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

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FastGlassGuy

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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
 

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  • SHOT 1 _DSC9540.jpg
    SHOT 1 _DSC9540.jpg
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  • SHOT 2 _DSC5618.jpg
    SHOT 2 _DSC5618.jpg
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Steve said:
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.
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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
 
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FastGlassGuy said:
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
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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.
 
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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.
 
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ajrmd said:
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.
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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.
 
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ajrmd said:
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.
Click to expand...
It could be some motion blur, but I was shooting at 1/3,200 of second. It was also really hazy because of all of the jet exhaust and there was probably some heat distortion as well. Ken
 
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GregT943 said:
I think it might be reflections and glare between the clear filter and your lens elements. This can happen if the angle of light is just right, and sometime presents as newtons rings or rainbow type glare.
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Greg: I am not sure, and I could be wrong about the halos, but I think that the rainbow effect in both shots is "real." There was condensation around the planes, and I think that the sun was in position to create a rainbow look just like it would in the atmosphere shining through clouds. My only question had to do with the weird discrete straight line that bisects the rainbow halo in shot 2.
 
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ajrmd said:
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.
Click to expand...
Thanks for your explanation. Ken
 
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Shadow from the wing. I shoot airshows several times a month with a Z9 and have only seen a slight issue that might be rolling shutter with a 80 hp LeRhone rotary @1/250 sec. This isn't that.
 
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FastGlassGuy said:
It could be some motion blur, but I was shooting at 1/3,200 of second. It was also really hazy because of all of the jet exhaust and there was probably some heat distortion as well. Ken
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Yes, I was looking at it on my cell phone and when I viewed it on my computer screen what I perceived as motion blur was clearly haze/atmospherics. I still stand by the explanation that the "line" was created by the hard shadow of the wing.
 
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Warren D said:
Shadow from the wing. I shoot airshows several times a month with a Z9 and have only seen a slight issue that might be rolling shutter with a 80 hp LeRhone rotary @1/250 sec. This isn't that.
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Thanks for the info. Just out of curiosity are you going to the Pacific Airshow in Huntington Beach, CA? I'll be there to tomorrow. Should be a good show. Ken
 
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Warren D said:
No, I'm on the east coast and will be at Old Rhinebeck Aerodrome for the next few weeks.
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Understood. I was not familiar with Old Rhinebeck Aerodrome so I looked it up online. Seems like an interesting place, with a lot of photographic opportunities. Have fun and good luck (photo wise). Ken
 
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Cameron T said:
I have to agree. Being able to see full res images would probably help as well, the extreme compression isn't doing us many favors.
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Cameron T: Sorry about the low res. As you know the forum restricts size to 1800 x 1200, and I don't have any account that I can link to for access to higher res shots. Ken
 
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FastGlassGuy said:
Understood. I was not familiar with Old Rhinebeck Aerodrome so I looked it up online. Seems like an interesting place, with a lot of photographic opportunities. Have fun and good luck (photo wise). Ken
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Thanks, and good luck to you. ORA is great this time of year with the lower sun angle. Sunday will likely be a south show (runway is n/s) so as long as the clouds hold off, it'll be good. I'm the staff photog there.....so I'm well acquainted with the photo-ops!
 
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This leaves me kind of baffled. It looks like condensation to me. The question is, whether the condensation is in the air or on your lens or sensor.
What I don't understand is that rhombohedral shape of the halos.
Nevertheless, I think that it's nothing to worry about, since condensation eventually disappears.
 
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