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Moonlit Contrail

ImageX PhotographyImageX Photography Registered Users Posts: 528 Major grins
edited December 20, 2013 in Other Cool Shots
I was wondering if anyone could help me explain what the perpendicular lines in the contrail might be..... when viewed at full size? Could it be from engine pulses or is it some kind of sensor/optical issue?


imx5560.jpg

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    ian408ian408 Administrators Posts: 21,913 moderator
    edited January 24, 2013
    Are you talking about the chevron shaped thing? More than likely, that's a reflection of the moon off of aircraft's skin.
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    ImageX PhotographyImageX Photography Registered Users Posts: 528 Major grins
    edited January 24, 2013
    ian408 wrote: »
    Are you talking about the chevron shaped thing? More than likely, that's a reflection of the moon off of aircraft's skin.


    If you view the pic at full size.... And look inside what I believe to be a contrail..... You can see many lines running perpendicular to the edges of the contrail. I think I'm seeing exhaust pulses from the engine but can't be sure.
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    ian408ian408 Administrators Posts: 21,913 moderator
    edited January 24, 2013
    ImageX Photography wrote: »
    If you view the pic at full size.... And look inside what I believe to be a contrail..... You can see many lines running perpendicular to the edges of the contrail. I think I'm seeing exhaust pulses from the engine but can't be sure.

    Let's call the red line the contrail-it's not really a contrail but the navigation lights of the jet. They blink and the line is created as the light falls off and some of it also reflects off of the aircraft skin. Jet engines don't pulse.
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    ImageX PhotographyImageX Photography Registered Users Posts: 528 Major grins
    edited January 24, 2013
    ian408 wrote: »
    Let's call the red line the contrail-it's not really a contrail but the navigation lights of the jet. They blink and the line is created as the light falls off and some of it also reflects off of the aircraft skin. Jet engines don't pulse.

    Huh? headscratch.gif Let's call the contrail the contrail. I know what the red lights are(and the secondary blinking light right below it). I am talking about the exhaust fumes..... or ever widening contrail due to long exposure. There is a pattern of many lines inside of it. See them?
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    ian408ian408 Administrators Posts: 21,913 moderator
    edited January 24, 2013
    ImageX Photography wrote: »
    Huh? headscratch.gif Let's call the contrail the contrail. I know what the red lights are(and the secondary blinking light right below it). I am talking about the exhaust fumes..... or ever widening contrail due to long exposure. There is a pattern of many lines inside of it. See them?

    I see the red navigation light and what you described as "exhaust fumes or ever widening contrail" looks to me like a chevron coming off the nav light and that looks like a reflection of moon light.
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    ImageX PhotographyImageX Photography Registered Users Posts: 528 Major grins
    edited January 24, 2013
    ian408 wrote: »
    Let's call the red line the contrail-it's not really a contrail but the navigation lights of the jet. They blink and the line is created as the light falls off and some of it also reflects off of the aircraft skin. Jet engines don't pulse.
    ian408 wrote: »
    I see the red navigation light and what you described as "exhaust fumes or ever widening contrail" looks to me like a chevron coming off the nav light and that looks like a reflection of moon light.

    Are you on a full screen pc? The lines are very visible when viewed at full size. I don't think that is a reflection though. It's way to big for a tiny flying dot in the sky..... even if it is widening due to long exposure. It looks like moonlight lighting up exhaust to me. Maybe someone else can chime in about what is going on here and what is up with the lines.

    imx55602.jpg
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    ian408ian408 Administrators Posts: 21,913 moderator
    edited January 24, 2013
    ImageX Photography wrote: »
    Are you on a full screen pc? The lines are very visible when viewed at full size. I don't think that is a reflection though. It's way to big for a tiny flying dot in the sky..... even if it is widening due to long exposure. It looks like moonlight lighting up exhaust to me. Maybe someone else can chime in about what is going on here and what is up with the lines.

    Nope. Laptop. But I enlarged the full size image. I don't see any perpendicular lines. Just what I described to you.
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    ian408ian408 Administrators Posts: 21,913 moderator
    edited January 24, 2013
    Might be better if you posted an enlargement of the section of the image you're talking about.
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    ImageX PhotographyImageX Photography Registered Users Posts: 528 Major grins
    edited January 24, 2013
    ian408 wrote: »
    Might be better if you posted an enlargement of the section of the image you're talking about.

    I did post a crop. Laptop screen should be big enough to see them. I'm looking on a netbook and Ipad and see them.
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    ian408ian408 Administrators Posts: 21,913 moderator
    edited January 24, 2013
    I still think reflected light.
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    ProxyProxy Registered Users Posts: 4 Beginner grinner
    edited December 20, 2013
    Google sent me here after looking for moon-lit contrail pics, but I'll add my thoughts.

    I don't see any contrail in the picture, so can we eliminate that as a factor?

    Here are my observations:

    1) Nav and strobe lights of the aircraft (red line and occasional white dots, respectively) are obviously visible, but a contrail is not.

    A contrail would extend along the same line directly behind the nav/strobe light trail. If it was very windy at altitude, the contrail could be very slightly offset, but not to the extent we're seeing below and to the right of the aircraft's path.

    2) I'm going to say the light area below the aircraft (not a contrail) is a reflection of the moon off of the aircraft, and the lines in the photo appear to be roughly at the same angle as the moonlight from the top right of the photo. With that, I would think the lines within the reflected light are caused by the rays of moonlight.
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