Anyone using QHY 16200A?

Discussion in 'Image Capture' started by Maneesh Yadav, Oct 23, 2018.

  1. Maneesh Yadav

    Maneesh Yadav Cyanogen Customer

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    I've set mine up and have the 5LII attached on the OAG but it seems that my pixels look really dark.
    I tried to get a coarse focus on the moon, the guider camera picture looks fine but the 16200A reads as 0 in most of the image (I thought the bias would show something) and I am pointed right at the moon on my refractor. I do see a faint shape that resembles the prism when I do a 1s exposure.

    Is anyone using this camera successfully with MaximDL? The QHY forums so far haven't been very helpful, I'll try their suggestion of using the native capture software.

    It must be a setting somewhere or something bone headed. I can see the chip surface, the filter wheel does not appear to occlude it and the light is going through the OAG prism to the guider and things look fine there. Quite puzzled, perhaps someone has already dealt with this.
     
  2. Colin Haig

    Colin Haig Staff Member

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    Maneesh, I have a couple older QHY cameras, and drivers have problems with consistency and reliability in my experience. I don't have that particular camera, but suggest you contact them for support.
    Start with their software and put the camera on the workbench in daylight and see what you get.
    Also consider uploading a FITS file here for people to look at.
     
  3. Colin Haig

    Colin Haig Staff Member

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    I should have added please mention what versions of everything (e.g. ASCOM 6.4 SP 1, MaxIm 6.18, QHY Driver x.y etc)
     
  4. Colin Haig

    Colin Haig Staff Member

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    Note that you might have to update the QHY System driver as well as the camera ASCOM driver.
     
  5. Maneesh Yadav

    Maneesh Yadav Cyanogen Customer

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    Yes went through QHYs rather complicated driver upgrade train and the 5LII works well now.

    Here is my current state:
    ASCOM 6.3.0.2831
    MaximDL Pro 6 (6.16)
    I can't get at the exact QHY diver version at this moment, but the "UpdateCheck" utility reports up to date.

    I added a screenshot of what the guider camera could see through the OAG (looks fine) and what a FITS file from the the 16200A when pointing at the moon with a 1s exposure (note all the "0" values).

    EDIT: link to a flat field (the camera was on the C14 in this case). You can clearly see an image. It isn't like the camera isn't picking anything up...it feels like there is a big subtraction somewhere making it seem very insensitive (0.1s on the flat field box feels like it should saturate):
    https://drive.google.com/open?id=1zvV3ZOKVNuEGiK4DkGYVkSqdkh_h4_S9
     

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    Last edited: Oct 23, 2018
  6. Colin Haig

    Colin Haig Staff Member

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    Glad to hear the 5LII is working right. Agree OAG image looks fine.

    I had a look a the prism image and the c14 flat image.
    The flat image looks kind like i would expect - small donuts are on the chip or near it; bigger donuts from the C14. (Out of curiosity, is this a C14 EDGE HD or is there a reducer?)

    I don't think it matters a lot, but if you want to get current, also suggest you upgrade to Maxim 6.18, and maybe ASCOM 6.4 SP1.

    I'm really stumped by the loads of zero values in the prism image. There should be at least a few electrons of noise...
    Am wondering if the camera gain/offset are incorrectly set by something in the software stack.
    Or if you have poor mechanical alignment between the main scope and the guide scope ? e.g. eyeball the main scope when pointing at the moon, using an eyepiece, then replace with the camera.

    What happens if you put the camera on the workbench (not on the scope), with it set to luminance (clear) filter, and let some light get there?
     
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  7. Maneesh Yadav

    Maneesh Yadav Cyanogen Customer

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    Yes the C14 is the a C14 EdgeHD.

    I've moved the camera back on the refractor and I think I am in good shape now. The source of my confusion (FWIW):

    The manual suggests only one line where it talks about offset/gain:

    "Normally, you can set the gain=1 and offset=10 to start. Keep clicking "Okay" to return to Camera Control window."
    (The corresponding image in the manual shows the offset at 140.)

    That suggests that starting there, and just fiddling values up and down a little, you will at least see something in the image. Not true.

    The "phase transition" along the offset setting between "all 0s" and some bias noise is quite discrete. The image will be all 0s and then you finally start reading bias noise (on my camera) at around offset=116. Not sure if I found the link on this very forum, but for the sake of hive redundancy, following the directions here was a tremendous help:
    http://www.astropixel.gr/uploads/7/8/3/5/7835053/scientifically_determining_ccd_gain_and_offset.pdf


    The manual doesn't stress how important following such a procedure is. A new user will be alarmed at what they are seeing and be confused about other potential causes (wires, drivers, something in the optical path etc.).
     

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