Dust in refurbished lens from Canon

[brianleighty]

Alright, so I ordered the Canon 70-200 f/4 L non-IS. Actually two as I did not realize I couldn't cancel an order and I had a 20% coupon that I wanted to use. Anyways, so I get both lenses and inspected them. The outside is fine other than some dust I was able to blow off with my blower. Looking through both of them though they both have a pretty good amount of dust in them. I'm trying to decide whether it's worth paying to ship it Canon to have them take it apart and clean it or not. I was hoping one would be clean at least and I could keep that copy but they both have it. I've taken some shots and I'm not seeing anything. Perhaps I'll have to shoot at f/22 at MFD and see if I can see it. I asked lens rentals their thoughts and this is what I got back in reply:

Its hard to say what you might be seeing without a visual but it sounds like either dust or cleaning residue. Most used or refurbished lenses will have a light to moderate amount of internal dust. If they aren't very noticeable, chances are they will never affect your images. There is also a good chance that Canon has opened up the lenses to be repaired at some point and left residue on the elements from cleaning them. This is not ideal, but again will probably never affect image quality. If you are uncomfortable with what you are seeing I would bring it to Canon's attention with some photos of the spots on hand.

I wanted to get everyone's comments on what they thought I should do. Thanks.

 

[ksagomonyants]

Even new lenses could have some dust inside them. If it bothers you, just return the lens. But as you were told, most likely it won't affect the image quality. I may be wrong but I guess most, if not all, zoom lenses will get some dust inside of them within a relatively short period of time.

Even my 200 f2 has some dust specs inside...

 

[mwh1964]

I would not worry about it.

 

[duydaniel]

It is up to you. But since you posted, I guess you want to return it.
So return it

 

[brianleighty]

It is up to you. But since you posted, I guess you want to return it.
So return it

Not necessarily. I just wanted some reassurance this is normal and I shouldn't worry about it. Thanks for the input everyone. I'm shooting a wedding this weekend. If I don't notice anything in the pictures from that I won't worry about it.

 

[neuroanatomist]

Good of lensrentals to answer. I guess they didn't point you to Roger's blog?

http://www.lensrentals.com/blog/2011/08/the-apocalypse-of-lens-dust

 

[ShootingStars]

If the focus is SPOT ON, the sharpness is great, etc. don't return a lens just because of dust... dust doesn't do anything.

 

[ksagomonyants]

Here's another extreme example of lens damage and dust inside the lens, and how it affects image quality

http://www.lensrentals.com/blog/2008/10/front-element-scratches

Good of lensrentals to answer. I guess they didn't point you to Roger's blog?

http://www.lensrentals.com/blog/2011/08/the-apocalypse-of-lens-dust

 

[brianleighty]

Here's another extreme example of lens damage and dust inside the lens, and how it affects image quality

http://www.lensrentals.com/blog/2008/10/front-element-scratches

Good of lensrentals to answer. I guess they didn't point you to Roger's blog?

http://www.lensrentals.com/blog/2011/08/the-apocalypse-of-lens-dust

Thanks. I read those before but it's been a while and for some reason I thought those were focused on a different aspect of things. The lens is sharp (tested against the 70-200 f/2.8 IS II and while a little bit behind held up well at f/4. The lens I'm returning is actually a TINY bit sharper than the other but I bought that one with the 15% off coupon so the $30 difference isn't worth it. Plus the lens I'm keeping is from this year so it also has the new Canon lens cap with the pinch in the center which I've to say I'm really liking much better. Thanks for everyone's help.