Z8 and 180-600 lens unknown artifact in photo - possible cause?

[FastGlassGuy]

I took both of these shots this weekend at the Miramar Air Show in San Diego. I know they are not wildlife or landscapes, but I have a technical question regarding the one photo.

I shot both of the attached shots with a Z8 and 180-600 lens. The settings were as follows:
For shot without artifact - 300mm at 1/3,200 sec at f 6 at 20 fps (shot 1).
For shot with artifact - 180mm at 1/3,200 sec at f 5.6 at 20fps (shot 2).

I am not sure why there is a straight line on the rainbow vapor shroud on shot 2. I guess it could be some kind of a shadow effect, but it looks too straight and out of place to be a natural phenomenon, but I don’t know what else would cause this effect. It is clearly not in shot 1.

It is my understanding that the Z8 should not exhibit any rolling shutter artifacts, since it is shutterless and I was shooting stills at 20 fps and not video.

If anyone has an explanation, I would be glad to know what it is. Thanks, Ken

 

[Steve]

Just a guess, but it looks like the light was from above and that area is in shadow. Maybe just something about the angle at that particular moment.

 

[FastGlassGuy]

Just a guess, but it looks like the light was from above and that area is in shadow. Maybe just something about the angle at that particular moment.

Steve: Thanks for your input. It could be that. It just seems odd to me that it is such a straight and well defined line. You don't think it is any kind of sensor or lens artifact? Thanks, Ken

 

[Steve]

Steve: Thanks for your input. It could be that. It just seems odd to me that it is such a straight and well defined line. You don't think it is any kind of sensor or lens artifact? Thanks, Ken

Doesn't look like it to me. I kind of think it's the tail or wing blocking the light and not illuminating the vapor. A sensor issue would likely show up more as missing information - just random colors for instance. In this case, it looks like normal sky behind it and just a darker area along the edge between light and dark.

 

[FastGlassGuy]

Thanks Steve. Always reassuring when the experts weigh in, and it's not a problem. Ken

 

[soundbyte]

There is also a similar straight line coming from the rear edge of the closest wing, not as distinct though.

 

[ajrmd]

Agree, at first it doesn’t seem natural.. When I look at the image, it appears to demonstrate slight motion blur. One would suspect that the vapor trail would exhibit some blur rather than a straight line. If I had to speculate, the straight line is the result of shadowing from the wing edge rather than any sensor/lens error.

 

[Mark Garfinkel]

Agree, at first it doesn’t seem natural.. When I look at the image, it appears to demonstrate slight motion blur. One would suspect that the vapor trail would exhibit some blur rather than a straight line. If I had to speculate, the straight line is the result of shadowing from the wing edge rather than any sensor/lens error.

I would agree vapor trail, quite possibly exaust vapor from a jet in front of it. I'll look in my archives as I still my haver a simular photo.