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Unusual colour smudges in image

WoolybearWoolybear Member
edited July 2013 in general photography
I'm wondering if someone can clear something up for me? I have noticed on some (fortunately!) rare occasions some unusual 'smudges' in the RAW file. In this jpeg an example of this can be seen in the groom's jacket to the right edge of the frame.
I shot this using a Nikkor 70-200mm with an SB900 in a softbox on a stand to camera left, triggered by PW's on a D4.
I was shooting pretty much directly into the sun around 6pm on a sunny evening. I cannot expalin these marks, which is frustrating as I don't know how to avoid them..The lens and sensor was both clean.
Thanks for any help.
image

Comments

  • Did you use Liquid on the sensor?

    Lou Recine
    Matrix Photo
  • WoolybearWoolybear Member
    edited July 2013
    No there was no need for a wet clean just a squeeze of air .
  • May be check inside your lens for a big piece of dust
    Does it happen with your other lenses?

    Lou Recine
    Matrix Photo
  • are they always in the same location? Only when using a certain lens? Or all of them? Start to narrow it down so you can eliminate possible causes.

    rc
  • Good point! I'll look through the exif and see if other lenses are giving the same problem. Thanks for the idea
  • Looking through my files for the last couple of hours. I have noticed a large increase of photos with Moiré on the D4. When previously shooting with a D700, I had never noticed this. The extreme case of 'smudging' above is only limited to this wedding using the 70-200mm. Moiré is visible also in other RAW files on other lenses- the 24-70 and the 105mm Nikkor, not the 85mm however. The clothing seems to play an importance as does the lighting. Bounced flash has rarely given any signs whereas a softbox placed very close to subject has. I have just read that certain fabrics with the light falling from a particular angle coupled with a very sharp focus on the fabric can often give the problem of moiré. Playing around in LR5 and just re-installing Capture NX2 can deal with most moiré reasonably well as can the clone stamp tool and patch tool in CS6. It would, however be interesting to know what exactly is the combination that is doing this..
    Again visually examining my kit, the sensor is spotless and visually the lenses seem free of marks or dust. The smudges are only in 3 or 4 images and never in the same position. However it can be noted it is only visible on the groom's suit and on nobody else - I guess he bought a cheap suit! The moiré is a little more frequent even with other lenses.
    For the moment I guess I will have to live with it!
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