Shape-Changing Light From Plane with Nikon P900 - Polarizing filter + Venus?

Ravi

Senior Member.
I am a little confused by the fact that there seems to be some kind a cut-out, or hole visible in the reflection. You see it in the first still of the video in the OP #1. I made a small gif to show it clearly. The green is the P900 aperture, yellow is the mysterious ring.

rings.gif

I don't think it is the plane window reflection of some kind, but what is that? Just a double reflection of the camera?

Edit: Is he holding a filter in front of the P900 perhaps?
 

DavidB66

Active Member
The description under the YouTube video explicitly describes the object as a star (Stern): 'Wir haben einen Stern aus dem Flugzeug heraus gefilmt ... Kamera : Nikon P900 Irgendwelche Ideen dazu ? ' Google Translate renders this as 'We filmed a star out of the plane ...Camera: Nikon P900
Any ideas on that?' , which seems accurate as far as my limited knowledge of German goes.

Can anyone explain how the background sky changes from a fairly light blue at the beginning of the video to nearly black at the end, in the course of about 7 minutes? The sky doesn't change that quickly at sunset. Is there a cut (or cuts) in the video? There are some clouds visible near the beginning, but not that dark. Also, if the 'object' is seen in front of a thick black cloud, that would pretty much rule out a star (or planet). A dark filter over the front of the camera (as suggested in #41) might explain it, but even if the photographer had a filter handy, why on earth would they use it?

My first thought, when I saw a short extract from the video in someone's Twitter post, was that the object looked very much like a large piece of plastic, maybe discarded wrapping material, blowing in the wind, but presumably that is ruled out by the length of the full video. A passenger plane would travel about 50 miles in 7 minutes, so an object drifting in the wind would soon be out of sight.

There might be more information in the related Facebook page.

Added: I found a post on the Facebook page, dated 8 June 2018. The video referred to is the 7 minute version, so the reference to 'best moments' does imply that this was edited to show 'highlights'. The full Facebook post says:
Wir haben die Nikon P900 während des Fluges auf einen Stern der am Himmel leuchtete gerichtet. Die besten Momente in dem Video.
Meinung dazu?
'''
We pointed the Nikon P900 during the flight at a star shining in the sky. Best moments in the video.
Opinion on this?
 
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Amber Robot

Active Member
The description under the YouTube video explicitly describes the object as a star (Stern): 'Wir haben einen Stern aus dem Flugzeug heraus gefilmt ... Kamera : Nikon P900 Irgendwelche Ideen dazu ? ' Google Translate renders this as 'We filmed a star out of the plane ...Camera: Nikon P900
Any ideas on that?' , which seems accurate as far as my limited knowledge of German goes.

Can anyone explain how the background sky changes from a fairly light blue at the beginning of the video to nearly black at the end, in the course of about 7 minutes? The sky doesn't change that quickly at sunset. Is there a cut (or cuts) in the video? There are some clouds visible near the beginning, but not that dark. Also, if the 'object' is seen in front of a thick black cloud, that would pretty much rule out a star (or planet). A dark filter over the front of the camera (as suggested in #41) might explain it, but even if the photographer had a filter handy, why on earth would they use it?

My first thought, when I saw a short extract from the video in someone's Twitter post, was that the object looked very much like a large piece of plastic, maybe discarded wrapping material, blowing in the wind, but presumably that is ruled out by the length of the full video. A passenger plane would travel about 50 miles in 7 minutes, so an object drifting in the wind would soon be out of sight.

There might be more information in the related Facebook page.

Added: I found a post on the Facebook page, dated 8 June 2018. The video referred to is the 7 minute version, so the reference to 'best moments' does imply that this was edited to show 'highlights'. The full Facebook post says:
It would be useful to know if it’s really a star or Venus. A star is a real point source but Venus is tens of arcseconds across and that could make a difference in interpreting what is seen in the context of an out of focus image.
 

LilWabbit

Active Member
But the patterns shown in the video seem far more stable than I would expect from atmospheric seeing, which should constantly be changing due to the random nature of the turbulence that causes it. What is Shown looks far more like the way an image might change as you change the aberrations due to focus shifts or changes in field position.

I note that I have no experience with using that camera and looking at stars or planets so I will defer to the experience of those of you have. I am just stating what it *looks* like to me.

There are different kinds of astronomical seeing, including the so-called 'slow seeing'. So much depends on the exact on-location atmospheric conditions, altitude and other factors. I'm only learning about it myself and it seems quite the complex. There's no one-size-fits-all "turbulence". For example the following sequence of double star Zeta Aquarii took as long as 2 minutes (pity there's no live footage available to illustrate):

flare_sequence_m.jpg

Having said that, I'm not convinced myself we're seeing only or even primarily atmospheric seeing in the OP footage. Of course some atmospheric effects are inevitable even in the OP footage (after all, the object's wavefront travels through the atmosphere into that Nikon) even if they do not account for the main features of the image. It's just to throw out there the various possible prosaic explanations.

You proposed the shape-shifting looks more like the changing aberrations resulting from focus shifts or field position changes. Is there footage to demonstrate the similarity of such effects to the OP footage?

The constant movement of the plane and high-altitude horizontal observation of a planet are factors to be taken into account. But difficult to replicate.
 

Amber Robot

Active Member
You proposed the shape-shifting looks more like the changing aberrations resulting from focus shifts or field position changes. Is there footage to demonstrate the similarity of such effects to the OP footage?
I don’t have any at hand. But my observation is based on personal experience trying to focus astronomical telescopes and in particular dealing with two that had pinched primary mirrors, resulting in astigmatism in one case and trefoil in the other.

the kinds of shapes seen here look like what I’ve seen. Can I know for sure? No. It’d be interesting to see if someone could replicate these kinds of shapes using the same or similar camera on a star.
 

LilWabbit

Active Member
I don’t have any at hand. But my observation is based on personal experience trying to focus astronomical telescopes and in particular dealing with two that had pinched primary mirrors, resulting in astigmatism in one case and trefoil in the other.

the kinds of shapes seen here look like what I’ve seen. Can I know for sure? No. It’d be interesting to see if someone could replicate these kinds of shapes using the same or similar camera on a star.

For me the shape is less of an issue than the shape-shifting since similar shapes occur both through atmospheric distortion as well as equipment-related distortions.
 

Amber Robot

Active Member
Having looked at the video some more I can see how those who suggested looking through a water droplet might be in to something. Optical aberrations have specific shapes and though there could be multiple aberrations present I can also see how this is what a star or planet could look like through a drop of water.
 

JMartJr

Senior Member
I am a little confused by the fact that there seems to be some kind a cut-out, or hole visible in the reflection. You see it in the first still of the video in the OP #1. I made a small gif to show it clearly. The green is the P900 aperture, yellow is the mysterious ring.

rings.gif

I don't think it is the plane window reflection of some kind, but what is that? Just a double reflection of the camera?

Edit: Is he holding a filter in front of the P900 perhaps?
Is it the reflection of the circular lens housing (is that the right word) of the camera, reflected in the window?
 

Mick West

Administrator
Staff member
I am a little confused by the fact that there seems to be some kind a cut-out, or hole visible in the reflection. You see it in the first still of the video in the OP #1. I made a small gif to show it clearly. The green is the P900 aperture, yellow is the mysterious ring.

rings.gif

I don't think it is the plane window reflection of some kind, but what is that? Just a double reflection of the camera?

Edit: Is he holding a filter in front of the P900 perhaps?
It's a double reflection. Where your arrowhead points are two reflections of the same finger. 2021-07-29_21-57-57.jpg
 

LilWabbit

Active Member
Can anyone explain how the background sky changes from a fairly light blue at the beginning of the video to nearly black at the end, in the course of about 7 minutes? The sky doesn't change that quickly at sunset.

It might if you're flying some 900 kph eastward during sunset.
 

LilWabbit

Active Member
Looking at the OP footage again.

***

Slow and steady shape-shifting through 0:18-0:38:

(1) The camera shakes and zooms more violently than the slow and steady shifting of shapes.

(2) The sharpness of the image seems to remain steady despite camera shaking and zooming.

Correct me if I'm wrong, but it would be very difficult to retain such steady sharpness during focus shifts. Also, assuming it's 'slow focus shifts' causing the 'slow shape-shifting', it would be very difficult for the camera to perform slow focus shifts during violent camera shakes and zooms and seamlessly continuing these shifts when the violent camera shakes and zooms suddenly stop.

Steady elongated Y-shaped pattern through 0:54-1:02:

(1) The elongated Y-shaped pattern remains quite stable despite the camera shaking and zooming.

(2) Here also the sharpness of the image does not seem to change despite the camera shaking and zooming.

Again, focus shifts would likely result in sharpness changes and be affected by the violent shakes and zooms by the camera and their sudden cessation.

***

In the first video shared by @MclachlanM (also shot by Nikon P900 from plane), the shape of the image is indeed very similar to the OP footage. Therefore, the model and make of camera equipment seems definitely to come into play in explaining the still refraction. However, the shape in his video doesn't change as demonstrated by comparing the zoomed image at 0:21 and at 1:04. This seems to rule out window/lens refraction, atmospheric refraction as well as the movement of the plane (alone or together) explaining the shape-shifting, and adding to the strangeness of the OP footage.

However, if the above process of elimination of focus shifts, window/lens refraction and atmospheric refraction withstands critique, the hypothesis of a dynamic refraction created by a droplet of water acting together with a constantly changing angle due to the movement of the plane gains in credence.

It could also be tested by someone with the right equipment and 'lab' conditions -- a point source of light, Nikon P900, water and a steadily changing camera angle.
 
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Amber Robot

Active Member
If you look back at the video in post 2, where the author of the video explains that he was adjusting manual focus you see similar shapes that only slowly vary with focus adjustment. The seeing causes a rapid flicker but does not impact the shape. Only the focus position does. In a plane you’d be above all the ground seeing.

I’m still more on the side of out of focus image than flying plasma creature
 

LilWabbit

Active Member
If you look back at the video in post 2, where the author of the video explains that he was adjusting manual focus you see similar shapes that only slowly vary with focus adjustment. The seeing causes a rapid flicker but does not impact the shape. Only the focus position does. In a plane you’d be above all the ground seeing.

I’m still more on the side of out of focus image than flying plasma creature

In my previous post I addressed why at this point it looks as if neither (focus shifts nor atmospheric refraction/astronomical seeing) are likely explanations for the OP footage shape-shifting. I may be wrong.
 
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Amber Robot

Active Member
In my previous post I addressed why at this point it looks as if neither (focus shifts nor atmospheric refraction/astronomical seeing) are likely explanations for the OP footage shape-shifting. I may be wrong.
You can correct me if I’m wrong but it seemed to me that you were assuming that the lens was on autofocus. If it were on manual focus I see no reason why a slow focus shift wouldn’t be possible despite not keeping the camera steady on the target. And at max zoom even a little bit of shake will look big. Given no more information than what is in the video I see no reason why the video couldn’t have been purposefully done out of focus this way to maximize the shape changing.
 

LilWabbit

Active Member
You can correct me if I’m wrong but it seemed to me that you were assuming that the lens was on autofocus. If it were on manual focus I see no reason why a slow focus shift wouldn’t be possible despite not keeping the camera steady on the target. And at max zoom even a little bit of shake will look big. Given no more information than what is in the video I see no reason why the video couldn’t have been purposefully done out of focus this way to maximize the shape changing.

Slow manual focus shifts could produce the effect if he's either playing around with the image or trying to sharpen the image at maximum zoom many times over and at a slower pace.

But I find it odd (as well as highly skillful) if during 0:18-0:38 he is manually slowly operating the focus while performing rapid zoom at the same time, only to seamlessly continue operating the focus right after stopping zooming. In other words, the image keeps slowly and steadily changing shape at the same time with the zooming as well as immediately after zooming.

Or then it's the autofocus trying and failing repetitively to sharpen a distant image, while unable to come out of the glitch even when zooming and shaking.
 
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Gary McH-P

Member
Perhaps we are assuming this guy actually knows how to operate the P900, when in fact he is a complete rank rookie and is messing around with the manual focus and does not really know what he’s doing, but hey! Some great effects!!
 

Shrinker

New Member
If I understand this correctly you’re looking for low-frequency action that could explain the slow shape shifting. The camera shake is high frequency, and the subject, if it’s Venus, wouldn’t be moving at all.

But if the plane is turning, the camera would have to slowly pan left or right across the window to keep Venus in frame, thus we’d be seeing Venus through a different part of the window, with subtly different optics over time. (I suspect at least one of the three layers of the window has some curvature.)

A less innocent variation is if the plane isn’t turning but the photographer is deliberately shifting side to side across the glass. I say deliberately because it’s hard to believe the phtographer wouldn’t know their movements were causing the shape shifting.
 

LilWabbit

Active Member
If I understand this correctly you’re looking for low-frequency action that could explain the slow shape shifting. The camera shake is high frequency, and the subject, if it’s Venus, wouldn’t be moving at all.

But if the plane is turning, the camera would have to slowly pan left or right across the window to keep Venus in frame, thus we’d be seeing Venus through a different part of the window, with subtly different optics over time. (I suspect at least one of the three layers of the window has some curvature.)

That's a real possibility in my opinion as well. However, in the first video posted by @MclachlanM (also from a plane) such shape-shifting does not occur. Maybe the plane in that video wasn't turning.
 
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