Dirty Lens... Tips?

[nudicles]

Hey Guys,

Wanted to see if you guys could help me out. I got a new lens, the Pentax 50-200mm zoom, and after I started taking pictures I noticed that there was what appeared to be a spec of dust that was showing up on the top right hand corner of my pictures. Here are a few examples:

at 50mm
http://picasaweb.google.com/n00b.ws/Hawaii/photo#5192011171232020498
http://picasaweb.google.com/n00b.ws/Hawaii/photo#5192011235656529954

at 200mm
http://picasaweb.google.com/n00b.ws/Hawaii/photo#5192011377390450754

I've tried cleaning the lens a number of times, to no avail. You guys have any idea what it could be, and how I could get rid of it? (My other lenses are fine, in case you're wondering).

Thanks!

[nism]

i can't see the pictures, but you may be in need of a sensor clean.

[nudicles]

Changed the pictures to links.

I thought about the sensor clean, but wouldn't I notice the "spec" with all my lenses in that case?

[rx_morph]

I suppose it's possible that a dust particle could have gotten into the lens while it was being made in the factory. Although I imagine that's extremely rare considering they check and recheck them after they are constructed to ensure quality. Just a thought though...

[TheWengler]

I think it's dust on the sensor. It should show up with both lenses. It will be more noticeable when you stop down and less noticeable when you open up the lens.