Distortion correction - JPEG vs RAW

Discussion in 'Olympus Cameras' started by BlueDevil, Apr 21, 2015.

  1. BlueDevil

    BlueDevil Mu-43 Regular

    42
    Jul 8, 2013
    Australia
    With WA shots on my Olympus cameras when I look at the JPEG and RAW files of the same image there seems to be less lens distortion in the JPEG image eg straight horizon in JPEG vs slight curve in RAW, or poles near the edge of the photo in JPEG are straight but slightly curved in RAW .

    Why is this? Does the JPEG from the camera correct for lens distortion automatically?
     
  2. b_rubenstein

    b_rubenstein Mu-43 All-Pro

    Mar 20, 2012
    Melbourne, FL
    Yes. Along with chromatic aberrations and vignetting. (starting with the E-M1 and all the Olympus cameras since then)
     
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  3. BlueDevil

    BlueDevil Mu-43 Regular

    42
    Jul 8, 2013
    Australia
    Thanks for your reply.
     
  4. hazwing

    hazwing Mu-43 All-Pro

    Nov 25, 2012
    Australia
    Which program are you using? I think in lightroom distortion correction is in built, for raw files
     
  5. BlueDevil

    BlueDevil Mu-43 Regular

    42
    Jul 8, 2013
    Australia
    I'm just viewing them in Picasa at present and use a combination of Photoshop and Picasa for editing.

    My reason for posing the question is a little off stream. I mainly do underwater photography and find with a wide angle lens and a dome port that I am getting distortion in corners and edges of the JPEGs that isn't present in the RAW files. This seems counter intuitive because I would have expected the opposite (ie corner distortion would be corrected in the JPEGs but not in RAW).

    Maybe the JPEG software in the camera is applying a correction, but for some reason the glass dome port on the underwater housing is creating a distortion that it is misinterpreting.

    Here is a link to an example. If you flick backwards and forwards between the two images quickly the distortion of the diver in the left corner becomes quite obvious in the JPEG image.
    (Not my best photos by the way, but they are a good example for what I am talking about)

    https://picasaweb.go...CKemycSdo8LQBQ#
     
  6. Klorenzo

    Klorenzo Mu-43 All-Pro

    Mar 10, 2014
    Lorenzo
    One thing I do to rectify the 9mm BCL is to tell the program (Darktable) to correct it like it is another lens (Generic fisheye 10/12mm). This gives me the best results.
    You could try the same trick with Photoshop selecting a wrong lens. Otherwise you can create a custom correction profile.
     
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  7. BlueDevil

    BlueDevil Mu-43 Regular

    42
    Jul 8, 2013
    Australia
    That's an interesting idea - thanks. That is something I could play around with.

    Otherwise I will just have to improve my RAW processing skills in Photoshop so I can use the distortion free RAW images instead of the JPEGs
     
    Last edited: Apr 27, 2015
  8. stuntman

    stuntman M43 FOR THIRDS 4 EVER

    300
    Jul 6, 2011
    Connecticut
    ED
    I use the OLY software to save my raw as "RAW OR TIFF" and the jpgs as "JPGS". After that, I don't try to convert with any third party software. Nobody but Olympus has a handle on the true conversion. I have tried with CS6, picassa and a slew of others. They all have their own conversion spin on things. In the end ALL is not equal. I convert OLY raw to JPG and let the rest of the world figure it out from there. Just my 2 cents.
     
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  9. oldracer

    oldracer Mu-43 All-Pro

    Oct 1, 2010
    USA
    If you're going to invest the time to post-process your images, there are many reasons that you should start with the RAW file and not the JPG. In fact, if both are presend, Lightroom doesn't even let you work with the JPG.