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Gina

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Gina last won the day on February 21

Gina had the most liked content!

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About Gina

  • Rank
    Neutron Star

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  • Website URL
    http://ginad.uk (currently not available)

Profile Information

  • Gender
    Female
  • Interests
    Astrophotography, Photography, Electronics, Computer Hardware and Software (Programming)
  • Location
    East Devon, UK
  1. Gina

    What You Have Learned From Astro?

    You are surprised at your patience and enthusiasm. Several hours pass by unnoticed when you are processing your images. You end up with an empty bank balance far faster than you ever though possible though I think this is already covered.
  2. Gina

    ZWO Peltier Cooler

    Might work. I haven't got an ASI120MC so I don't know what that's like but I would guess it's the same.
  3. Gina

    Gina's Ultimate All Sky Camera

    The great storm of a few days ago did a lot of damage to my ASC. Ripped the top off which landed the other side of the observatory upside down on the grass, seems mainly undamaged apart from a tiny mark on the dome. The rest didn't fare so well. The dew heater resistors and some of the wiring was strewn across the observatory roof and everything was full of water. That is the worse part - lens and camera were soaked. Eventually, after a couple of days of warming, the lens dried out and is now alright. The camera did not survive! Wet had go in and shorted something and destroyed it. There were signs of wet corrosion on the image sensor board. Cleaning this off didn't make any difference.
  4. Gina

    ZWO Peltier Cooler

    There isn't any gap under the sensor chip and there are connections on all four sides. Whether the little hole in the PCB would be any use for a cold finger I don't know but it's tiny compared with the chip. I guess the ASI178MM is the same going by the marking on the PCB. Here are some photos of the sensor PCB.
  5. Gina

    ZWO Peltier Cooler

    Yes, I wondered that myself. There is a small hole in the sensor PCB behind the sensor but its smaller than the chip so only the middle would get the full cooling. I'll take a closer look on my dead camera and see if there's any gap behind the sensor chip.
  6. Gina

    Yet another DIY all sky camera thread

    I seem to have succeeded in soldering the wire back onto the Peltier TEC. One more small step... back to where I was. Well, sort of! I would only be back where I was if I had a colour camera with 1/2" image sensor. Clearly, I need to redesign my ASC to prevent wet getting into the camera if I am going to resurrect it! There would seem to be no way of stopping horizontal rain drenching it every time we get a storm so the casing will need sealing very well to prevent wet getting in.
  7. Gina

    ZWO Peltier Cooler

    I seem to remember saying that the image sensor of the uncooled ZWO CMOS astro cameras had a thermal connection to the case but I was wrong - it hasn't!! The image sensor chip is on a separate PCB connected to the main board with a ribbon cable. If the case is cooled only air circulation within the casing can cool the sensor. I found this out when I had a disaster with my all sky camera in a recent storm which ripped the top off the ASC and the rain soaked everything including the camera. Wet got into the camera causing a short on the PCB and destroyed the camera! Not only are the non-cooled cameras not designed for any sort of cooling but the image sensor is not in a sealed chamber. There is no desiccant like there is in the cooled cameras and water/damp can get in around the connectors which are a loose fit in the casing. The conclusion is that only a minor amount of cooling can be applied with an external Peltier TEC. Unlike the cooled ZWO cameras which have a sealed imaging enclosure, these non-cooled cameras must be kept dry (and that includes avoiding dew!). From experience with my ASC, externally cooling the camera such that the camera data shows a few degrees below freezing is perfectly viable but more than that requires the full ZWO cooling system with a sealed imaging enclosure. At least any small amount of damp that gets into the camera will condense on the inside of the case and not on the image sensor or front window. Hope that clears up any misconception I may have created and my apologies for misleading.
  8. Gina

    Yet another DIY all sky camera thread

    The next question is about cooling the camera. I know I said there's a small hole in the PCB behind the image sensor in the ASI185MC and presume the ASI178MM is the same but this hole is a lot smaller than the sensor chip so a cold finger in this hole would only cool the middle of the chip. The other question is whether it's worth bothering, particularly as adding anything inside the camera case risks damaging the camera! I've already "deaded" one camera and I done want to kill another! Cooling the case seemed to work well enough for the ASI185MC so should be adequate for the ASI178MM. Also, any moisture that does get into the camera case would condense on the inside of the case rather than the image sensor chip or window. Unlike the cooled ZWO cameras, these do not seem to provide a sealed enclosure which was a surprise. There is no desiccant to remove moisture in these cameras. Damp or even water (as I know to my chagrin) can get into the camera. Whether it gets in around the window or one/both of the connectors (USB and ST4) I don't know but get in it certainly can!!! Thus the extra £300 for the cooled versions is far from just a double step Peltier TEC and heat radiator plus fan, but a whole different case and internal construction with a sealed chamber for the imaging sensor. The sensor chip presumably has a cold finger leading to the cold side of of the cooling system. The upshot of all this is that the uncooled ZWO cameras are not really suitable for cooling by external means other than to reduce the temperature to a few degrees below freezing. In conclusion, my idea of adding an Ha filter into the ASC for providing a narrow band ultra widefield imaging system would seem to be a non-starter without a proper cooled camera. I just don't think there would be enough light coming in through an Ha filter to give an adequate image with an ASI178MM camera with it's small pixels. But I guess I could be wrong.
  9. Gina

    Yet another DIY all sky camera thread

    I may be back in business - the lens has cleared I had pretty much given up on it and just left it on the table. I was comparing the height with the zoom lens when I thought I'd have another look through it and it looked clear. So I put it on the ASI178MM camera and focused the view. It looks alright!
  10. Gina

    Longcase Pendulum Clock

    I need to work out how long the pendulum rod needs to be as it varies with gravity which depends on latitude and height above sea level. Using an online calculator gives it as 9.81098 here. T = 2π√(L/g) = 2π√L / √g 2π√L = T√g √L = T√g/(2π) L = {T√g/(2π)}^2 Locally g = 9.81098 so √g/(2π) = 0.498512815 For T=2 (period = 2x beat), L = (2*0.498512815)^2 = 0.994060106m IOW 994mm.
  11. Gina

    Oops

    I've had that with virtually all cables that go outside except armoured ones or ones in substantial pipes underground.
  12. Gina

    Yet another DIY all sky camera thread

    Tried the ZWO supplied very wide angle lens 2.5mm f1.2 but it would only cover half the sky or less. The call it a 170° lens but that is probably diagonal.
  13. Gina

    Yet another DIY all sky camera thread

    I'm not sure what's going on in the lens but when I look through it I see what looks like a sort of crystalline structure. I put the lens on the ASI178MM camera and can see light and dark but it won't focus and also shows this effect. I think the lens is kaput!
  14. Gina

    A dream come true

    With sloping ground it's all a bit subject to interpretation.
  15. Gina

    Astrokev's ROR - The Build

    That's what I did with mine.
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