Newbie needing help--image artifacts?

Discussion in 'Digital SLR' started by Iguana, Mar 21, 2005.

  1. Iguana

    Iguana Guest

    Hello all. I should first post some disclaimers: I'm new to digital
    photography, so I'm not very familiar with a lot of things (trying to
    learn though!) I had a film SLR many many years ago that I did some
    hobbyist photography.

    Trying to pick up hobby photography again, I purchased my first digital,
    a Nikon D70 (kit with lens) today. Went out and took a few lousy
    pictures just to get a feel for basics--used the camera on all auto
    settings as recommended in the quick-start guide (saved in JPG, large
    photo save, ISO200, etc). I'm saving learning what the more advanced
    features do until later.

    I noticed when I copied the files to my computer later, that 2 of them
    that contain a lot of sky have some gray dots, in the same places. A
    3rd image containing the sky, taken between these 2, does not have the
    same dots--but this middle image was not zoomed in as much. Is this
    perhaps the dust on the CCD that I've read about? I hope someone can
    help me with what it is--I just bought the camera today, and was careful
    about attaching the lens (I attached it indoors to avoid dust and

    Here is a link to the photos in question (yeah they are lousy, forgive

    The center photograph does not contain the dots, but the two end ones

    Also, what is recommended with a brand-new camera to do about the dots?
    If it is dust, is it easiest to use the small blower-bulb to clean it,
    or should I take it somewhere/swap the camera, since it is new?

    Again, sorry for the newbie question.

    Iguana, Mar 21, 2005
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  2. They could be dust. How badly dust shows up depends on the aperture
    you shoot at, among other things. Check the EXIF data (or your
    memory, if reliable) for what aperture the three photos were shot at;
    if the middle one was a wider aperture that may explain the

    The dot position in the first photo matches one of the dots in the
    third, and the others might be there hidden among branches -- I
    didn't superimpose them to check really carefully.

    Or shoot a small-aperture shot of the sky (or some bright even field)
    so the sky is a couple of stops brighter than mid-grey, and check
    *that* for dust. You'll nearly inevitably find *some*; you may find
    the same pieces in their same positions, which would be definitive.
    You want to do this before you clean the sensor, anyway, so you can
    tell how much good you did.
    You might as well learn to clean the sensor, is my opinion. I found a
    blower-bulb completely useless, and had to go to a suitable swab
    (PEC-pads or equivalent grade) with Eclipse cleaning fluid to actually
    get the dust off mine. But a blower bulb is harmless short of clumsy
    handling, so no reason not to try. You're going to be cleaning it
    every 6 months to a week, depending on the conditions you work in, how
    much you use it, and what kind of pictures you take (some kinds of
    work won't show up the dust nearly as much).
    No problem. Sensible reasonable question backed up with actual images
    of what you asking complaining about; this is *not* something people
    here will complain much about!
    David Dyer-Bennet, Mar 21, 2005
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  3. Iguana

    Sheldon Guest

    Decent advice, but I'd start with a "large" blower bulb. The manual will
    tell you how to lock up the mirror to get to the image sensor. Hold the
    camera with the image sensor facing somewhat down, and give it a few blasts
    with the blower. If you work with the image sensor straight up you may just
    move the dust around, so let gravity give you a hand.. Be careful not to
    touch the sensor with the end of the blower. If you are still having
    problems give it one more try and then you will probably have to actually
    swab or brush the sensor.

    This problem comes up a lot here, and you have to make up your mind whether
    one of those special brushes (don't use any old brush), or a pec pad and
    some cleaning liquid are best for you. You can send it to Nikon, but word
    is that it may pick up a few spots on the way back, and the charges will
    begin to add up if you send it to Nikon every time you get some dust on the
    sensor. Also, Nikon Capture can get rid of the dust for you via software.
    It doesn't remove the dust, but it covers it up on the image.

    Welcome to the world of DSLR's.
    Sheldon, Mar 21, 2005
  4. Iguana

    Diane Wilson Guest

    As another new D70 owner, I can tell you that the "auto" mode is
    purely a point-and-shoot almost idiot-proof setting, but without
    a lot of flexibility. The "P" setting is also full auto-focus and
    auto-exposure, but gives you all the flexibility in metering,
    exposure control, etc. I suggest that you change from Auto to "P"
    as soon as you start exploring the rest of the features of the

    You may also find that the auto white balance is something you
    want to turn off. Sometimes it does very good things, but sometimes,
    if your subject has a limited range of color, the auto white balance
    won't give you accurate color. If you want the predictability of
    film, in terms of color balance, try the fixed white balance
    David's advice on sensor cleaning is good. There have been recent
    discussions on dust on sensors recently, so you might want to Google
    for those.

    Diane Wilson, Mar 21, 2005
  5. Iguana

    Stacey Guest

    And is shot as a vertical so the dots would be mixed in with the tree limbs.
    Given all three were shot at very close to the same fstop (around F11) this
    is probably dust or else a problem with the cameras sensor.

    Doesn't matter, seems many come with dust on the sensor from the factory?

    Might as well get used to cleaning it as this will be something you'll have
    to deal with. Maybe if you never change the lens it won't happen again? I
    still don't understand why most manufactures are ignoring this as being a
    Stacey, Mar 21, 2005
  6. Iguana

    Iguana Guest


    Thanks to all the advice so far. I'll definately be heading out to a pick
    up a blower-bulb. I saw a few people in the "CCD dust poll" thread (can't
    remember exact name of thread offhand, but it is fairly current) say that
    their cameras came out of box with a bit of dust, so it doesn't seem
    necessarily uncommon.

    Iguana, Mar 21, 2005
  7. Iguana

    C J Campbell Guest

    It is dust. You can try a blower bulb, but the blower bulb is as likely to
    blow dust onto your sensor as off it. There are two other methods:

    The Copper Hill method, described by David:

    and using a special brush:

    The brush method is less intrusive and probably better. If these methods do
    not remove the dust, you will have to send the camera in for professional
    cleaning. Any other method will almost certainly introduce more dust than it
    removes, leave a residue on your sensor, or scratch the sensor.

    Another option is to simply ignore the dust and use the Healing Brush or
    Clone Stamp in a photo editing program to get rid of it, or use Nikon
    Capture and a dust reference photo to remove dust. Dust only shows up
    against bright or solid color backgrounds like sky, so you will not see dust
    if it is obscured by something else.
    C J Campbell, Mar 21, 2005
  8. Iguana

    Ed Ruf Guest

    It's even worse than that. In the Auto mode there is all sorts of in camera
    processing performed to the image which are dependent upon image content
    for their settings,

    From p. 32 of the manual:
    Use for snapshots. Camera settings are automatically adjusted
    according to subject and lighting, producing vivid, smooth
    images with balanced saturation, color, and sharpness.

    and from p56:

    At settings other than Custom:
    • Photographs are optimized for current shooting conditions. Results will
    vary with exposure and the position of the subject in the frame, even in
    scenes of the same type. To take a series of photographs with identical
    image optimization, choose Custom and adjust settings individually, being
    sure not to select Auto for Sharpening or Tone comp.

    IMO, you're best served to quickly begin using P mode after setting the
    Optimize Image function to Custom and explicitly setting all the settings,
    Sharpening, Tone Comp, Saturation to Normal. This gives a fixed amount of
    processing to every image. As you learn what the setting do you can change
    them. But if you leave it in full Auto mode the processing is inconsistent,
    so you'll have a hard time learning what each setting does.
    Ed Ruf, Mar 21, 2005
  9. Iguana

    Alan Browne Guest

    Ya got dust. Don't panic.
    If the aperture was open, you won't see the dust spots easilly (or at
    all). If the aperture was closed down (f/16 .. f/22 ...) then you're
    likely to see dust against a bright background).
    Throw it aside with great force.
    If you can get away with it, sure, but you might as well learn to clean it.
    Well, you can google this group for the 300 methods to clean dust from
    the sensor.

    Alan Browne, Mar 21, 2005
  10. Iguana

    Iguana Guest

    Thanks again for the help. It looks like I'll be off into dust-cleaning

    I did read a lot of references to dust, and how to clean it, etc, my
    problem was just that I couldn't find what dust spots looked like. When
    googling, most the time I saw a forum/news post with a link to a "dust"
    picture, it was an old post with a dead link :(

    But you guys know how to identify dust better than I can, and I appreciate
    the help.

    Iguana, Mar 21, 2005
  11. Iguana

    JPS Guest

    In message <>,
    I doubt that. I think that the fast blast makes it very difficult for
    new dust to attach itself to the sensor. Most dust that sticks to the
    sensor arrives slowly, and sticks because of static electricity. I have
    *never* failed to decrease the amount of dust with my blower bulb (it is
    a bulb intended for sucking solder).
    JPS, Mar 21, 2005
  12. Iguana

    Ed Ruf Guest

    I'm beginning to wonder if there might be a cleanliness issue with new
    D70s. The shots at
    were taken the first weekend I owned mine. Just look at any of the shots
    with blue sky between 10 and 11 o'clock.
    Ed Ruf, Mar 21, 2005
  13. I made many attempts with a blower bulb before I broke down and bought
    a pack of swabs and some Eclipse. The blower consistently just moved
    the dust around. The swabs take most of it off.
    David Dyer-Bennet, Mar 22, 2005
  14. Iguana

    JPS Guest

    In message <>,
    Did you face the opening of the camera down, and allow the dust to
    settle to the floor? Did you fill the bulb away from the action,
    slowly, and opening-down? Did you squeeze forcibly? There are many
    ways to use a blower bulb.
    JPS, Mar 22, 2005
  15. Iguana

    Bob Guest

    My new D70 had 3 dust spots - I returned it to the store for another one... the
    first photo I took had the spots, I printed it and took it back with the camera.
    I imagine someone in the store played with it quite a bit before I bought it.
    Other stores I've been to have a policy of never removing the lens of DSLRs that
    are new in the box - that's what demo models are for.

    I've had this one for 1 year and it just has a few tiny ones, not really
    noticeable. I rarely change the lens...
    Bob, Mar 22, 2005
  16. Iguana

    Bob Guest

    Holy cow that's not a dust spot - there's a spider living in your camera!!

    Nice pics otherwize...
    Bob, Mar 22, 2005
  17. Yes, yes, and yes.
    David Dyer-Bennet, Mar 22, 2005
  18. Iguana

    C J Campbell Guest

    There seems to be a cleanliness issue with new DSLRs of any brand. They all
    seem to have at least one dust spot right out of the box.
    C J Campbell, Mar 22, 2005
  19. Iguana

    Ken Ellis Guest

    They don't come with lens attached and i'm wondering if the new user
    is mindful of how easy it is to get dust in them...either airborn or
    from the lens.


    Ken Ellis, Mar 22, 2005
  20. Iguana

    Ed Ruf Guest

    If you look at the link I posted this is NOT dust. It is a circular ring
    shaped foreign object that was visible with the naked eye. Almost looked
    like plastic turnings, or thread shaving from a tap. In any case they were
    obviously black.
    Ed Ruf, Mar 22, 2005
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