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Thread: Dust found in lens, Normal or Abnormal?

  1. #21

    Default Re: Dust found in lens, Normal or Abnormal?

    Quote Originally Posted by jsprtan View Post
    Usually the better lens are. If it is weathered seal it should be air tight like the L lens. As for fogging it is harder as there are too many factor that can affect that.
    LOL you really think L lenses are airtight? Please read up a bit more.
    Alpha

  2. #22

    Default Re: Dust found in lens, Normal or Abnormal?

    Quote Originally Posted by jsprtan View Post
    L Lens should be. Cause I have seen someone on Line leaving the whole Canon 7D and L-Lens under his shower for testing. If water can go in air too will.
    Splash-proofing a lens is VERY different from "air-tight". BTW, the physical properties of water and air are very different too.
    Alpha

  3. #23
    Member jsprtan's Avatar
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    Default Re: Dust found in lens, Normal or Abnormal?

    Quote Originally Posted by Rashkae View Post
    Splash-proofing a lens is VERY different from "air-tight". BTW, the physical properties of water and air are very different too.
    Ha ha ha ha.... Every day we learn something new.... thks.

  4. #24

    Default Re: Dust found in lens, Normal or Abnormal?

    Quote Originally Posted by jsprtan View Post
    Ha ha ha ha.... Every day we learn something new.... thks.
    Most of us learn this in primary school...
    Alpha

  5. #25

    Default Re: Dust found in lens, Normal or Abnormal?

    I think longer zoom lens likely to attract more dusts.
    It is normal. Even my PNS camera got dust.

  6. #26

    Default Re: Dust found in lens, Normal or Abnormal?

    dust if everywhere, theres no escaping it. anw a spec of dust if not gonna affect image quality. even shattering the front element of ur lens is not gonna significantly degrade ur image quality (still usable). go search google, there are some blogs where unlucky ppl shatter their lens and yet still can use them cos the electrical systems are fine. at wide apeture the lines and shards of glass dissappear (same effect as shooting thru a wire fence)
    Canon 550D Sigma 17-70mm f2.8-4 HSM OS | 50mm f1.8 II | 55-250mm f4-5.6 IS | Di622 | BP-550D

  7. #27
    Member Aaronlim81's Avatar
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    Default Re: Dust found in lens, Normal or Abnormal?

    Quote Originally Posted by jsprtan View Post
    L Lens should be. Cause I have seen someone on Line leaving the whole Canon 7D and L-Lens under his shower for testing. If water can go in air too will.
    Disappointed.
    EOS 7D-Canon 100-400 F4.5-5.6L IS/ Sigma 18-200mm F3.5 OS/ EF50mm f1.8/ Speedlite 580EX2

  8. #28
    Member jsprtan's Avatar
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    Default Re: Dust found in lens, Normal or Abnormal?

    Quote Originally Posted by Rashkae View Post
    Most of us learn this in primary school...
    Wah, which Primary school are u in??? I didn't know they teach about zoom Lens.

  9. #29

    Default Re: Dust found in lens, Normal or Abnormal?

    Quote Originally Posted by Aaronlim81 View Post
    I don't understand why don't the lens manufacturer design the lens in such a way that it's air tight and doesn't cause fogging. cool right? Maintenance free.
    If air tight, than the zoom lens won't be able to zoom in/out. Lens will always such

  10. #30

    Default Re: Dust found in lens, Normal or Abnormal?

    Quote Originally Posted by jsprtan View Post
    Wah, which Primary school are u in??? I didn't know they teach about zoom Lens.
    They teach about the different properties of water and air, and the surface tensile strength of water.
    Alpha

  11. #31
    Member jsprtan's Avatar
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    Default Re: Dust found in lens, Normal or Abnormal?

    Quote Originally Posted by Rashkae View Post
    They teach about the different properties of water and air, and the surface tensile strength of water.
    Hahaha, what u have referred is suface tension not tensile stregth.

    Ha ha, so u really think they are so different?

    For a air and water they are different but very close, as long as air can flow in water will too. The different is so small and only if u look at it from the micron level than u will be able to seperate water and air. Only way control this at constant pressure and testing parameters is to use a membrane where the pores of the membrane is so so so small in the scale of micro level that it only allow air in and not water. This material is so expansive and heavily patent that I am sure no camera company will use it in their lens.

    So u think the camera maker is a membrane manufacturer?

  12. #32

    Default Re: Dust found in lens, Normal or Abnormal?

    Quote Originally Posted by Rashkae View Post
    They teach about the different properties of water and air, and the surface tensile strength of water.
    Quote Originally Posted by jsprtan View Post
    Hahaha, what u have referred is suface tension not tensile stregth.

    Ha ha, so u really think they are so different?

    For a air and water they are different but very close, as long as air can flow in water will too. The different is so small and only if u look at it from the micron level than u will be able to seperate water and air. Only way control this at constant pressure and testing parameters is to use a membrane where the pores of the membrane is so so so small in the scale of micro level that it only allow air in and not water. This material is so expansive and heavily patent that I am sure no camera company will use it in their lens.

    So u think the camera maker is a membrane manufacturer?
    weather seal i think is a 'more' protection to a state of atmosphere (wind, temperature, moisture, pressure) and not a subjection to any single element in a extreme case.

    Certainly weather seal is not a 'water tight', 'air tight' proof.

    However i think it is more water proof than air proof if we just paid a little attention to the nature of weather.

    1) Rain or droplet fall from high to low position due gravity.
    2) Air does not 'obey' gravity and can flow into any tiny hole when there is wind or changes direction due to a change of temperature (hot air rise and cold air take up the 'empty' space.

    A simple test:
    Tho air and water show a similar properties in surface tension

    1) Pocket of bubbles (in a cup of water) rushes upward only no matter how hard you shake in diff. direction
    2) How hard you throw a cup of water it will still fall to the ground.

    Thu more Lens more 'water proof' is a combination of factors (nature and human) and water tension but 'air proof' will have much less advantage.

  13. #33

    Default Re: Dust found in lens, Normal or Abnormal?

    if L lens is water proof ...
    i think i bathe with my lens everyday haha ...
    den i can bring my camera + lens go snorkling WITHOUT buying EXPENSIVE underwater casing haha ... can save alot money + take WONDERFUL photo

  14. #34

    Default Re: Dust found in lens, Normal or Abnormal?

    Quote Originally Posted by o0darkn3ss0o View Post
    if L lens is water proof ...
    i think i bathe with my lens everyday haha ...
    den i can bring my camera + lens go snorkling WITHOUT buying EXPENSIVE underwater casing haha ... can save alot money + take WONDERFUL photo
    Then should be Water Resistant not water proof like

    Water Resistant does not mean you can go diving also... they are classified by their degree of water resistance to indicate how well can it is sealed against ingress of water + pressure.

    L Lens (same type of Lens) will have diff price with diff. degree of water resistance.

    30m +200
    60m +350
    150m +600
    200m +850

  15. #35
    Moderator daredevil123's Avatar
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    Default Re: Dust found in lens, Normal or Abnormal?

    Quote Originally Posted by Aaronlim81 View Post
    I don't understand why don't the lens manufacturer design the lens in such a way that it's air tight and doesn't cause fogging. cool right? Maintenance free.
    Cool. The lens will be fixed focal length (ie no zoom), and there is no manual focus and only has AFS. And you have to pay more than 3k for it. And it cannot be serviced, if any of the parts failed inside the lens.

    Very cool indeed.

  16. #36
    Moderator daredevil123's Avatar
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    Default Re: Dust found in lens, Normal or Abnormal?

    Quote Originally Posted by jsprtan View Post
    Usually the better lens are. If it is weathered seal it should be air tight like the L lens. As for fogging it is harder as there are too many factor that can affect that.
    Quote Originally Posted by jsprtan View Post
    L Lens should be. Cause I have seen someone on Line leaving the whole Canon 7D and L-Lens under his shower for testing. If water can go in air too will.
    The real test for air-tightness, is to submerge the entire Lens into a bucket of water. If water does not get into the lens, then you can say the lens is airtight.

    Maybe we can do a demonstration with your L lens?


  17. #37
    Moderator daredevil123's Avatar
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    Default Re: Dust found in lens, Normal or Abnormal?

    Quote Originally Posted by paesyl View Post
    Then should be Water Resistant not water proof like

    Water Resistant does not mean you can go diving also... they are classified by their degree of water resistance to indicate how well can it is sealed against ingress of water + pressure.

    L Lens (same type of Lens) will have diff price with diff. degree of water resistance.

    30m +200
    60m +350
    150m +600
    200m +850
    It is not even water resistant. It is weather-resistant. Meaning it can take some splashes, or rain drops, but if you submerge it, it is farewell.

  18. #38

    Default Re: Dust found in lens, Normal or Abnormal?

    Quote Originally Posted by jsprtan View Post
    This material is so expansive and heavily patent that I am sure no camera company will use it in their lens.

    So u think the camera maker is a membrane manufacturer?
    Thank you for proving my point. You're the one who goes on and on about the L lenses being airtight, yet you just contradicted yourself.

    I suggest you read up on what "weather-resistant" means. Simple water splashes are fine so long as there is no additional barometric pressure on the seals.
    Alpha

  19. #39

    Default Re: Dust found in lens, Normal or Abnormal?

    my new 50 1.8 has more dust than my zoom lenses. no idea why.
    Canon.550D|EF-S 18-55mm| EF-S 55-250mm| EF-S 18-55mm 1:3.5-5.6| EF 50mm 1:1.8|Di866

  20. #40
    Moderator Octarine's Avatar
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    Default Re: Dust found in lens, Normal or Abnormal?

    Quote Originally Posted by furyhawk View Post
    my new 50 1.8 has more dust than my zoom lenses. no idea why.
    The design is quite simple and a bit dated. Just look how much space there is between lens barrel and front element (which is rotating and extending during focusing).
    EOS

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