IMX455 based SBIG camera?

Discussion in 'Aluma AC Series CMOS' started by William Castleman, Jan 28, 2021.

  1. Kevin Morefield

    Kevin Morefield Cyanogen Customer

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    Doug,

    Probably the easiest way to see the banding I'm talking about is to look at a series of stretched bias (or dark) subs. As you blink through them you can see the bands kind of scroll down the screen. They aren't seen in mild stretches of the light data but once you go deep on something and stretch to show the faintest detail they pop up. If stretched bias subs don't show banding on your IMX455 version that would be a huge improvement over others and worth a higher price.

    I uploaded a single, stretched dark sub that shows the banding I'm referring to. If it would be useful for you to see more data let me know.

    Kevin
     
  2. Doug

    Doug Staff Member

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    That looks like significant banding, but I'll need quantitative information. You can't get that from a processed JPEG.

    What I'd really like to see is two unprocessed bias frames in FITS format. You will need to upload them somewhere... they'll be too big for the forum.
     
  3. Kevin Morefield

    Kevin Morefield Cyanogen Customer

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  4. Doug

    Doug Staff Member

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    Okay I've done the exact same processing using your camera, and the SBIG Aluma AC455. There is some banding in our camera... but significantly less. Here are some cropped images from both cameras (just so they're not huge), processed identically.

    Your camera:

    upload_2023-10-29_13-11-30.png


    SBIG Aluma AC455:


    upload_2023-10-29_13-11-50.png
     
  5. Kevin Morefield

    Kevin Morefield Cyanogen Customer

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    Definitely looks better Doug. How did you match the gain and offset to my camera's versions?

    Also, one manufacturer associates this banding with USB downl0ad speeds. They say USB speed can be user tuned to minimize the banding. I tried it and only found that the Sdev of the bias was correlated to the USB speed so it didn't really seem like it was being tuned so much as there is a directional correlation with banding (or noise) and USB speed.

    Do you have any theories about where the banding comes from and why the SBIG has less?

    Thanks,

    Kevin
     
  6. Doug

    Doug Staff Member

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    Most likely it is due to disturbances on one of the sensor's power supplies. Depending on the frequencies involved it can be extremely difficult to eliminate.

    We're not using USB in our camera.
     
  7. Mike Hambrick

    Mike Hambrick Cyanogen Customer

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    A while back I asked if Diffraction Ltd. is developing a camera based on the full frame IMX455 CMOS sensor. I believe that you said that one was in the works. Is that still the case, and if so, do you have a time frame in mind for when you might introduce such a camera ?

    Mike
     
  8. Doug

    Doug Staff Member

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    Yes, we're almost ready to roll.

    We're about to launch a new web site; the Aluma AC455 page will go up at the same time.
     
  9. DJ Cash

    DJ Cash Standard User

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    Hi Doug, it has been a while since I last checked in and wanted to see if you could give us an update on the ac455? Any guidance here would be greatly appreciated!!
     
  10. Doug

    Doug Staff Member

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    I don't like to make promises because you never know when you'll run into some fool problem... but we're very close.

    We're getting the final firmware/software bits finalized right now. I'm hoping that stuff will be completed this week.

    After that we do our final product validation testing.

    Then, assuming all goes well, we launch.
     
  11. Doug

    Doug Staff Member

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    FYI, the product name is:

    SBIG Aluma AC455

    It will be available in both AC455M and AC455C versions (monochrome and color).
     
  12. DJ Cash

    DJ Cash Standard User

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    That’s amazing! I can’t wait. I assume it’s compatible with AO-X, SC-4 and AWF’s? Lastly, do you happen to know if you will be selling this in expert kit form as some of the other Aluma cameras are?
     
  13. Kevin Morefield

    Kevin Morefield Cyanogen Customer

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    Doug,

    You mentioned that you weren’t using USB for connection. What are the connection options?

    Thanks,

    Kevin
     
  14. Doug

    Doug Staff Member

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    Yes, the Aluma AC455 is compatible with the AFW, SC-4, and AO-X.

    We're using Fiber Ethernet. It's fast, allows for crazy long cable lengths, and is very reliable. It doesn't have the problems associated with USB Selective Suspend, which randomly turns off power to the port in the middle of the night (and if you turn it off, Windows Updates keeps randomly reenabling it).

    We realize that many people aren't familiar with this interface, but it's basically just another version of Ethernet. It's not hard to set up, and we provide full instructions plus are working on some videos if you prefer that format. If your computer doesn't already have a compatible port, adapters are available for PCIe and Thunderbolt, and you can get a fiber-to-copper Ethernet converter. For convenience you can optionally buy cables and adapters with the camera, and we also identify other places where you can buy them (probably cheaper too).
     
  15. Colin Haig

    Colin Haig Staff Member

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    Kevin - do you mind my asking - what camera was that - the one you sent images for Doug to look at ?
     
  16. EricC

    EricC Cyanogen Customer

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    Hi, I thought I heard a while ago that SBIG was coming out with an imx455-based camera. Is that true, and if so, when?

    I'm looking for a high-quality camera and have heard of too many issues with ZWO and QHY imx455 cameras. And I own 3 other SBIG cameras that I like.
     
  17. Doug

    Doug Staff Member

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    Yes, we're putting the finishing touches on it right now.
     

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