Guider Sensitivity ?

Discussion in 'Guiding and Adaptive Optics - StarChaser and AO' started by Galaxyhunter, Mar 2, 2021.

  1. Galaxyhunter

    Galaxyhunter Standard User

    Joined:
    Aug 7, 2019
    Messages:
    87
    Location:
    Durand, Illinois
    How is the SC2 chip sensitivity compared to the guide chip from the ST series cameras? On the ST cameras I have ( ST10xx and ST2000xx ), I loved the fact that if I binned 3x3, I could set the AO8 to 10 Hz and guide off a 12th mag star. If I went to 5 Hz, I could use a 14th mag star. I'm kind of hoping for the same thing.

    Thanks, Carl.
     
  2. Colin Haig

    Colin Haig Staff Member

    Joined:
    Oct 27, 2014
    Messages:
    5,207
    Location:
    Earth
    It's similar but different. The sensor is located in front of the filters, unlike the old cameras. So that will give you an advantage. The pixels are smaller, and there are more of them, so again, it's going to be different.
     
  3. Galaxyhunter

    Galaxyhunter Standard User

    Joined:
    Aug 7, 2019
    Messages:
    87
    Location:
    Durand, Illinois
    I never used filters before. So what I was wondering is an even - Apples to Apples comparison.

    You say it's going to be different. In what way?
     
  4. Colin Haig

    Colin Haig Staff Member

    Joined:
    Oct 27, 2014
    Messages:
    5,207
    Location:
    Earth
    The SC guiders have a 1280 x 1024 array of 4.5um pixels, area of the chip is about 6.2mm x 4.6mm.
    The original guide chips from those good old cameras were 192 x 165 with 13.75 x 16.5 um rectangular pixels in a tiny 2.64 x 2.64mm square.
    The later upgraded guider chips in those old cameras were 640 x 480, 7.4um square pixels, in a 4.7 x 3.5 mm array.

    Differences are that the SC-2 sensor has:
    - larger surface area making it easier to find a guide star
    - each pixel is smaller thus higher resolution for more precise guiding.
    - it is more sensitive across a broader part of the spectrum
     
  5. Galaxyhunter

    Galaxyhunter Standard User

    Joined:
    Aug 7, 2019
    Messages:
    87
    Location:
    Durand, Illinois
    Thank you Colin, that's good news.
     
  6. Doug

    Doug Staff Member

    Joined:
    Sep 25, 2014
    Messages:
    8,350
    FYI to increase the flexibility of the system, we are adding a software binning capability to the driver. The sensor natively does 1x1 and 2x2 binning. We're going to extend that with software binning to 3x3 and 4x4.
     
  7. Bob Denny

    Bob Denny Cyanogen Customer

    Joined:
    Oct 12, 2014
    Messages:
    925
    Location:
    DC-3 Dreams, SP, Mesa, Arizona +1 480 396 9700
    This sounds like a great addition to the product line!! And being in front of the filters is excellent.
     
    Colin Haig likes this.
  8. mike shade

    mike shade Cyanogen Customer

    Joined:
    Sep 14, 2015
    Messages:
    75
    Doug, any idea when the driver might be available? As on another thread, have had issues with the guiding, as you are aware. Have done everything on my end (rebalanced, remeshed the gears, new PEC curve, addressed possible cable drag issues). It has helped a little bit-maybe, maybe not but I still don't have a reliable workable system in regards to guiding. As I mentioned I am guiding at .645"/pixel, seeing is killing it.

    Thanks
     
  9. Doug

    Doug Staff Member

    Joined:
    Sep 25, 2014
    Messages:
    8,350
    Progress is good. It's in the review stage. Next step would be beta testing.
     

Share This Page