's still under warranty. Just to make sure it's not a fault. Also, usually when things are a bit random, it can still be a power issue or something like a bad data connection.

@vincent-mod yeah, ZWO support says the board is most likely defective and has to be replaced.   🤪🤔

Happy to report that ZWO repaired the camera and so far no banding or other issues.   It is great when ALL the tech in this hobby works.    NGC 7023 Iris Nebula, 4/20/23.   Thanks @vincent-mod and @  minusman for your responses.

Awesome! Always nice to see things resolved indeed.