[LeoTaylor]

Fins won't make a difference. A blower is a blower. ...

Differences I've observed in various blowers:

The Giotto fins do not affect cleaning, but they do make the blower stand up on a desk.

Some of the better blowers "inhale" from the rear (including Giotto). This keeps them from drawing in the dust you just blew it out of the camera.

Blowers vary as to how strong a blast of air they provide. You want strong but not earth shattering.

Some shapes are hard to squeeze without the nozzle bending to one side and hitting the camera.
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My original blower rolled off the desk often, was not big enough to blow well, inhaled from the nozzle, and was a awkward shape. I bought Giottos for my wife and me based on advice from this forum. We are happy with our Rockets.

[Clicker]

You sure it's not some type of liquid stain (water mark) on the front/rear element or the inside mirror?

[Petermgr]

. . . . I cleaned the front lens and used a lens cleaning cloth on the back lens . I also did the K200D auto mapping of defective pixels but nothing helped. Very annoying in the shots it appears now that I see it . . . Any suggestions other than send the camera and/or lens to Pentax. Looks like I got a defective camera or lens. Thanks for any suggestions.

When I first received my *istDS over 3 years ago I had spots show up on my images. It was dust on the sensor and I went through so many techniques of cleaning the sensor, including a local camera shop. In the end I settled on using Sensor Brush products. I have a soft thin brush for dry removing spots when I'm away from home. I have a heavier brush for more stubborn spots, and finally I have the cleaning swabs and liquid for really stubborn spots.

I do a lot of hiking in dusty locations and change my lens often. I check for spots by stopping down my lens and shotting the sky. I use my soft thin brush for dry cleaning the sensor 90% of the time and have very good success.

Again, I've tried just about everything including the blower, but nothing will replace the cleaning tools I have now. I've never scratched my sensor and have not blown in dust behind the first sensor layer. I can tell you that after 3 years and 30,000 images, of doing multiple cleanings, it's easier than you think. You just need to be gentle.

Despite the dust removal features in the camera, you will on occasion get a piece of dust on your sensor that requires physical cleaning. And if you're careful you can manage to do your own cleaning.

Peter

[Marc Sabatella]

You sure it's not some type of liquid stain (water mark) on the front/rear element or the inside mirror?

There is no way a mark on the mirror could ever show up in a picture the mirror flips out of the way. And while something on the lens can indeed affect the picture, it would generally produce a much larger fuzzier effect. No, what is shown here is classic sensor dust.

[alohadave]

The other thing to remember is to make sure the camera is switched off when changing lenses.

That has no effect on how must dust settles on the sensor. I change my lens 3-4 times per shoot and I usually leave the camera on.