340M Allsky Image noise

Discussion in 'Specialty Cameras SG-4, AllSky, ST-I' started by James Pierce, Mar 25, 2020.

  1. James Pierce

    James Pierce Cyanogen Customer

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    Hi All,

    Something I've been curious about for a while, compared to all the sample images, and images I've seen from other cameras I've always felt like my 340m was quite grainy and noisy. I'm wondering if you might have any clue as to why this could be the case ?

    Changing the exposure time and DDP settings don't seem to make any significant difference. The noise can be a bit more or less, but it's always there


    340m All Sky Sample Image.png
     
  2. Colin Haig

    Colin Haig Staff Member

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    I've asked my colleagues to take a look.
     
  3. Tim

    Tim Staff Member

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    Definitely not normal. Be sure to check your serial cable and ensure it is securely connected. If that does not help, you should send it in for service.

    If you would like to send it in, please submit the following RMA contact form, and once we receive it we will send you an RMA number with return instructions:

    http://diffractionlimited.com/request-rma
     
  4. James Pierce

    James Pierce Cyanogen Customer

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    An extra bit of info which has just occurred to me... I don't think I've noticed it during the day. Only at night when the exposure extends (image attached from the camera just now). I'll double check the cable, but since having a long running camera crashing issues (caused by a faulty computer not a faulty camera) I've been pretty careful on that front. If it were a transfer / interference type issue I'd expect to see it in the daytime images as well as the night images.

    If it has to come back to you what's the likely turn around? ... given I'm out here in Australia it has a fair way to fly ... I'm pretty reluctant to be without an all sky camera for a significant period.
     

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    Last edited: Mar 25, 2020
  5. James Pierce

    James Pierce Cyanogen Customer

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    One more photo from the camera tonight to show that it's not always consistent. allskyCurrentImage.jpg
     
  6. Tim

    Tim Staff Member

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    Turn around time is currently 2-4 weeks. Given the current global situation, this does not account for any shipping delays that may occur, which is beyond our control.
     
  7. James Pierce

    James Pierce Cyanogen Customer

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    I'll hold off for now. The camera does it's job - the problem is largely cosmetic.

    Unrelated... How are the plan for a new all sky camera. It seems to me with modern CMOS etc there should be the chance for simpler / cheaper / better images in this space?
     
  8. Colin Haig

    Colin Haig Staff Member

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    I'd really like your thoughts on what your requirements are.
    The recently discontinued AllSky 340 camera is really robust and can send its video data a fair distance over a wired connection.
    What would you like to see in a replacement?
    Give me a shopping list ;-)
     
  9. James Pierce

    James Pierce Cyanogen Customer

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    Must haves:
    Obviously it needs to work at more than USB distance. Serial or Ethernet. My SQM works well over ethernet - probably a better standard these days.
    Full sky view.

    Nice to haves:
    More sensitivity.
    More resolution.
    Less noise (cooled or not).
    Simpler focus.
     

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