Yes, I apologize for not mentioning this before. On my lens I guess they tightened everything pretty tight. So tight, in fact, I could tell the orientation even after I took everything apart.Jon Rosswrote:Hmmm, I just tried this, and while completely easy and successful for cleaning out the dust, I couldn't help but notice that the rotational positioning of the front element is critical as its angle creates an offset for the element - try undoing the screws (take a photo of their position before you do this!) and twist the front element. It moves back and forth according to the angle. So, seeing as I didn't take the precaution of taking a photo of the screw positions before undoing them, my guess is my lens is now in need of calibration. Suck. Let this be a warning to you all! Jon

Really, then why does it go away when I use a different lens?One DaveTwrote:Big Handswrote:For those that think dust on the inner elements has no effect on photos:That's not dust on a lens. That's dust on a sensor.... quite a different matter.If you trust yourself, then you can put the camera in bulb mode, and with a lens off, gently blow some air in with a blower bulb, and most of that will probably go away.... else someone will chime in with a safer way to clean it out.To the OP, I've had my 17-55 for almost a year now, and there is not a single spec of dust that I can see in my lens. From my point of view, associating dust attraction with a 17-55 is the most unsubstantiated rumor related to canon gear I'm aware of.

Try stopping the other lens to the smallest aperture, and taking a picture of the sky. I think you will find the dust in the same spots. Dust in the lens does not show up as focused spots, but reduced contrast.

Does anyone know if recently purchased copies also have the dust problem? -- JerryGSee my galleries at: http://www.pbase.com/jerryg1

Mine was fine 5 weeks old, but always used a UV from day 1 -- Everyone is entitled to my opinion.

Big Handswrote:Really, then why does it go away when I use a different lens?Can you post the comparison shots at the same aperture?

This whole business of zoom extension bringing in dust is very odd when I think about it. Unless the body and lens are perfectly sealed air will come in every time the interior volume is increased. In most cases you don't know exactly where it's entering, but it's carrying the same dust in any case.Considering the vulnerability of sensors, mirrors, and lenses, wouldn't it make sense for camera makers to add a "filtered port" with a replaceable dust filter somewhere on the body/lens? ( I expect royalties if anyone does this. ;-)) -- JerryGSee my galleries at: http://www.pbase.com/jerryg1

funny, but that is one thing I also have thought. It should be simple, but it would require a sealed lens to force the air flow to go trough this port.-Roger

no text!

One DaveTwrote:Big Handswrote:For those that think dust on the inner elements has no effect on photos:That's not dust on a lens. That's dust on a sensor.... quite a different matter.If you trust yourself, then you can put the camera in bulb mode, and with a lens off, gently blow some air in with a blower bulb, and most of that will probably go away.... else someone will chime in with a safer way to clean it out.To the OP, I've had my 17-55 for almost a year now, and there is not a single spec of dust that I can see in my lens. From my point of view, associating dust attraction with a 17-55 is the most unsubstantiated rumor related to canon gear I'm aware of.You are very lucky I bought mine from B&H last December it has been back once in March 07 1200 shots later its a starfield again.They did a courtesy cleaning lol something is wrong with that it is like Canon said thats normal. So its going back again.I read it is easy to clean it yourself just pull the ring off, it is glued on remove 3 screws and pull the front element out when you put it back in check for possible leaks. I may try this after all it is a pain sending it back every few shots. It would be a hard lens to replace. Ron

G Tomwrote:I had a filter on mine which seemed to prevent dust getting in. I subsequently dropped my lens anf broke the filter. Since 77mm filters are kind of expensive I never got around to replacing it. Well, now there's a ton of dust in my lens.If it's still under warranty, will Canon clean it for free?After seeing that plastic ring come off there is no doubt where it is coming from. And certainly putting a filter would block the dust from entering there.Now there should have been a breathable piece of foam and a threaded piece of metal to cure the dust inlet shame on Canon I guess 1000 isn’t enough.There should be a class action about this, that is so fn unbelievable for a big company to pull stuff like this. Maybe there retirement fund is costing them too much (like GM) lol to spare a piece of foam and a thread in cap in place of the sticky plastic. Maybe its chinatized Then again everyone is cutting corners today quality is a thing of the past.Ron

Here's one at f/16 panned with sky since it's been cleaned:Here's one at f/22 taken focused on my ceiling:I'll take a still of the sky tomorrow (it's dark outside right now) at f/22..... :)Believe me, I wish I could find a way to say it was sensor dust, but it's looking kind of grim.Meanwhile, here's one from my Sigma taken at f/16:Keep 'em comin'.......photoguynorthwrote:Try stopping the other lens to the smallest aperture, and taking a picture of the sky. I think you will find the dust in the same spots. Dust in the lens does not show up as focused spots, but reduced contrast.

The EXIF data can be had there.Patrick Coxwrote:Big Handswrote:Really, then why does it go away when I use a different lens?Can you post the comparison shots at the same aperture?

Big Handswrote:Really, then why does it go away when I use a different lens?Those specs on the sensor may go away ( or move) just from taking a picture, or the vibration of moving around. They may move from turbulence cause from the mirror flapping, though you can count on them coming back since they are still trapped inside..... at least this is my experience. The best thing to do is blow it out with a blower bulb. Just fire a bulb shot with the lens off, and it's quite likely you'll see the dust in same patern as a recent photo.. inverted ofcourse.good luck, Dave

I just cleaned mine myself and must say all the dust had a big affect on color quality. Looks like it should now.If any of you attempt to do it yourself make sure you mark where the 3 screws were because underneath the element is a bunch more holes to adjust the lens. Putting it in other than the originals could rain on your parade.Hate to say it but I'm going to need a filter now. Filters screw in like that ID ring should of, this will greatly reduce the dust consumption.

Hi,wow--I never saw this effect caused by dust inside the lens. As one other poster already wrote, I only know of reduced contrast because of dust inside the lens or messed up lens elements (had that problem with my 35-350L years ago).The other point of dust leading to inner wear is for sure an issue even I've never heared of anyone having had this problem.I guess, I've learned something.Greetings, MichaelBig Handswrote: For those that think dust on the inner elements has no effect on photos:xttp: photos.imageevent.com/johansen01/pixelpeepersdelight/oddballstuff1/demonstrationstuff1/IMG_5434a.jpgMichael Engelenwrote:...just out of curiosity: why do you care about a few dust spots in the lens? Did you experience bad photgraphic results because of that? Do you also care about some dust on the dashboard of your car?Yes, I know, dust spots disturb the perfect look and finish of a (new) lens.Greetings, Michael