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Old 18-09-2018, 08:23 AM
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that_guy (Tony)
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QHY9 Light leak

Hi guys, ive just finished the imaging run from last night and wanted to get started taking darks but I've noticed that there is severe light leak (to a point where every dark frame is useless). I've tried reducing it by "wrapping the camera with foam lining along the sides but still getting the issue. I've put my 365 cover as well as wrapping the camera in a black t-shirt. still, I'm getting light leaking in from the sun. Does anyone else have this problem with the QHY9? If so, what was your solution?

Thanks
Tony

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Old 18-09-2018, 08:28 AM
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multiweb (Marc)
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I can't see how this would be a light leak. The sensor chamber in the QHY9 is sealed and in the middle of the camera physically. There's no way stray light would get in there. Maybe an uneven cooling issue?
You can shoot darks indoors at night anyway. That's what I do, on the kitchen table. Just the camera.
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Old 18-09-2018, 08:45 AM
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Quote:
Originally Posted by multiweb View Post
I can't see how this would be a light leak. The sensor chamber in the QHY9 is sealed and in the middle of the camera physically. There's no way stray light would get in there. Maybe an uneven cooling issue?
You can shoot darks indoors at night anyway. That's what I do, on the kitchen table. Just the camera.
I prefer to shoot the darks on the scope just so I dont have to reorient it the next night im shooting. Is there a way of checking uneven cooling? I don't have this issue if I take darks at night but obviously I don't want to waste a good night of imaging imaging darks!
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Old 18-09-2018, 11:18 AM
Imme (Jon)
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I don't think it's a light leak if you have physically wrapped the camera up.....internal issues I'd suggest
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Old 18-09-2018, 11:53 AM
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multiweb (Marc)
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Quote:
Originally Posted by that_guy View Post
I prefer to shoot the darks on the scope just so I dont have to reorient it the next night im shooting. Is there a way of checking uneven cooling? I don't have this issue if I take darks at night but obviously I don't want to waste a good night of imaging imaging darks!
Fair enough. Try to shoot your darks at night when it's cloudy not during the day. It's not like you need to shoot darks often. Every 6 months or so is good enough to build a library of darks. I also wouldn't cover the camera while it's powered up. It might overheat on the heat sink side.
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Old 18-09-2018, 05:22 PM
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It looks suspiciously like amp glow, though I have never heard of a QHY9 suffering from this.
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Old 19-09-2018, 08:16 AM
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The more and more I look in to it, the more likely i think it's amp glow. I tried taking darks during the night and I seem to be having the same issue. I wonder if it could be a power supply issue. I'm currently powering it using the deep cycle battery but I can try the AC adapter and report back.

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Tony
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Old 20-09-2018, 10:10 AM
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contacted qhy and they said it looks like potential light leak not amp glow. THE PLOT THICKENS
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Old 20-09-2018, 11:52 AM
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UPDATE: I've put the camera in a black container box and took darks. It looks like theres definitely light leak somewhere in the imaging chain. I've also been having trouble taking flats for the same reason.
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Old 24-09-2018, 09:35 AM
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I found the source of the light leak. Theres a small gap between the carousel and the m42 slot that allows in stray light when shooting in narrowband. This seems like a huge design flaw with the zwo mini efw. But I suppose these were designed for the ZWO cameras that MAY sit flush against the sensor window and mitigates the gap but the QHY sensor distance is a bit different and theres a gap between the window and the filter. ALSO, all those empty screw holes might also be contributing to the light leak as well. I think I might return this to bintel, sell the 1.25" filters and just use my QHYCFW 2" fw. :/

If anyone has dealt with this issue with the ZWO miniEFW and how to "fill" the gap and found a solution, that'd be fantastic as I'm not sure if bintel accept returns of this nature.

Thanks,
Tony
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