# Canon 24-105mm and 100mm lenses with impurities



## shinyknights (Dec 17, 2011)

Hey guys,

Is it normal for my canon L lenses to have impurities? I just got them 2 weeks ago. I never bothered to check til now when I was using a rocket blower on it. I bought a 5D Mark II with 24-105mm f/4.0 L kit lenses and a 100mm f/2.8 L macro lens.

I have pics of it. Would the impurities cause chromatic aberrations? I'm wonder what step I should take next. Return the items to BH Photo Video for a new set? Or send them to canon to get the lenses element replaced?

I have pics of them both. The 24-105mm has a spec behind the front lens element. The 100mm has a spec somewhere in the middle. I'm kinda bummed. I just dropped so much money onto these lenses.

www.shinyknights.com/24105mmF4L_1.JPG
www.shinyknights.com/24105mmF4L_2.JPG
www.shinyknights.com/100mmF28L_1.JPG
www.shinyknights.com/100mmF28L_2.JPG
www.shinyknights.com/100mmF28L_3.JPG

Any help is really appreciated.

- Jeff


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## pwp (Dec 17, 2011)

What is it we are exactly looking at here? Sometimes reflections can fool you. 

If the imperfections are real and present, take the lenses back to your retailer and discuss. If the lenses are faulty, a changeover will probably be a simple matter. Don't delay a minute!

If you bought second hand, test the lenses and you'll probably find their performance is well within critical limits.
If they are not up to your standards, sell them again. You'll barely drop a penny.

Paul Wright


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## Mt Spokane Photography (Dec 17, 2011)

I did not see anything but dust and reflections. Dust is normal. It used to be common for tiny bubbles to be in the high quality glass, it was considered to be a mark of high quality, but most of the time, modern processes for molding glass no longer forms them.


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## lol (Dec 17, 2011)

I assume the "problem" is the bright white speck on both of these lenses? Can't tell 100% from the photos, but I'd guess that's most likely dust, which is perfectly normal. If you ever use a lens, some will find its way inside sooner or later, no matter carefully you try to prevent it.


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## EYEONE (Dec 17, 2011)

Doesn't look like anything I would worry about myself. When I got my 70-200 it had a white speck like yours that I worried about for a while. It didn't affect the images so I became less consider after a few weeks. Then I realized it was on the back element and I simply wiped it off. With all that glass sometimes is hard to tell where it is.

As with most things, Roger helps us out. http://www.lensrentals.com/blog/2011/08/the-apocalypse-of-lens-dust


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## bycostello (Dec 17, 2011)

dust probablly but if new just take them to the dealer and i'm sure they will clean them up for you


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## JR (Dec 17, 2011)

I agree if you can check back with the dealer. I would suspect that you dont see those dust in your picture right? Since the lens focus point is further then the end of the lens you should be ok. I had a dust like this in one of my L lens but it was stuck more into the middle blades and while I could see it it never impacted the image quality. If however you see those "impurity" in your shots and you are confident they are the source, go back to your dealer, if not, it is not as bad as you think...good luck


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## xROELOFx (Dec 17, 2011)

when you buy a lens new, it should be completely dust free. if you take it out of the box and there's dust on the glass or inside the lens, it could have been used before, or maybe brought back by another customer.
this happened to me once, i just went back to the store and asked for another one. my first thought was they screwed me with a used lens, selling for the price of a brand new one. fortunately they gave me another one wich was completly clean and dust free.


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## shinyknights (Dec 18, 2011)

Yea, I'm sorry for the pictures. The outside is actually really clean. There is only one spec on the inside. I'm not sure if its a bubble or a dust particle. But I really need to get one of those camera lens napkins to clean the outside. I've only used the rocket blower on it, and it doesn't quite blow all the dust away. I'm using the lens without filters too cause I read about how they only affect your image quality and give you more glare, so I use the hood instead.

Each of the lenses, 24-105mm and 100mm each have a spec on the inside of the lens, which bums me out cause it's supposed to be weather sealed, considering it's an L lens.


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## pwp (Dec 18, 2011)

shinyknights said:


> I'm using the lens without filters too cause I read about how they only affect your image quality and give you more glare, so I use the hood instead.



It's considered just about universally that best practice is to screw a filter on the front...UV is fine. 
Just make sure it's decent quality...I'd be amazed if you could pick the difference. You have dropped a lot of $$ on your new lenses, it's far cheaper to replace a UV filter that you don't mind cleaning with your shirt than a damaged front element. 

Like the Nike advert...just do it.

Paul Wright


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## shinyknights (Dec 18, 2011)

I agree with you on the UV filter. I just gotta educate myself more about it. I know so little about filters. I'm leaning a bit towards B+W or the Hoya. Friend's got the Hoya. It's amazing how he says that you can still fit both the lens cap on the Hoya and even able to mount the hood onto the lens without ever taking off the filter.

BH Photo Video's got the multi-coated, thin, and wide filter.
And of those filter, there are so many types such as UV standard, UV 415, UV 420. Does the number really matter? There are the UV Haze 2A, 2B, 2C, 2E too. Many, seems like I'm about to spend another grand or so just on accessories.


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## xROELOFx (Dec 18, 2011)

shinyknights said:


> But I really need to get one of those camera lens napkins to clean the outside. I've only used the rocket blower on it, and it doesn't quite blow all the dust away. I'm using the lens without filters too cause I read about how they only affect your image quality and give you more glare, so I use the hood instead.
> 
> Each of the lenses, 24-105mm and 100mm each have a spec on the inside of the lens, which bums me out cause it's supposed to be weather sealed, considering it's an L lens.


yeah, the blower does not always blow away every dust particles, so a good napkin/cloth (is this the correct word?) is needed to eliminate the sticky ones.

remember that, while most of the L lenses are being marketed as weather sealed, they still need a filter on the front before they are actually so.

so like pwp already mentioned, it is a good thing to get a good quality filter. i myself use only hoya hd filters. they are really good and easy to clean, but can be pretty expansive.


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## neuroanatomist (Dec 18, 2011)

"B+W UV Haze 010 F-Pro MRC" is what I'd recommend. 77mm for the 24-105, 67mm for the 100L Macro.


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## pp77 (Dec 19, 2011)

Just for my understanding, if a zoom lens like the 24-105 is extended it needs to soak in air to compensate for the increase in volume in the lens tube. Is there a kind of air filter which prevents dust from being soaked in? If not, it is probably not possible to keep the lens interior dust-free over the long term?


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## neuroanatomist (Dec 19, 2011)

pp77 said:


> Just for my understanding, if a zoom lens like the 24-105 is extended it needs to soak in air to compensate for the increase in volume in the lens tube. Is there a kind of air filter which prevents dust from being soaked in? If not, it is probably not possible to keep the lens interior dust-free over the long term?



Dust is pretty much inevitable over time. But the zoom rings of sealed extending zooms are fitted with O-rings and brushes which serve to keep the dust to a minimum.


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## Mt Spokane Photography (Dec 19, 2011)

Dust happens, the first time you use it, you could suck dust into it. It generally does not cause a issue if it is in the front. If its on the rear element, it should be cleaned off.

I usually only have a lens cleaned when I go to sell it, because buyers unnecessarily worry about dust. When I sold my 17-55mm, it was dust free after three years of use. Its the only one of my lenses that always had a UV filter installed.


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## Axilrod (Dec 20, 2011)

He may be talking about some of the tiny bubbles that you see in the glass?
I think thats actually a sign of quality glass...
How do the pictures look? If good, don't worry about it. 

The likelihood that you ended up with 2 different bad L lenses in the same order is slim to none.


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