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Thread: CA issue with E-P1 and Lumix G Vario 7-14mm

  1. #1
    Member gDallasK's Avatar
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    CA issue with E-P1 and Lumix G Vario 7-14mm

    Here's a corner from an image I shot earlier today :



    Not very pretty is it? I'm far from impressed with this performance. I shot it as a Superfine Jpeg at 7mm f4.0. I know it was a pretty demanding shot - hard, dark edges against a very bright sky but - really - I get less CA than this with my wife's Sony P&S! I had read somewhere (can't remember where though) that the reason the Lumix 7-14 is so light is that CA and other optical imperfections are dealt with by software in camera. If this is the case than it seems that the Olympus doesn't understand how to translate "Panasonic". And I've just sold my G1 so can't check the lens out on that.

    And - annoyingly - I can't remove it with the CA tools in Lightroom or CS4. They have no effect on it at all.

    Is anybody else experiencing this problem? And if so, is there a solution - other than avoiding using the lens under such challenging conditions?
    Geoff
    Too many cameras, too little time.
    www.pbase.com/gDallasK

  2. #2
    Ranger 9
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    Re: CA issue with E-P1 and Lumix G Vario 7-14mm

    I'm not sure what you're seeing is "chromatic aberration" (a lens design fault characterized by light of different wavelengths being brought to focus at different points.) Color fringing is a symptom of chromatic aberration, but the symptom isn't the same as the "disease."

    I think what you're seeing may be "blooming," which is a sensor fault characterized by charge from bright areas bleeding into adjacent dark areas.

  3. #3
    Member gDallasK's Avatar
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    Re: Blooming?

    Quote Originally Posted by Ranger 9 View Post
    I think what you're seeing may be "blooming," which is a sensor fault characterized by charge from bright areas bleeding into adjacent dark areas.
    Would blooming be specific to a single camera / lens combination? I don't get it with any other lens and it disappears as I stop down beyond f8.
    Geoff
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    www.pbase.com/gDallasK

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    Senior Member Brian Mosley's Avatar
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    Re: CA issue with E-P1 and Lumix G Vario 7-14mm

    Hi Geoff,

    if you can shoot raw + jpeg and repeat the problem... try Capture One 4 or Bibble Pro version 5 (beta) and you may find they do better - but my first thought was also of sensor blooming.

    Kind Regards

    Brian

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    Subscriber Member Streetshooter's Avatar
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    Re: CA issue with E-P1 and Lumix G Vario 7-14mm

    There is a program I use that would fix the image but of course not the problem.
    It's called Epict or something and when I get back to the
    outer, I will post the link. It's the best $25.00 I ever spent.

    The image looks like blooming to me also....
    I think you would'nt see it out of the Panny.
    Don

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    Re: Blooming?

    Quote Originally Posted by gDallasK View Post
    Would blooming be specific to a single camera / lens combination? I don't get it with any other lens and it disappears as I stop down beyond f8.
    Yes, this is blooming.

    Blooming can be quite specific to a particular lens and sensor setup. I've had lenses (when I was working with Pentax gear) that worked fine on the 6Mpixel sensor of the *ist DS and bloomed a lot on the 10Mpixel sensor of the K10D, and vice versa. And yes, stopping down changes the interaction between lens and sensor; it can reduce blooming.

    What would be interesting is if you could take the same photo with a G1 as well.

    I would normally use an ultrawide like the 7-14 at f/5.6-f/8 anyway, and I always/only capture in RAW format. It's harder to correct this stuff with only JPEG image data.

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    Subscriber Member Streetshooter's Avatar
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    Re: CA issue with E-P1 and Lumix G Vario 7-14mm

    Here's the link for PTLens....
    it's $25.00 USD and well worth it...

    the trial lets you do 10 images for free...

    http://epaperpress.com/ptlens/

    shooter

    and NO! I don't get anything from them...just pure satisfaction....

  8. #8
    Member gDallasK's Avatar
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    Re: Blooming?

    Quote Originally Posted by Godfrey View Post
    What would be interesting is if you could take the same photo with a G1 as well.

    I would normally use an ultrawide like the 7-14 at f/5.6-f/8 anyway, and I always/only capture in RAW format. It's harder to correct this stuff with only JPEG image data.
    Hi Godfrey,

    The G1 and the 7-14 mm lens were simultaneously in my ownership for only about five minutes. Unfortunately the G1 has been despatched to a new owner now that I've jumped ship to the E-P1 so I can't do a comparison!

    I will be back to capturing exclusively in RAW just as soon as those nice people at Adobe get their act together and release a version of either ACR or Lightroom that will recognise the .ORF files. I've deleted the ironically named Olympus Master program from my computer, I'm afraid. It is possibly the most horrible item of software I've seen for many, many years and Olympus should be ashamed of themselves for releasing a product with such a crude user interface. That said, the E-P1 produces some very, very nice jpegs! Though obviously not the one in my original post ........

    Best regards.
    Geoff
    Too many cameras, too little time.
    www.pbase.com/gDallasK

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    Senior Member m3photo's Avatar
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    Re: CA Correction in CS4

    Quote Originally Posted by gDallasK View Post
    And - annoyingly - I can't remove it with the CA tools in Lightroom or CS4. They have no effect on it at all.
    Not to worry Geoff, there are plenty of ways to skin a cat. In Photoshop just make a rough selection of these areas and then go to Color Range in the Selection Menu. Click on the offending colour and Shift-click on any more you need to then Feather a couple of pixels. Un-saturate to taste, these previously purple areas will now be an inoffensive gray and at normal viewing ranges will pass off unnoticed.

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