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05-29-2010, 08:02 PM   #1
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Lens help: What's the anomaly here?

I know I should probably know this...but it's got me scratching my head.

Something weird's going on in the top (predominantly left hand-side) of this photo:



Does anyone know what the vertical banding is due to?

Some technical detail:
K20D with A35-105/3.5 @ 35mm
ISO100, f6.3, 1/4s

...it sort of looks like I shot this from behind a pane of glass and there's some ambient reflection, but this was an uninterrupted view.

Maybe it's just lens f/g-lare?

Really appreciate the help...

05-29-2010, 08:10 PM   #2
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Are you using any filters on the lens? Is the banding persistent in all of your shots?
05-29-2010, 08:19 PM   #3
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I knew I'd forget to mention something of note...

No filters and it seems to have disappeared with the very next shot....though this was zoomed in (~80mm) somewhat.
05-29-2010, 08:22 PM   #4
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Possible causes I can think of:
-damaged lens
-dirty front element
-reflections from a not-designed-for-digital lens
-the sky actually looked like that


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05-29-2010, 08:25 PM   #5
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So then does the banding only show up at certain focal lengths? ie @35mm?
05-29-2010, 08:28 PM   #6
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Hmmm...thanks Adam. I'd like to claim no.4, which would attract some of you guys to our grand little piece of the world Down Under....but sorry.

1?. Possibly but it seems fine with all other shots...
2?. Seems clean to me...
3?. This is where I'm leaning, as the only real catalyst here appears to be the 'bright' sky. Just seems a weird manifestation of glare.

....

Ah yes another piece of info I neglected to share. I'm shooting with no hood on the A35-105!
05-29-2010, 08:31 PM   #7
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QuoteOriginally posted by MrApollinax Quote
So then does the banding only show up at certain focal lengths? ie @35mm?
Not that I've noticed mate, just this one frame.

...though I can't vouch for the position of the light source in any other long shots.

Clipping the old zoom on as we speak to brave the cold and see if I can't duplicate the problem.
05-29-2010, 08:47 PM   #8
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If you can't reproduce it consistently then you might have just had a strange confluence of events that just happened to cause this.

05-29-2010, 09:36 PM   #9
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Thanks Mr Apollinax.

That's sort of what I'm hoping....on one hand. On the other it would be nice to identify the factors that led to the convergence so I can try to better control them - e.g., use of a lens hood when dealing with oblique light sources.

So here we have it folks, another of life's little mysteries
05-29-2010, 10:39 PM   #10
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QuoteOriginally posted by stillshunter Quote
Hmmm...thanks Adam. I'd like to claim no.4, which would attract some of you guys to our grand little piece of the world Down Under....but sorry.

1?. Possibly but it seems fine with all other shots...
2?. Seems clean to me...
3?. This is where I'm leaning, as the only real catalyst here appears to be the 'bright' sky. Just seems a weird manifestation of glare.

....

Ah yes another piece of info I neglected to share. I'm shooting with no hood on the A35-105!
What's the hood like? Metal or rubber? My 35-105 didn't come with one, and I decided not to use the generic round one that I thought would work with it

If you're using the original (I think) metal hood, then this might be some sort of reflection.

BTW, the "next shot" that you linked is fantastic! I'm a big fan of this lens- IMO it's among the best in its range.

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05-29-2010, 10:48 PM   #11
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Thanks for the feedback on the shot Adam. I'm growing pretty fond of this hefty piece of glass myself. It's a great range and although heavy it's old world solid - in that way that you really know something real is going on inside.

Sorry mate I've miscommunicated something along the line here. I did not shoot with the hood as, unfortunately, I don't own one. Actually I'd be curious at to what a native one looks like.

BTW: does a generic 67mm petal retro fit onto this? Is that what you were contemplating for your lens?
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