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08-29-2012, 12:16 AM   #1
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Purple fringing of K30 & DA*16-50

Not sure what happened...
on top the bus, u can see a crazy blur purple fringes, as a big area

wondering is the sensor problem or the lens
it was taken by K30 & DA*16-50 f2.8 as in F2.8 without turning the aberration correction....
would be good if any body could help to identify what was wrong

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08-29-2012, 12:34 AM   #2
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Wow that's subtle isn't it!
Almost looks like shadow clipping but I doubt that's the case given the exposure.
I don't suppose you have access to another K-30 to confirm this do you?
And what about repeatability?
Are you able to repeat this?
Is this phenomenon present in RAW or JPG format?

Last edited by JohnBee; 08-29-2012 at 01:26 AM.
08-29-2012, 01:06 AM   #3
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QuoteOriginally posted by JohnBee Quote
Wow that's subtle isn't it!
Almost looks like shadow clipping but I doubt that's the case given the exposure.
I don't suppose you have access to another K-30 to confirm this do you?
And what about repeatability?
Are you able to repeat this?
Is this phenomenon present in RAW of JPG format?
well in that night...there were more than 5 photos like that...
before it didnt happen at all...even there is...just minor purple fringing...
n nope i dont have change to try another K-30
i was try to do test in office...with office white lighting..
cant see much purple fringe too....
it was taken in RAW
08-29-2012, 03:16 AM   #4
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I think this has come up before. It's probably not a K30 issue, its a "neon light colour gamut" issue. The distracting flare from the filter indicates it could be a source of problem too.

For reference: check this thread

08-29-2012, 03:18 AM   #5
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Similar to Matt I was going to say could this possibly be an led light issue. But yes those deep violet neon lights are also tricky.
08-29-2012, 03:58 AM   #6
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Not sure what the cause is, in this particular photograph. But for what its worth, the 16-50 is one lens that I saw pretty obvious purple fringing. And many reviews note the fact.
08-29-2012, 04:01 AM   #7
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QuoteOriginally posted by palmerchan Quote
wondering is the sensor problem or the lens
So you are absolutely sure it is a problem.
..all right...
08-29-2012, 07:14 AM   #8
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See if you can replicate the same conditions with another lens if possible... My guess is that it's a light issue, not sensor or lens. LED lights do things like that—they're tricky to photograph!

08-29-2012, 07:21 AM   #9
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It is definitely LED/Neon lighting. They are very bright, and they have a very narrow band of light frequencies that tend to wreak havoc on all DSLR sensors.



See the light on the speaker - that's an example. There were a few other neon or LED lights washing over the band in the back, and I could not get a decent shot because of it. Wherever the light landed, it would be a bright, almost fluorescent shine on the subject.
08-29-2012, 07:55 AM   #10
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I've seen this with my 16-50 and K-5 to a larger extent than my other lenses; the problem I've had isn't just the blue color but the way it blooms quite strongly from strong light sources in high contrast situations. LED lights make it most problematic, but it also happens with chrome in sunlight and similarly challenging situations.

I've found applying local desaturation to be quite effective. If I had a more powerful photo program, I'd be desaturating just the blue channel. With the extreme blue coming from LED sources, this gives that part of the image the look of an uncoated lens without the overall loss of contrast that you would get from an actual uncoated lens--which I find very appealing. That would happen with JinDesu's image, for example. With palmerchan's image, though, local desaturation would simply make the building behind the bus appear white-ish, which is probably what your eyes saw in the scene.

Stopping the lens down also helps, and provides better stars from point light sources too.

Either way--it is a lens weakness, so if you can't work around it then you should exploit it.
08-29-2012, 07:43 PM   #11
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That is not purple fringing. It's the result of longer exposure and very saturated light source and improper color temperature balance. Any camera or lens will do pretty much the same thing. Setting the white balance before the shot or adjusting it in post should fix most of the problem. However, long exposures of colored light sources will create intense colors on your image.
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