Image artifacts?

Discussion in 'Aluma AC Series CMOS' started by mike shade, Mar 7, 2021.

  1. mike shade

    mike shade Cyanogen Customer

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    Attached is a five minute unguided image of M81 through the CDK17/Aluma AC4040. I had it set to simple auto dark, camera cooled to -20 and used Stackpro. There are a number of horizontal lines and not sure what these might be. I also noticed that in the darks I shot, there are a number of vertical lines that look very much like dead pixels but there seems to be a lot of them. As this is a new camera wanted to make sure there wasn't something I had not set right. Everything in regards to gain and the like has not been changed.
     

    Attached Files:

  2. Doug

    Doug Staff Member

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    These sensors are certainly "different" from the old CCD sensors. It takes a bit more work to get a clean result.

    Can you post a FITS frame?
     
  3. mike shade

    mike shade Cyanogen Customer

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    It is a big file...and I 1/2 sized it but here. As I mentioned, none of the gain settings have been modified (purposely) on my part, have not monkeyed with them, don't know if this would make a difference or not.
     

    Attached Files:

  4. Doug

    Doug Staff Member

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    I'd like to see a non-calibrated frame with no processing, please.
     
  5. mike shade

    mike shade Cyanogen Customer

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    Would that be a luminance frame? How long, 300" and which capture method? Of course this will be a big file. I do have darks and bias frames, raw out of the camera.
     
  6. Doug

    Doug Staff Member

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    Ideally a light and a dark. Probably have to use dropbox or similar.

    When using StackPro with the AC4040 I recommend setting the minimum subexposure duration to 30 seconds. I find you don't get the best results if you set it very low.
     
  7. Doug

    Doug Staff Member

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    Stop press... I was just told we have discovered a firmware bug in the Aluma AC4040 that impacts StackPro, which can cause banding.

    Stand by for a firmware update.
     
    Last edited: Mar 9, 2021
  8. mike shade

    mike shade Cyanogen Customer

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    Oh, that's good. Detailed instructions on how to upgrade the firmware would be helpful when it is available. Thanks,
     
  9. Doug

    Doug Staff Member

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    Page 39 of the user manual.
     
  10. Frank R. Santore

    Frank R. Santore Cyanogen Customer

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    I'm wondering if the firmware update took care of the OP's specific problem?
     
  11. Doug

    Doug Staff Member

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    I expect so - the firmware bug would definitely cause the issue he was seeing.
     

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