What's causing banding?

[Sprocketdog23]

I noticed several images displaying a dark line of banding after using my Voigtlander 12mm lens on my R-D1. We have a pretty bright, low winter sun this month in the UK, and the line occurs when I'm photographing into bright skies (with the sun directly behind me). I've not seen this phenomena before with this lens, (maybe I've never used it under these conditions before), but unsure why its happening. Is it something to do with the way the sensor/lens combination is reacting to polarisation (not that the lens has any kind of filter attached). On different photo's the line is in a different position, but always is running top right to bottom left.

 

[Sprocketdog23]

another image with same diagonal line

another image with same diagonal line

Here is another image taken a few minutes earlier displaying same issue. It's occurred to me that the dark diagonal line is physically in the same place in it's actual location in the sky (I was about a hundred meters to the left of the first image I posted. Could the phenomena be EM interference? Those Power Lines nearby are pretty big. My other thought was some kind of jet trail shadow (maybe from the one to the right), but it was pretty cloudless day, and I really can't remember seeing a diagonal line at the time (I'm sure I would have noticed)

 

[Sprocketdog23]

Wow....Maybe this is the answer http://contrailscience.com/contrails-dark-lines-chemtrails/

It was a Volumetric Edge Shadow. Never ever photographed one before (even by accident 🙂

 

[Pherdinand]

good one, Sprocketdog 🙂

 

[V-12]

Here is another image taken a few minutes earlier displaying same issue. It's occurred to me that the dark diagonal line is physically in the same place in it's actual location in the sky

The line isn't in exactly the same place, there is a dust shadow in the sky near the line which is your datum point, and it shows the line has shifted a bit so your very interesting detective work could well be correct.

V

 

[Larry H-L]

I had this once on an architectural shoot using a Canon 5D Mk 1, turned out to be a hair from a blower brush... stuck in behind the lens, but not touching the sensor. It gave a soft-edged line in the sky.

Take your lens off and look in there carefully, mine was really tiny and difficult to see, but it was there. Pulled it out, line gone.

Good luck