Dust in a new 24-70 f2.8. II lens!? Not happy with the Canon's response!

Discussion in 'Canon EOS' started by proy, Jun 4, 2013.

  1. Hi.
    Last September, I purchased a new MarkIII along with the expense 24-70 f2.8 II lens. As you know, this is a $2,500 lens!
    I went abroad (asia) for 3 months with it, only to find a few problems:
    1. My rubber grip around the zoom started to unglue itself.
    2. I came to find a dust spot inside of it, in the middle.
    3. Might be just me hallucinating but, turning the zoom in and out almost feels a little hard, like grindy kinda.. some kind of friction. I might just be trying to find problems with it here but...
    Of course, the lens being under warranty, I sent it in for inspection and repairs.
    Now the rubber grip doesn't worry me. They'll replace it, it should be fine. However, the dust part does annoy me! I bought a 5DMarkIII along with that lens for one specific reason: they are both pro gear, weather sealed! And already, I'd have a dust showing up. Before I'm asked, I'm the kind that takes super good care and is very cautious when changing lenses, etc. I take great care of my gear! On top, of course I always have pro-rated filters on all my lenses, all the time! B+W Filters...
    Now, on top of the fact that the rubber grip is "back ordered" and I'll have to wait like 3 more weeks (on top of the 3 I've already been waiting), they came and said "oh those spots are normal. it can happen sometimes when zooming in or out. If it doesn't affect the image quality, we will not do anything". Normal!? WTH!? If I wanted a lens for which it's "normal" to accumulate dust, I would of sticked with my Rebel and my 15-85... I mean come on Canon!
    It's not like there are that apparent; you do have to look for it, but it worries me for the future! Am I getting what I paid for?
    My hole kit is still under warranty until September. I would love to hear your input and advice as if I should even care about this or not...
    Much thanks in advance.
    Patrick
     
  2. Don't worry about a few minor dust spots: it will make no difference whatsoever. I assume Canon think the same. You have had the lens for 7 months, they don't feel they have a responsibility to keep it free of dust. It is weathersealed, not dust sealed (this is not possible). If you want to have the dust removed they will have to disassemble the whole lens and this will cost you. They won't do it for free. If it was really dusty then they probably would, but if you have to "look for it" then clearly they won't do it under warranty. I don't blame them. Chill and relax about the dust. Can't comment about the zoom feel. I guess Canon think it's normal.
     
  3. zml

    zml

    Yeah, dust is normal. Dust is everywhere and that includes inside of every lens I have ever seen or used. No problem unless the particles are really large, say over 1 mm, or have accumulated in single are of the lens en masse.
    No filter will stop dust and since dust particles are/can be smaller than water droplets, even weather-sealed optics will eventually accumulate some dust inside.
     
  4. "Don't worry about a few minor dust spots: it will make no difference whatsoever. I assume Canon think the same."
    If you are still under warranty send it back to Canon ASAP, 2500 dollars is nothing to sneeze at....
     
  5. There is no lens that I've ever encountered that is without at least one "dust" spot inside of it. Don't worry about this - it makes no difference.
     
  6. I guess I just don't understand what the big deal is about the dust. I can see the rubber grip ticking you off, I mean WTH!?, a nearly new, $2500, pro quality, top shelf, lens is already falling apart!? that is just redonculous! On top of that, you have to wait 3 extra weeks for them to fix it !? talk about adding insult to injury! wow!, I mean, just, wow!
    Seriously though, ...yes... 'normal' is absolutely right. The dust is everywhere, and on a long trip with lots of zooming, pressure differentials, and concentration gradients, the air gets mixed up, period. Air goes in, and air goes out. It's called physics. Bottom line, nobody has ever built a sealed zoom lens for SLR use. If it really, really, bothers you (because it doesn't really matter... at all!), get an underwater enclosure for your camera and the lens, because, while that won't probably actually fix anything, it'll probably make you feel better, which, as we all know is far more important.
     
  7. How good are the images? You didn't mention that...
     
  8. I sympathise Patrick, but I agree with everyone else.
    For lenses to be guaranteed dust-free they'd need to be assembled in a cleanroom, and the price of the lens would likely be a lot more than $2500.
     
  9. To expand on what others are saying...
    I think you misunderstand what it means for a lens to be weather-sealed. It means that air/moisture/dust/dirt don't enter the lens directly from the outside (although common sense tells us a thin film of moisture can slide through a seal). What it DOES NOT mean is that outside air can't get into the lens at all.
    The seals only block the DIRECT routes of entry. The speck of dust inside your lens (geesh, it's only one speck?), if not present from manufacturing, would have gotten there through one of the non-sealed orifices of your 5D (?) Mark III (perhaps a battery or card door?), through the innards of the camera, through the mirror box, and in through the backside of the lens.
    You might question why the camera and lens aren't sealed entirely. It all depends on lens design, but if a camera is going to have any sealed lens with telescoping barrels (like your 24-70 II), the volume of your camera/lens will change as you zoom or focus. This would create an enormous pressure or vacuum that you would find physically difficult to overcome. It would also create condensation problems. So there is a need to let air enter and leave the camera body and/or lens somehow.
    Some lenses don't have this issue. They are internally focusing and zooming. These include lenses such as in the 70-200 family. Other lenses like the 17-40 become internally focusing and zooming if they wear a filter on the front. These lenses do not draw air through the camera body when focused and zoomed, because they do not change volume. (This makes the telephotos less compact.)
    If I could engineer these camera systems, I would do something about this source of dust entry into cameras. (Dust in the lens isn't an issue, BTW. Dust on the sensor is the real issue.) I would use one of two approaches:
    1. Completely seal the camera body, and require that all lenses vent directly with outside air. Or...
    2. Completely seal the camera body, with the exception of a vent hole in the bottom of the camera with a user-replaceable paper filter. This would be similar to the way hard disc drives vent.
    Anyway, don't worry about your dust speck. Let Canon replace the ring, and be happy. You've got an awesome rig.
     
  10. Lots of my lenses have various dust spots or imperfections. Eos, FD, hassy, schneider and nikon lf. I haven't looked at some, of no interest since I'm happy with my images.
    Haven't used a skylight filter on any lens since 1990. I risk it and go naked. So far no harm done and I am not gentle with my equipment. Because it IS equipment.
     
  11. I would absolutely love my 24-105mm to have one dust spot inside it. At the moment it looks like a child's sandpit in there but the images are still as great as ever. Chill out dude, you're worrying about nothing.
     
  12. Most of my new lenses ship with factory installed dust! Like others have written, dust happens as lenses can't be airtight since elements must move and displace air in the process. And fast and frequent zooming enhances the venting and sucking in of air. And air has dust...
     
  13. if you don't want to see dust in your lenses stop looking inside of them. dust is everywhere. chill.
     

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