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cornerfix

Discussion in 'Image Processing' started by Bimjo, Aug 7, 2012.

  1. Bimjo

    Bimjo Super Moderator

    Oct 28, 2011
    Washington State
    Jim
    I got my CV 15 yesterday afternoon. It's a lovely little lens, that unfortunately tends to vignette/color shift a bit on my 5N. Nothing I couldn't live with, and in fact, there will be shots that I don't correct because I want to convey a mood (be artistic & stuff). ;)

    Anyway, I downloaded a copy of cornerfix from soundforge and created a profile for the lens. Pretty straightforward, the key is getting a good image to use as the profile. It took me 4 tries until I got one that was useable. The directions are on the cornerfix site.

    Cornerfix works with DNG files, so if your camera doesn't save DNG files you have to convert them. I used the import conversion process in Bridge to convert my ARW files to DNG.

    This was the workflow for this pic.
    1) open lens profile in cornerfix
    2) open the converted DNG file (no processing yet at this point)
    3) save to file after cornerfix does its thing
    4) open the cornerfix "fixed" file in ACR, adjust to taste

    Then I applied the ACR setting to the original DNG file to show the difference between the two files.


    ***edit to add this pic***
    Here's one with a new cornerfix profile based on Dioptrick's suggestion from below.
    cornerfix_2.

    This is the first cornerfix file.
    cornerfix_y.

    And this is the original file, processed with the same settings as the cornerfix file.
    cornerfix_n.

    Rather dramatic difference. I'm still learning how to optimize the results in cornerfix. My profile still has a tiny bit of color shift in the upper corners that I need to resolve, but I'm impressed so far. Cornerfix works with any camera that can save a DNG file (or have its files converted to DNG), and with any lens, so it has broad application.
     
  2. Luiz Curcino

    Luiz Curcino TalkEmount Veteran

    265
    Apr 27, 2012
    Uberlandia-MG Brasil
    Hi bimjo, I also have a CV 15mm and use on the Nex. I have the same color shift a bit on my 5N. I'll try this Colorfix.
    Thanks for the tip.
     
  3. Dioptrick

    Dioptrick TalkEmount All-Pro

    Feb 4, 2012
    New Zealand
    Maybe take a photo of a plain blank wall with just one colour and no patterns, or a grey card, or maybe just a clean section of concrete path.

    You should be able to see the vignette pattern and colour-shift intensity more clearly without any distractions. It'll be easier to tell if your selected settings are under or over compensating.
     
  4. Bimjo

    Bimjo Super Moderator

    Oct 28, 2011
    Washington State
    Jim
    Yes, the hard part is keeping a shodow out of the frame. I'll have to rig some lights to do it properly, but this will have to work for a little while.
     
  5. Bimjo

    Bimjo Super Moderator

    Oct 28, 2011
    Washington State
    Jim
    Ok, I went back and shot another cornerfix profile pic and created a new profile. Applied to the original file and loaded it above. As you can see, the profile pic is critical to the final output.

    The beauty part is you can create/save multiple profiles for each lens, so you can process the pics differently depending on the scene/your mood/what day of the month it is… you get the idea. ;)
     
  6. Dioptrick

    Dioptrick TalkEmount All-Pro

    Feb 4, 2012
    New Zealand
    Looking good Bimjo...
     
  7. Bimjo

    Bimjo Super Moderator

    Oct 28, 2011
    Washington State
    Jim
    Thanks. I now have a greater appreciation for the lens corrections that Sony put in the camera. :)