Horizontal Banding on ASI183MM-Pro

aruse

I just bought the ASI183MM-Pro for my first imaging camera besides a DSLR and I have a few questions since I'm still new to this.

1) After taking some test shots, I noticed some black horizontal banding. If I zoom in, it looks like black dots, which I am assuming it's the pixels, but they are all on the same row. Not all the pictures have this and they change location for different shots. This reassures me that the pixels aren't bad at least, but I am not sure what causes this. It has happened on any of the 3 gain settings (HDR, Unity, LRN) at any exposure length. Does any one have this issue or know what causes it? Is this normal for these type of cameras? See the attached example.

2) This is also kind of related to question 1, but slightly different. I am trying to make a master dark frame for different exposure lengths, and noticed the same banding but now they are white pixels. They occurred on the first couple of dark frames then they went away. After that, my dark frames resembled the dark frame provided on the ASI183MM-Pro product page on this website. This makes me think that it may just be something going on when the camera first takes pictures even though it is cooled to -20C already. Should I just delete these first few images and not use them to create my master dark frame? I havent checked yet, but maybe the issue I mentioned in question 1 is the same thing, and I should just delete the first pictures taken on start up.

3) Last one, what is with the bright spot on the right hand side of the dark frame? It's on the example from the website, so I know my camera is consistent with that one. Is there something locate behind the sensor there creating that?

Thanks in advance for any advice given

-Aaron

billm

I also have this problem. It is only noticeable on vet short exposures on HDR Gain.

If I want to do LRGB imaging, I find any exposure greater than 5sec on Lum will blow out the cores of the brighter stars , even on HDR Gain. But this is when I get these lines.

So, can’t lower the gain any further, can’t increase the exposure.

Everything seems ok when narrowband imaging with 5min exposures on Gain 200.

aruse

Hi Bill,

Thanks for the response. It's good to hear that you can still get some good images even if you are seeing the same things that I get with my camera, especially since they are narrowband images. I live in a major city so I'll be limited to narrowband imaging for now anyways. I'm still new to these things so I'm trying to learn as much as I can. It's been cloudy here for a while so I am limited to getting used to sequence generator pro and creating darks. It does seem that the first 3 or 4 images I take after turning the camera on and cooling it down give me the white banding no matter what exposure length. After that, then I get good darks. Basically I just take 3 to 4 30 second exposures until the banding goes away, then reset the sequence with the exposure length and number of images I want, then run the sequence. I'll test this out on the lights when I finally get a clear sky. Hopefully it follow the same trend. Attached is a master dark I made after excluding the first 3 darks with banding. It's 42 5 min exposures with HDR gain at -20C. It looks like it captures the amp glow on the right and the grid like pattern that I see in other dark examples so maybe it is a good master.

-Aaron

Support@ZWO

Hi there

We received same report about bandings, our engineer is working on it, it probably a driver issue, we will try to fix it in next version.

chad

Hi Aaron，

Can you send an email to : chad.cao(at)zwoptical.com.

I need more details to confirm with you.

Thanks

Chad

billm

Hi Chad

I have been using my ASI183 Pro for a few months now and have a library of Bias and Darks at different exposures and gain. If you need any, please let me know.

Bill

chad

Hi Bill,

Thanks. Did you have the same problem?

Thanks

Chad

billm

Yes. I have a distinct narrow horizontal banding that is visible on individual images. When stacked, a distinct wide vertical banding appears. This is most evident on short exposures.

I have tried calibrating with different combinations of Bias, Darks and no Bias, but with same result.

All ok on longer exposures but when I tried 2x2 , the problem was worse.

chad

Hi Bill，

Can you show your images at here?

Thanks

Chad

billm

Hi Chad,

Images as requested.

Single Bias:

Single Bias - CalibrationFrameHDR-1x1-001Bias.jpg

Stack of 100 Bias frames:

Stack of 100No Bias - bias-BINNING_1 - HDR.jpg

billm

Single 5sec Dark:

Single 5sec Dark - CalibrationFrameHDR-1x1-001Dark5.jpg

Stack of 36 Darks:

Stack of 36No Darks - dark-BINNING_1-EXPTIME_5 - HDR.jpg

billm

Single 5sec Luminance:

Single 5sec Luminance - M103-0001Lum-HDR.jpg

Stack of 36 Calibrated Luminance:

Stack of 36No Calibrated Lights - light-FILTER_Luminance-BINNING_1.jpg

Hope these help. If you need anything else, just let me know.

Bill

chad

Hi Bill，

Thanks， it is enough.

For you case, I had got the same problem like you: The single image is not obvious, but after stacking, the vertical pattern is very serious.

We just received the feedback about this problem 2 days ago. We are also not sure what happened. And the camera that have the same problem is on the way back to us now. So please wait for a few days. If we have a result, I will let you know.

Thanks

Chad

billm

Hi Chad,

It might actually be my camera that’s on its way to you from FLO? It has been sent back to you with a USB socket fault?

Bill

chad

Hi Bill,

Are you sure? the camera should be from Maicon Germiniani.

And if you camera is also on the way back, I will check this problem too.

Thanks

Chad

gkunz

Hi, I have exactly the same fixed pattern noise in my ASI183MM. Did you ever analyze the camera that was returned to you? What was the result?

Support@ZWO

gkunz wrote:

Hi, I have exactly the same fixed pattern noise in my ASI183MM. Did you ever analyze the camera that was returned to you? What was the result?

Can you share the fit image to us via Dropbox or Google Drive link? You can send en email to support@zwoptical.com for tech help.