amazing dust inside lens!!!!

[doubldogz]

While stitching some photos together, the same series of dots and short lines were visible from frame to frame. It seemed unlikely (but possible) that I was negligent in cleaning my lenses.
Checking the lenses revealed the source of my problem-the Canon ES 70-300 IS 1:4-5.6 lens that I used had dust on an internal surface of a lens element! How the hell did that happen! How do you get dust on the inside of the lens?

Does it have to be serviced by Canon or can it be cleaned at home? Any help will be greatly appreciated.

[agesilaus]

Are you sure that you don't have a dirty sensor? That's a lot more likely source of spots. It is possible to get dust inside your lens, but I don't that that will result in spots since the lens surfaces are not brought into focus.

L series lenses are weather sealed to prevent that.

[doubldogz]

The dust is clearly visible if you look through the lens after it's been removed from the camera. Wiping it with a cloth does nothing-it's clearly inside the lens.

[doubldogz]

The dust is clearly visible if you look through the lens after it's been removed from the camera. Wiping it with a cloth does nothing-it's clearly inside the lens.

[NikNikon]

You may have dust inside the lens but as agesilias said the cause of specs in your photos is dust on your cameras sensor. So you have two problems, the latter is the one that's going to effect your picture taking. Check out this link, everyone who owns a DSLR has to deal with this sometime.

http://www.copperhillimages.com/index.php?pr=tutorials

[FredG]

Not questioning whether or not you're seeing dust inside the lens. I've read reports over the years of dust inside a lens, especially the 100-400 pump action. Pretty easy to verify which is the the source of the spots, though. Shoot a blank wall in Av at f/22 with the 70-300, then again with a different lens. If both frames have spots in the same place, it is clearly from the sensor. If spots only appear on the70-300 frame, it is clearly from the lens. If they both have spots, clean the sensor and repeat the test.

[swartzphotography]

although this will deffinately work to figure out if the lens is causing a problem the usual suspect of spots on pictures is sensor dust. typicly dust on the lens will result in focusing problems and general poor picture quality all around. but wont result usually in spots on the pics as the lens can not usually focus on an object thats that close to it so it usually throws it so out of focus its indestiguishable as anything and thats when you usually get just a generally poor photoNot questioning whether or not you're seeing dust inside the lens. I've read reports over the years of dust inside a lens, especially the 100-400 pump action. Pretty easy to verify which is the the source of the spots, though. Shoot a blank wall in Av at f/22 with the 70-300, then again with a different lens. If both frames have spots in the same place, it is clearly from the sensor. If spots only appear on the70-300 frame, it is clearly from the lens. If they both have spots, clean the sensor and repeat the test.

[Anders Östberg]

If I look closely I have varying amounts of dust inside most of my lenses. As already said, this does not affect the image in any way, if you see spots in your photos you have dust on your sensor.

[FredG]

I stand corrected. Mark and Anders are both right. What I suggested will only reveal a dirty sensor.

[doubldogz]

Sorry guys-there's no dust on the sensor. Switching lenses eliminates the dust. The dust is clearly visible on the inside of the glass element on the back end of the zoom lens (unless there's an optical illusion that I'm not aware of). Any suggestions?

[Anders Östberg]

It must be a sizeable dust particle to show up in a photo, though I guess it's more likely if it's on the rear element.

Only suggestion in that case is to have the lens cleaned at a service center... don't know what that would cost. Maybe it would be possible to shake and/or bump the lens slightly to try to dislodge the dust and move it to a better location off the glass?

[FredG]

I agree. I'm a firm believer in do-it-yourself, but I wouldn't dismantle a lens, especially one with AF and IS.

[Dan'O]

I just purchased a new Canon 30D & a new canon 17-55mm f.2.8 is lens. Before I used the lens I looked inside the new lens, no dust, perfect. Used it for two days and I noticed a tiny spec inside the lens if you look inside from the front of the lens. I was in shock! My lens filters and lens hood have not arrived yet and couldn't wait to use the camera and was taking pics of my 2 year old where he got tired of me taking pics of him and decided to spit/splatter all over the front of the lens as I was trying to do a close up on him! lol.. I immediately ran to get my clean micro fibber cloth to clean the outside of the lens. Before doing so I looke inside the lens once more to see the tiny spec still there in the lens.. I finishing cleaning the out side of the lens with the micro cloth and I go and look into the lens and my jam drops!!! now there are FOUR! specs of dust inside the lens!!! one is more than a spec its big Flake!! right in the middle of the lens inside!! How on earth does that happen??!! Some thing I did? I'm in awwwww!? Should I have never of used the lens before I got my lens filters and or hood on it??? I realize that it doesn't impare the quality of the photo's but knowing that I have 4 specs of dust inside my lens in less than 3 days of use is disturbing!...