What are these artifacts, and how do I remove them?

Discussion in 'Digital Darkroom' started by crabseye, Nov 13, 2012.

  1. This exact phenomenon is occurring occasionally when I take photos. Look at the screen of the Nook. There are these darker blobs all over.
    1) can someone tell me what is causing them?
    2) what is the easiest way to remove them?
    Thanks so much for any help anyone can provide![​IMG]
     
  2. I assume it's not dust? It looks like there's no pattern and they are all different but relatively similar in
    size. Very interesting . . .
     
  3. I only notice it on some photos. I have no idea if it's dust? ... how to know for sure?
     
  4. Probably dust. Check whether they always appear in the same place and if they become more visible at smaller
    openings. If so it's time to clean the sensor.
     
  5. Have you checked your sensor for dust?
    You can do so by shooting a patch of clear sky at f22. Dust on your sensor will show up as blobs such as shown here.
    <Chas>
     
  6. Will do ... does it matter if the camera can't focus on the sky? Or should I focus on a cloud and recompose on blank sky?
    EDIT: Identical photo at f/11 (the one shown is f/18) shows no blobs.
     
  7. Identical photo at f/11 (the one shown is f/18) shows no blobs​
    That strongly suggests sensor dust, which is what it looks like to me anyway. You don't need the sky. This blank screen (http://www.pbase.com/copperhill/image/95174363/original) works just fine.

    There are lots and lots of postings about how to clean the sensor. I use a rocket blower first. If that does not work, I use a static brush, which you can get inexpensively from Copper Hill. If that also does not work, I do a wet cleaning using the Copper Hill method. The have detailed instructions on line.
     
  8. Thanks so much for all the responses. I've never had dust issues before, so I assumed it would be the random fleck here and there, not a case of freckles.
    Once in fog I took a photo with flash ... resulting in white blobs of varying sizes. This reminded me of that but obviously no indoor fog! lol
    I'll follow through with Dan M's suggestions.
     
  9. Besides cleaning the sensor, also look at the rear lens element surface. It might be dirty too. So, don't sneeze around your equipment. :)
     
  10. Ray House

    Ray House Ray House

    There have been some reports on DPReview with Nikon D80's showing a series of these dots grouped towards the center of the frame which could not be removed by conventional wet cleaning. My D80 started showing these spots after about 7K shots and maybe 5 wet cleanings. The spots were smaller than most dust specks and did not move or change with cleanings. To my knowledge the problem was never resolved by anyone experiencing it...I gave my D80 away due to this issue. I adjusted your image to enhance the spots. I hope a cleaning will resolve the issue for you...
    00b1kb-503953584.jpg
     
  11. That last image looks like oil splatter to me.
     
  12. Hmmm, where would oil come from?
    ___
    Didn't have the chance to try cleaning last night ... will probably try this weekend.

    Concerned that it is a model-related issue. Sure hope it's as simple as dust. Though I've always been extremely careful about keeping the lens off only a second or so when swapping.
    I'll have to check total number of frames shot. I doubt it's anywhere near that high. Is that info contained in a menu somewhere?
     
  13. There have been numerous reports over the years of batches of cameras being overloaded with the lubricant that keeps the shutter mechanism working, and this being sprayed all over the inside of the camera as it's used - and the more you shoot, the worse it gets.
    For example:
    http://www.fredmiranda.com/forum/topic/1105738
    http://nikonrumors.com/forum/topic.php?id=3653
    http://photocamel.com/forum/nikon-forum/162000-d7000-oil-splatter-sensor-cleanup.html
    http://forums.steves-digicams.com/nikon-dslr/191353-d7000-oil-sensor.html
    http://www.flickr.com/groups/d600nikon/discuss/72157631700055703/
    Many, many more such discussions out there if you search (say) 'Nikon "oil splatter" sensor'.
    Maybe the odd D80 fell foul of this too.
    I'm pleased to say that practically nothing comes up if you replace "Nikon" with "Canon" - but I would say that - I shoot Canon!
     
  14. Tried a blower, sensor brush, and Eclipse for about 15 minutes. Not a single spot changed, except I think I may have added some actual dust to the sensor.
    I've sent an email to Nikon, we'll see what happens with that.
     

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