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07-27-2009, 12:47 PM   #1
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DA* lens blowing air from between the body and lens when zooming?

I've had the 16-50 DA* for a week now, and today I noticed that there's a slight wind blowing from the mount when I zoom the lens towards the wide end (lens elements move towards the body, creating air pressure). How much this weakens the weather resistance? Does this happen with your lens?

07-27-2009, 12:59 PM   #2
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Well, the lens is supposed to be weather-sealed, so I imagine that there are rubber gaskets with tight tolerances preventing ingress of dust and water. However, I imagine that some dust can still get in.

I don't have any real experience with this though (I own a 16-50mm, but haven't used it in bad weather yet).
07-27-2009, 01:11 PM   #3
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It was a rainy day when I bought the 16-50/2.8, going outside in the rain was the first thing I did. About half a week in, it was raining heavily during a shopping trip so I pulled the camera from my bag and took a few shots just because I could. And man, was it fun. I've never laughed so hard when taking shots. It seemed like the AF was becoming more difficult when there was raindrop on the front element though.
07-27-2009, 01:36 PM   #4
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I think it's normal behaviour. When I tried Olympus E-3 and the zuiko 12-60mm there was some air blowing through the holes on the backside of the camera when zooming. They are both sealed too.

muus.

07-28-2009, 05:30 AM   #5
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all weather sealed zooms and bodies have this problem because the lens mount is the hardest to seal.

THis problem is more serious as a function of the overall change in dimensions of zoom lenses while zooming.

simply put a sealed zoom lens is a pump and changing the focal lemgth changes the internal volume, the air has to get in somewhere. You have found that this is the lens mount.

to this end, I think the weather sealed lens concept is a bad idea. it would be better to allow the lens to breathe in order to equalize not only pressure but humidity.

I can understand sealing the body, and sealing aspects of the lens but the weather sealed concept just beggs to concentrate the pressure differential on the weakest part, the mount. as a result, all of the dust will get in at the mount, and be in the area of the sensor and mirror.
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