How 'bout this dust on the sensor thing?

Discussion in 'Digital SLR' started by Matt Clara, Jun 26, 2006.

  1. Matt Clara

    Matt Clara Guest

    How am I supposed to clean that off? And just to give a luddite rant, I
    never had that fecking problem with film! ;-)

    I've shot three weddings in the last three weeks, and they all have the same
    blurry patch on them, and I did lockup the mirror and used a bulb to attempt
    to dislodge it.
     
    Matt Clara, Jun 26, 2006
    #1
    1. Advertisements

  2. Matt Clara

    cjcampbell Guest

    The Copper Hill method works well. It is essentially the same method
    that the manufacturer would use if you sent it in to them. The warnings
    in your camera manual are greatly exaggerated, but then if you are a
    klutz and destroy your camera, well, it is because you are a klutz, not
    because there is anything wrong with the Copper Hill method. :)

    http://www.pbase.com/copperhill/ccd_cleaning
     
    cjcampbell, Jun 26, 2006
    #2
    1. Advertisements

  3. I've spent huge amounts of time spotting and retoucing dust spots,
    hairs, scratches, and gunk from the water (the last usually embedded
    in the emulsion during processing); it's a far bigger problem than
    dust has ever been for me with a DSLR.
     
    David Dyer-Bennet, Jun 26, 2006
    #3
  4. Matt Clara

    Scott W Guest

    It is really a filter that you are cleaning not the surface of the
    sensor so it is not as scary at it might first seem, still some care is
    needed.

    If the bulb blowing thing does not work then I try a brush. If that
    does not work I use a very small amount of alcohol on a cotton swab,
    most people would not recommend this but it works for me.

    As long as I don't shoot with f/number larger then about f/16 I have
    very little problems with dust and only rarely have to clean the
    sensor.

    If you are seeing a blurry patch it sounds like a lot more then just a
    little dust on the senser, it sounds like a bit blotch of something,
    should not be hard to see.

    Scott
     
    Scott W, Jun 26, 2006
    #4
  5. Matt Clara

    Greg \_\ Guest

    Get the sensor cleaned once a year from Nikon. Buy a backup camera.
    Never take the lens off.
     
    Greg \_\, Jun 26, 2006
    #5
  6. Matt Clara

    C J Southern Guest

    I had just this issue the other day - so I went a bought a $30 artists
    brush, and promptly smeared all kinds of crap over the sensor - guess I
    shouldn't have skipped the bit about cleaning and testing the brush first
    (but it felt so clean on my fingers!)

    Time for plan B ...

    Got an $80 "kit" from a national supplier - it consists of a small bottle of
    distilled water with some kind of 'secret sauce' added, and 12 sterilised
    long-stem medical cotton buds.

    You put 2 drops on the 1st bud and give the sensor a good clean - this
    leaves all kind of smeared water droplets which you then remove with buds 2
    & 3 (and 4 if you need it).

    In the end I concluded a number of things ...

    1. This stuff is a real rip-off

    2. 1/2 way through the process it looks aweful

    3. It worked absolutely 100% - not a single spec to be found anywhere.

    Morale of the story ...

    1. Buy one of these rip-off kits, but see if you can source the
    sterilised cotton buds from your doctor next time you visit.

    2. You're really only cleaning the glass filter over the sensor - it'll
    probably scare the crap out of you the first time, but much easier from then
    on in.
     
    C J Southern, Jun 26, 2006
    #6
  7. The dry method:

    Compressed air. For more stubborn specks use an eye shadow brush followed
    by compressed air.


    The wet method:

    A Pec pad wrapped around any swabbing device, even a chopstick, with a drop
    of Eclipse (methanol) does wonders.

    Why do people like to overcomplicate this simple process so much? Why do
    people like to waste money on rip-off kits?







    Rita
     
    Rita Ä Berkowitz, Jun 26, 2006
    #7
  8. Matt Clara

    blackeyesue Guest

    Sounds like you're talking about a black and white darkroom and/or
    scanning without d-ice. If you're going the pro lab route there are no
    dust problems with film that can't be solved by simply requesting a
    reprint sans dust spots.

    And such a helpful response you've given.
     
    blackeyesue, Jun 26, 2006
    #8
  9. There should NOT be crud on film at a good lab. The common method though is
    handle film like crap and let the scanner/software fix it. I have flawless
    B&W images. I have spent well over 25 years in pro labs and the answer is
    handle all film like it's our own. That concept has been tossed away with
    false economy. Labs will now try to squeeze the last penny out of the
    wash/stabilizer using it weeks after it should have been changed.
     
    Darrell Larose, Jun 26, 2006
    #9
  10. ICE doesn't work with silver-image B&W films, so those have to be
    fixed by hand.

    You've had much better luck with pro labs than I have, sounds like.
    People need to keep a sense of proportion. I've spent minuts of my
    life retouching out dust from digital photos; it's just not much of a
    problem.
     
    David Dyer-Bennet, Jun 26, 2006
    #10
  11. Matt Clara

    Matt Clara Guest

    I've heard of things costing an arm and a leg, but your nuts!?! Ouch! That
    goes to far, me thinks.
    ;-)
     
    Matt Clara, Jun 26, 2006
    #11
  12. Matt Clara

    Pat Guest

    I've never had a chunk of stuff on my sensor, but doesn't seem like it
    would be too blurry. Seems like it would have fairly well defined
    edges and be pretty opaque in the middle.

    Check your lens, esp. the back piece of glass. There might be
    something there.

    Good luck.
     
    Pat, Jun 26, 2006
    #12
  13. Matt Clara

    ian Guest

    my luck is just as bad. the price of pro lab is higher but quality of
    results is just as hit and miss.
     
    ian, Jun 27, 2006
    #13
  14. Matt Clara

    cjcampbell Guest

    Not so. Specks on the sensor are definitely blurry. :)

    Usually the specks are invisible -- the get lost in the background
    clutter. But against sky or large areas of a single color the specks
    become visible as little blurry dots (sometimes not so little).

    The way to check for dust on the sensor is to take a picture of a white
    sheet of paper. It does not have to be in focus; in fact, it works
    better if the paper is not in focus. You can change lenses and shoot
    again, if you want. The specks of dust will be in both pictures at the
    same location, visible as grayish blurry dots.

    The Copper Hill method is to wipe them off with a stick wrapped in a
    PecPad with one or two drops of Eclipse on it. You can buy special
    sticks that match the size of your sensor, but that is not completely
    necessary.

    Using compressed air to clean the sensor may not be a good idea. You
    can drip liquid propellant onto the sensor, damaging it permanently, or
    you might just blow more dust onto the sensor.
     
    cjcampbell, Jun 27, 2006
    #14
  15. Matt Clara

    cjcampbell Guest

    I would not recommend this method. You can drip liquid propellant from
    the compressed air can onto the sensor, permanently damaging it. Also,
    the eye shadow brush is likely to have glue on it that will get onto
    the sensor, plus pushing the dirt around on a dry sensor is likely to
    scratch it.

    The wet method is called the Copper Hill method and it works fine.
     
    cjcampbell, Jun 27, 2006
    #15
  16. Matt Clara

    Matt Clara Guest

    When you're paying pro prices, it's up to you to say if their results are
    not acceptable. In my experience, they'll reprint every time, until you
    quit bitching. You're not afraid to stand up for what's right, are you?
    ;-)
     
    Matt Clara, Jun 27, 2006
    #16
  17. Matt Clara

    DoN. Nichols Guest

    Indeed so.
    You left out one thing which is certain to make the specks
    visible if they are present -- or to hide them depending.

    That is to shoot at the smallest aperture you can. Beyond a
    certain point (e.g. more open than f11) they are very hard to find, and
    often not visible. The reason for this is:

    1) The dust is not directly on the sensor, but rather on a filter
    mounted above the sensor. (IR blocking, and anti-aliasing as
    well on some cameras.)

    2) The smaller the aperture (numerically larger), the narrower the
    cone that the light beam forms.

    3) At large apertures, the cone is larger than the dust speck, and
    thus most of the light will still reach the sensor at a given
    point, even if a dust speck is directly over it.

    4) At small apertures, the only light to normally reach the sensor
    is blocked by the dust particle, plus a blurry gray zone around
    it from light reaching it only from part of the lens.
    It is a good product. I believe that Eclipse is a particularly
    pure form of some alcohol, though I forget which. If you can get that
    directly in larger quantities, and the Pec Pads from some other source
    after your first batch, all you really need from the kit is the special
    stick, designed to maximize the cleaning accomplished by a single swipe,
    unlike cotton "buds" (called "Q-tips" (a brand name) in the US).

    If you know the shape desired, and have machining capabilities,
    you should be able to make your own stick -- but the easiest way to know
    this is to buy the kit, so there you are. :)
    Truly compressed air has no propellant other than more air, but
    it is likely to have water condensed from the air as a side effect of
    the compression.

    My choice for blowing off would be dry nitrogen, but a 3000 PSI
    tank of that is not a comfortable thing to have around the house. :)

    Some "air" blowers really are liquid CO2, and if you hold the
    dispenser in the wrong orientation, you will get spurts of liquid CO2,
    which will be cold enough so you risk damage to the protective filters
    over the sensor. The sensor itself is protected behind these.

    Enjoy,
    DoN.
     
    DoN. Nichols, Jun 27, 2006
    #17
  18. Scratches are the problem I have with pro labs, and reprinting doesn't
    help.
     
    David Dyer-Bennet, Jun 27, 2006
    #18
  19. At a small aperture, like f22.

    The sky works fine, too.
     
    David Dyer-Bennet, Jun 27, 2006
    #19
  20. Indeed, that is how I found that my camera has a dust problem. I was taking
    photos with significant sky using f/16 and it was clearly apparent that there
    was a problem once I got back to my computer to take a look.
     
    Thomas T. Veldhouse, Jun 27, 2006
    #20
    1. Advertisements

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.