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Thread: Does this mean Dust on sensor?

  1. #1
    jstp's Avatar
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    Does this mean Dust on sensor?

    Hi all,
    Hopefully this is in the right spot. I was wondering if I could get some advice. On the attached photo I have circled, very proffessionally, marks that are showing up on my photos. On this one I could not see the marks on the original colour, only when I made it B&W. I do notice them on my colour shots but mainly when shooting in the high f-stops. I can not notice anything on the sensor or on the lenses and it seems a bit weird that they are nice and round. If it does seem to be dust does anyone do their own sensor cleaning? I do not know of anywhere here in Canberra that does that. Any advice and help would be greatly appreciated.

    Cheers

    J

    Does this mean Dust on sensor?

  2. #2
    Moderator Dave Humphries's Avatar
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    Re: Does this mean Dust on sensor?

    Hi jason,

    I'd say your diagnosis is correct given the conditions under which they appear.

    I wonder, does the D3100 have the same 'dust removal' system the D5000 has?

    If so, look through menus and if you're not using it regularly (I have mine set to shake the sensor everytime I switch off and on) enable it, hold the camera base down, with a lens attached and switch off and on a few times - it may shift them if you're lucky.

    I've so far never had to clean my sensor in 45k+ shots since May 2009, any odd dust bunnies I have noticed, have been removed by the system. I am fairly cautious changing lenses and do it quickly, keep all lenses rear capped until last moment and with body opening pointing downwards while 'open'. Bet you I find one today/tomorrow now, for being so smug!

    I'm sure almost any photographic dealer will do it and in a city that big, there must be one, surely.

    There are threads here at CiC, have a search for words like "arctic" as well as "bunnies" or "dust".

    Good luck,

  3. #3
    Glenn NK's Avatar
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    Re: Does this mean Dust on sensor?

    Classic looking dust spots.

    The D3100 has a self-cleaning sensor. In the latest cameras (past two or so years) it actually works.

    Try this a few times before manual cleaning. For help on this, try googling. I've cleaned one of my sensors (six year old body) several times.

    Glenn

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    PhotoRob's Avatar
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    Re: Does this mean Dust on sensor?

    Funny, had big dust issues a few days ago and I ended up using a turkey baster to blow it out ( I know they say it can just spread dust around, however my cam's a mirrorless Nex-5n so it's real shallow) - worked great.

  5. #5
    Glenn NK's Avatar
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    Re: Does this mean Dust on sensor?

    Quote Originally Posted by PhotoRob View Post
    Funny, had big dust issues a few days ago and I ended up using a turkey baster to blow it out ( I know they say it can just spread dust around, however my cam's a mirrorless Nex-5n so it's real shallow) - worked great.
    Robert, Jason et al:

    I've been through more discussions and tests of dust removal than I pretty well care to remember. The "blower" is one of the tools that has consistently been praised for its effectiveness. And at first I was one of the detractors' of the blower, probably because I bought one and found it to be useless. I now believe that they can be useful.

    Having said all that, I'm going to ramble a bit, so ignore the following if you wish:

    Five years ago with my new 30D, I was fanatical about dust spots (they can be a big problem in many cases). I frequently stopped the lens down to f/22, focused the lens as close as possible, and shot the clear blue sky looking for dust spots. I found them of course because they are inevitable. So I purchased the blower - it didn't work. Then I purchased a wet cleaning method (bottle of cleaner and some swabs). I cleaned and cleaned, and removed all the spots. But they kept reappearing, so I kept at it until I actually became quite good at it.

    Eventually (about two years or so) after all the cleanings, I noticed that the dust bunnies didn't seem to show up. This puzzled me except that someone mentioned the possibility that lubricant on the mirror mechanism could spray off and onto the sensor surface. This seems logical, and seems to explain why in time I had no more problems; I haven't cleaned the 30D sensor for three years. However this may also be due to the fact that most of my photography in those days was flower closeups shot at f/3.5 to f/5 or so. Dust rarely shows up until apertures of f/11 or smaller.

    In those days (2006 to 2008 or so), the built-in sensor cleaning systems didn't work. One published test found that it didn't matter if it was turned on or off. Things have changed; my 5DII has a sensor cleaning that by all accounts actually works, and I think all brands have systems that do work - if they are actuated.

    The dust removal systems rely on a slippery anti-static sensor surface and a sensor shaking mechanism. If lubricant is the problem (as opposed to dust that floats in the air), it will stick and probably can't be shaken off. Anyone familiar with lubricating moving parts is aware of the problems with excess lubricant, and considering the extremely small amount of lubricant that is applied during manufacture, it seems likely that occasionally too much is applied. This is further borne out by reports of some that wet cleaning the sensor just smeared the "dust" spots around. Dust doesn't smear, but lubricant does (it's designed to stick where it's needed or it would be useless). Imagine trying to remove an oil spill from a glass table using a water moistened paper towel - it requires a solvent, and quite a few cleanings.

    When people think of dust, dirt particles come to mind, but the most common dust in a house consists of particles of fabric, carpets, and other such stuff - and it floats in the air (we've all seen a sunbeam coming into a dark room and illuminating thousands of dust particles). This is why I don't think pointing a camera down will prevent air currents from moving this type of dust into the camera. Now if one is shooting a rodeo where horse hoofs are stirring up clouds of dust (dirt particles), this will be an issue and should be avoided because this type of dust is abrasive (some of it consists of tiny particles of rock/stone). This also indicates why a blower is a good idea.

    As I said, the newer cameras have cleaning systems that work - I haven't yet swabbed (wet cleaned) my 5DII in a year and one half - the built-in system seems to be working. This isn't to say that some of us won't have a problem, but the solution is well documented on many websites and I'll provide a few links to articles I think are well done:

    http://www.tribcsp.com/~sigma2/SensorDust01.html

    http://www.cleaningdigitalcameras.com/index.html

    http://www.copperhillimages.com/

    http://www.bobatkins.com/photography...nsorclean.html

    Glenn

  6. #6
    jstp's Avatar
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    Re: Does this mean Dust on sensor?

    Thanks for all the answers. I will give the self clean a couple of runs and buy a blower before I go for the self clean. Thanks for the links Glenn, they were helpful.

    Cheers

    J

  7. #7
    Glenn NK's Avatar
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    Re: Does this mean Dust on sensor?

    Quote Originally Posted by jstp View Post
    Thanks for all the answers. I will give the self clean a couple of runs and buy a blower before I go for the self clean. Thanks for the links Glenn, they were helpful.

    Cheers

    J
    You are welcome, and keep in mind that this is not the "end of the world".

    G

  8. #8
    arith's Avatar
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    Re: Does this mean Dust on sensor?

    I've cleaned my current camera exactly 3 times using Dust Aid dry cleaning. I must have cleaned my old one a hundred times using various methods but in the end I used Dust Aid and practiced the wet method, and my old camera certainly had a clean sensor when I sold it to a dealer.

    If you are going to clean it then make sure the battery is on full charge, use something like Dust Aid and avoid the edges. No need to buy a loupe, just go for all the sensor once with the dry method and then test, if it isn't done you might consider the wet method but be careful to avoid the edges.

  9. #9
    shreds's Avatar
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    Re: Does this mean Dust on sensor?

    Steve,

    I beg to differ on the use of a loupe. (Or maybe my eyes are getting dim). An illuminated one at x5 or x7 like those that come with the Arctic Butterfly kits highlight stuff that I would otherwise miss, and is particularly useful when determining where on a mirror for instance, there are marks (ok they won't show on the picture but I find nevertheless annoying). A good look around at the sensor before cleaning can determine the type of object too be removed and I would recommend the Arctic Butterflys for both wet and dry cleaning kits. I probably do it twice a year, dependent upon the environments I have been in.

  10. #10
    arith's Avatar
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    Re: Does this mean Dust on sensor?

    Cheers Ian; I just dab four times inside the gold rectangle, but I suppose a loupe is useful and time saving, so far I've been lucky.

  11. #11
    darkslide's Avatar
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    Re: Does this mean Dust on sensor?

    I am so glad I came across this thread as I have exactly the same problem of 'spots' on my images and I wondered if it was dust on the sensor.

    So many thanks (from me) for the helpful replies.

    However, one thought occurred to me - why is it that these problems show up more from f11 on ?

    Is it simply that another artifact of diffraction? The fact that the light hits the 'dust' at a greater angle and thus leaves a shadow? I must admit that I rarely notice any marks when I shoot wide open...

    Ian

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