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Old May 9, 2006, 4:42 PM   #1
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don't ask me how but i noticed some spots on my iages and took a look at the lens (efs 17-85) and noticed dust inside the lens. how is this possible? ar the lenses not sealed completly? and what can i do about it? is there a way to open the front to remove the dust or does the lens need some vacation over at canon ?
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Old May 9, 2006, 9:01 PM   #2
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The spots on the images are most likely from the dust on the sensor itself.
Dust on the lens do not show on the images since they are not on the focusing plane! :idea:
-> The most dust on the lens can do is to reduce contrast that's all... :?
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Old May 10, 2006, 2:04 AM   #3
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NHL is 100% right.

For a fun experiment take a coin-sized piece of paper and hold it in front of part of your lens then take a few test shots.

You can't see it right? But the picture quality is down overall. If you can't see that what chance of seeing a bit of dust?

You have dust on your sensor. Check out the zillions of threads on how to clean it.
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Old May 10, 2006, 2:22 AM   #4
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i haven't checked yet as i'm off to work but its a bit weird, if its dust on the sensor which i somehow doubt cause i can actualy see it on the lens. how does it get there, i currently just have this one lens, put it on once never took it off. is it possible that dust can enter the body even if a lens is mounted?
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Old May 10, 2006, 5:48 AM   #5
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dkmac wrote:
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... how does it get there, i currently just have this one lens, put it on once never took it off. is it possible that dust can enter the body even if a lens is mounted?
You're exactly right there! :idea:

When you zoom in or out the lens extends and retracts correct?
What happens when your chest (or lung) expands - air comes in... and comes out when you breathe out

To minimize this, look for lenses that are designed to have internal zooming, i.e. thoses lenses barrel do not extend or retract (and does not shift weight too on the longer tele). Some of the more expensive L lens have dust + water seal as well, but they are mainly for environmental protection like shooting in the rain or desert - Dust on the lens are 'invisible' on the film plane! :O
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Old May 10, 2006, 10:28 AM   #6
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as where talking about enviromental effects on the camera, how secure is it to shoot images when it rains or snows on my current setup (30D+EFS 17-85 and a EFS 60M on its way)
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Old May 10, 2006, 10:40 AM   #7
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dkmac wrote:
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... how secure is it to shoot images when it rains or snows on my current setup
I would not tried it - moisture is OK, but if you're drenching it you might need a different camera/lenses designed for it (1D/1Ds.. etc)

BTW check this out from a 10D : http://www.pbase.com/nhl/image/53557673
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Old May 10, 2006, 1:29 PM   #8
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is this an image you took? did the camera survive? ;D .. from the image it looks like pretty heavy rain
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Old May 10, 2006, 2:55 PM   #9
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dkmac wrote:
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is this an image you took? did the camera survive? ;D .. from the image it looks like pretty heavy rain
You bet it did!

They called it "liquid sunshine" down there
... and I'm going back next month!

FYI - http://www.kirkphoto.com/aquatech.html
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