DaveC426913
Valued Senior Member
And would have motion blur.On the contrary. A fast enough moving object would show up in only one frame
Odd that this does not then.
And would have motion blur.On the contrary. A fast enough moving object would show up in only one frame
And would have motion blur.
Odd that this does not then.
You have not though that through.Not necessarily. I could post photos of any number of flying craft that aren't blurry.
Does anyone know what the camera shutter-speed was for those photos?How is it possible to transit the field-of-view in the one frame, yet not be blurry in that one frame? There's some math to be done there.
Of course, even if one would expect more motion-blur than is present, it could have stopped at the precise moment so as to photo-bomb the image, and then flown off again
That was where I was going originally. My earlier post that I removed was all about required shutter speed. I had calculated 1/265th, which was eminently reasonable,Does anyone know what the camera shutter-speed was for those photos?
If one assumes something like 1/200 seconds or 1/400 seconds, something like that, how far would the phenomenon have moved during the exposure time?
E.g. if the calculation is that the phenomenon, due to not appearing in either of the previous or next image, must have had a speed of 2,000 mph (taken from your quoted line above) then over 1/200th to 1/400th of a second you'd expect it to move somewhere between 4.5 and 2.5 metres during the exposure time. Would that be enough to create a blur on the image? (Note: I'm not a photographer, so the example exposure times I've used could be wide of the mark, but I'm imagining that the exposure times for aerial photography would be quite short, possibly even quicker than 1/400th, to get the sharpest shots. So take this purely as an example of something to consider). So maybe there wouldn't be any noticeable distortion from an object moving at that speed?
Of course, even if one would expect more motion-blur than is present, it could have stopped at the precise moment so as to photo-bomb the image, and then flown off again.
Of course there's no conclusion forthcoming.So what is your conclusion Dave? Is the object in the photo real or is it a camera artifact per James?
I initially thought it might be a helicopter, with it possibly disappearing under cloud in other pictures. But then I don't know what a helicopter looks like from above when photographed like that: would the individual blades be more visible? Would it even look anything remotely like the image taken?Of course there's no conclusion forthcoming.
Who says it's a metallic disc? Apart from you, obviously.And what kind of anomaly presents as a metallic disc?
At any useful shutter speed, helicopter blades don't rotate (225-500RPM) nearly fast enough to be blurred into a disc.I initially thought it might be a helicopter, with it possibly disappearing under cloud in other pictures. But then I don't know what a helicopter looks like from above when photographed like that: would the individual blades be more visible? Would it even look anything remotely like the image taken?
I did try and find a comparison, but none of a helicopted from 1 or 2km above, where the heli is not the focus of the shot, so wasn't sure if that would affect the image. I don't imagine it will particularly, to be honest. But "heli" was my first thought.At any useful shutter speed, helicopter blades don't rotate (225-500RPM) nearly fast enough to be blurred into a disc.
And even if they did, the body of the craft would not be obscured by it.
This is the worst case I could find in a quick Google search:
As usual, you have nothing beyond "it looks like a metallic disc to me"