# Green / Purple Tint in the sky



## grbba (Nov 19, 2012)

Hello,

this is my first post on the forum and i submit an issue i am struggling with a long time now. In the attached picture in the sky in the upper left corner in the darker areas of the clouds you can see an greenish / purple tint which i never ever managed to get rid of or ease it at least. 
I tried many things but to no avail and i searched on the internet but it seems that i am to du... to find anything on this issue. 
I have this issue on several other pictures and actually if somebody cold explain what actually happens so i may correct this when i take the picture in the first place 

Any help would be appreciated a lot! 

//
grbba


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## Victoria Bampton (Nov 20, 2012)

Hi grbba, welcome to the forum!

Yes, I can see what you mean.  Is this happening with raw photos or JPEGs?  It might help to take a look at the original.


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## Jimmsp (Nov 20, 2012)

I've looked at this on two different monitors, and I struggle to see it. I might have convinced myself I see it now, but I'd like to look at more than a thumbnail. As Victoria suggested, could you post an original?


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## johnbeardy (Nov 20, 2012)

I've seen this occasionally too, and I think I've always eliminated it by very slightly tweaking the WB. I suspect it's more of a display problem as I've not seen it on a print.

John


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## grbba (Nov 20, 2012)

Hello, 

thanks for the replies. I added some links to original raw files in which
you should be able to observe the issue. In some its more pronounced in some less.

As additional information  I am on LR4.1 used on an HP LP2475w Monitor calibrated using Argyll, DispCal and a Pantone One sensor 
on a big set of patches so I should have pretty much all of AdobeRGB properly displayed. My DeltaE values are all in an acceptable 
range following the calibration validation performed within DispCal. ( But maybe something is here which i missed ?? )

I can see it also on not calibrated monitors ( incl. iMAC 27" and W7 HP 13" Laptop ) 

https://www.dropbox.com/s/1al6cz3sgikywel/_DSC2343.NEF
https://www.dropbox.com/s/el3xi12yge4dn8o/_DSC2518.NEF
https://www.dropbox.com/s/1pscyf1pcm1wj3x/_DSC2522.NEF
https://www.dropbox.com/s/3fy4n4tk638195l/_DSC2540.NEF
https://www.dropbox.com/s/qpy6u9n6wgrsdq1/_DSC2291.NEF

Hopefully you can download them from there as they are a bit bigger  and see also the issue.
The links will be available for 48hrs.

Thanks a lot 

//
grbba


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## Jimmsp (Nov 20, 2012)

I just stuck them in my dropbox. I'll look at them later tonight; and I'll probably try another converter as well.
Jim


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## Jimmsp (Nov 21, 2012)

I will look more later, but my first observation tells me this is not a Lightroom problem. I have converted these raw shots with both Lightroom 4.3rc and Capture One Pro 7. I used the "as shot" white balance in both. I can see the purple green areas you describe, and I also see some pinkish/red areas as well. Both converters see about the same thing. I can reduce the tinted areas in Lightroom a bit by implementing the lens correction for your lens as read by LR. This reduces the tint, but does not eliminate it.
My preliminary conclusion - it is from your lens. Next time, try to shoot a similar cloud area, but center it in the lens as well as on the edge. If the centered shot shows less tint we would know it is your lens.

Edit - When I reduce the exposure quite a bit, ~1.5 , the "tinted" areas are easy to see. I'm even able to see one near the center of one of the photos, and they don;t disappear even with a reasonable white balance. I still believe this is a lens effect.

Jim


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## clee01l (Nov 21, 2012)

Gregor, I agree with Jim.  This is not a LR issue.  Most likely it is a Lens issue.  Since the lens is not recognized in my LR4, I suspect a cheaper third party Lens.  I opened the images in LR (imported), ViewNX and the Preview App.  All showed the same red and green blotchy clouds in the corners.  

I get the best results using the Adobe Camera Standard Camera Calibration profile or Camera Neutral.  Also by playing around with the Camera Calibration  panel sliders, I can clean up much of the color distortion


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## grbba (Nov 21, 2012)

Hello,

thanks for looking at the pics  and digging into the issue.

The lens used is an old  NIKON 24-120 AF-D ("Streetsweeper") lens on a D700. If i activate profile and put Nikon as manufacturer LR uses the current version of the lens ( not the latest constant f/4 version ) but yes there is no automatic recognition. 

I never expected this being an LR issue anyway and more an issue with the camera/lens and/or my photographic knowledge/capabilities so i agree totally with your analyisis. I just tried to see how i can reduce the issue in the development module if possible. I will look into the camera callibration tonight and see if i can get some results as suggested and come back. 

I'd like to understand what circumstances and why this is happening. E.g. chromatic aberation i understand where it comes from and what circumstances make it happen and this issue looks also a bit like it but doesn't correspond to the reasons why you'd get the colored fringes or in this case colored swatches ..

It's not a systematic issue in the same part of the pics ( which imediatley would point to an lens/camera issue ). I would think its a optical phenomen induced by the lens and/or sensor which i can possibly control so some extent through exposure settings just as chromatic abberation. If i don't get why it's happening i will always do guessing when shooting and not get any consistent results. I will try to investigate further on this one ( maybe i have to take some physics classes on optics  ) and try to do what was suggested to reproduce the effect on different areas of the pic as suggested.

Do you know if there are any calibration profiles for the D700 ? or do the D2x one's have a corrspondence to settings in any
Nikon body somehow ?

Thanks a lot for your comments.

//

Gregor


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## Jimmsp (Nov 21, 2012)

I am not sure what it really is, though I can see some tint changes throughout most photos in the regions of the clouds. The biggest issues seem to be in areas where there is a dark to light transition. The best I can do to eliminate the large on in #2291 is to use a local area adjustment in Capture One where I can also change the tint and saturation of the selected color.  I don't think this is worth your time or investment.

I'd recommend two things.
First , rent a newer lens and take it out and shoot some comparison shots on clouds like this. This will verify the lens is the issue, and not the detector/sensor.
Second, save up for a newer lens. You can get some pretty good used lens at decent prices.

Good luck,

Jim


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## grbba (Nov 21, 2012)

Thanks Jim,

i will try out some shots with other lenses and see what i come up with this weekend. 
Indeed i will look into buying a more recent lens, i just have to make up my mind what i should 
get .... i like the range of the 24 120 but the latest one from Nikon is out of reach moneywise at the moment 
and the model before doesn't seem to be that good..
In any case i keep you updated with results.
And for the affected pics i just may recyle them in B&W 

//
Gregor


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