Pink Highlights when shooting in UniWB

Discussion in 'Digital Photography' started by LumbermanSVO, Apr 14, 2012.

  1. LumbermanSVO macrumors 65816

    Joined:
    Mar 15, 2007
    Location:
    Denton, TX
    #1
    Over the last week I have been toying with UniWB(Canon T2i, aRGB, custom WB of a pure white frame, picture style set to 0,-4,-4,0) and ETTR and I'm getting mixed results.

    My biggest problem is that sometimes clipped highlight aren't showing up as "blinkies" on the camera, or they are too small to notice, and the histogram often still shows some room to the right.

    When I bring the picture into Aperture(latest version) and start to pull the exposure back down, the clipped highlights turn pink. I can't seem to find any way to fix the pink highlights and a couple hours on google didn't help. Has anyone had this problem before?

    Also, an odd thing that happened when I setup the camera for UniWB, the file names changes from "IMG_0000.CR2" to "_MG_0000.CR2" is this normal?

    This is a sample image, the only edit I made were changing the WB to the Daylight preset in Aperture and bringing down the exposure by 1 stop. If I bring down the exposure anymore the pink REALLY become apparent in the road stripes, big sign, window sticker and white cars.

    [​IMG]
    (Yes, I was stopped when I took the picture)
     
  2. acearchie macrumors 68040

    acearchie

    Joined:
    Jan 15, 2006
    #2
    Never had this problem before but have you tried shifting the WB shift in aperture towards the green and away from the magenta?

    Since you say that the pink ares were clipped was this just taken as an example image is is there a reason that it wasn't exposed properly when taken?
     
  3. LumbermanSVO thread starter macrumors 65816

    Joined:
    Mar 15, 2007
    Location:
    Denton, TX
    #3
    If I shift the WB away from the green then I just get a green tinted image with a bunch of pink highlights.

    Two things about the clipped part of this image:
    1) Part of the idea behind UniWB is being able to expose as far to the right as possible and have the jpg preview/histogram give you an accurate measurement of when the RAW file is clipping. Then you bring the exposure back down in post and get better details in the lower mid-tones and lower, this is an example if it working properly.
    2) I do some shooting at night in the city and often have light sources in the image. It is impossible to do these shots without having at least some clipping, but as long as the clipping is in places where it doesn't matter then everything is A-OK. If my highlights turn pink when pushing them around in post, then this is a serious problem.

    I sent a couple test RAW files(that have this issue) off to a couple friends who have LR4 and they both reported back they there is no pink. I also tried the same files in DPP and didn't get any pink. So clearly, this is an Aperture issue. This made my decision to switch to LR4 much easier and I have already placed the order.
     
  4. TheDrift- macrumors 6502a

    TheDrift-

    Joined:
    Mar 8, 2010
    #4
    Have you tried another program e.g. Lightroom or phtotoshop...you could try the free trail in lightroom and see if you get the same problem?

    That would at least tie it down to camera or post..my initial thought was maybe that your highlights have red in them anyway?

    The problem seems to be worst around the red car, is the white reflecting some of this red, and when its recovered its exaggerating it? If this is the case its more of a PITA then if the whole image was tinted..

    ...if the whole image is tinted then you would just need to adjust the white balance globally, if its only in parts of the images you need to adjust those parts only, and the effect will need fading in and out to match...

    It also looks like you have tried to remove some of the red in the image, (WB adjustment???) but it seems to be attacking the images as a whole rather than just the highlights where the problem is.

    My guess would be the white is picking up reflected red...I assume there was maybe something big and red behind the white car?
     
  5. LumbermanSVO thread starter macrumors 65816

    Joined:
    Mar 15, 2007
    Location:
    Denton, TX
    #5
    I sent a test image off to a couple friends, one with LR3 and one with LR4, both reported back with no pink, so this is an Aperture thing. I narrowed it down to the in-camera custom WB setting that Aperture doesn't like for some reason. I tried it in Canon DPP and had no problems.

    There was no red behind the car, it also happens in other pictures with no red in/near the scene. It's just something about the custom WB that Aperture doesn't like.

    I have ordered Lightroom 4, while I was at it I also ordered the Photoshop/Premier Elements bundle. :D
     
  6. LumbermanSVO thread starter macrumors 65816

    Joined:
    Mar 15, 2007
    Location:
    Denton, TX
    #6
    I wanted to add that when Aperture plays well with the UniWB + ETTR method, I'm pretty happy with the results. This is one where it worked as expected: http://forums.macrumors.com/showpost.php?p=14731832&postcount=226
     

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