# Revisiting Dust Issues: ef 100-400mm f/4.5-5.6 L IS II



## YuengLinger (Mar 26, 2016)

About a year ago, there was a lensrentals article, I believe, posted in CR about dust in version II of the 100-400mm. I have been unable to find that article again, but lately, I've been getting a lot of dust on my sensor while or after using the lens.

I will say this is pollen season, and I generally make one or two lens changes in the field--but I'm quick and careful to reduce exposure to wind.

So, after some time in wide use, any others experiencing dust issues? I mean more than other lenses, not necessarily compared to version I, which I never owned.

And can anybody help find that article about how the new lens is not much better in terms of keeping dust out?

Thanks!


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## monkey44 (Mar 26, 2016)

I don't see it in mine - but live in a more humid climate, not so dusty. We do have pollen, but it has not been exposed to much of that yet this season. In addition, I don't change lens much in the field, as I carry the 7D2 and the 5DM3 with appropriate lens -- helps keep things a little cleaner. 

I shoot mostly outdoors, too.

It will get a dust-test soon enough tho', as we're heading to the SW USA in a month or so ...


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## AlanF (Mar 26, 2016)

I recall that the problem was internal dust in the lens. Dust gets in to the body only for those that are not weather sealed, with one reader posting it got through the battery compartment of his camera.


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## neuroanatomist (Mar 26, 2016)

Dust floating in the mirror box after a lens change could be blasted into the sensor by the action of zooming.


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## Maiaibing (Apr 5, 2016)

YuengLinger said:


> About a year ago, there was a lensrentals article, I believe, posted in CR about dust in version II of the 100-400mm. I have been unable to find that article again, but lately, I've been getting a lot of dust on my sensor while or after using the lens.



Dust is a problem for all lenses where the lens extends far and fast enough to create a certain vacuum/pressure. There was a lot of talk of the old 100-400 IS L being a "dust pump" with countless claims this was due to the push-pull action. Not so.

Instead it was due to air being sucked in/out when zooming and dust creeping along the extended barrel when extending/retracting. The II version has the same two challenges. Have not been able to play around with my version II yet, so cannot say if has the same amount of air flow as the old lens. The exposed barrel surface however is smaller which helps.

I shot the old version in one of the most dusty environments on the face of earth. Here I learned to wipe the lens barrel regularly, to keep zooming to a minimum and to only zoom slowly when needed. These three precautions kept dust down to an absolute minimum - almost none. If you have a problem you should try this.


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## Morris (Jun 6, 2017)

Maybe I'm the lucky one out of the millions. My 6 month old 100-400L II is collecting dust at the front element. Today I just sent it back to Canon for 2nd time service since the 1st RMA with same issue 3 months ago. I see that there are few same dust collecting complaint on the internet but not as much as the old version. This lens is claimed to have better weather seal and I am expecting Canon has already solved the dust collecting problem happened in the old push and pull version. Seems like it is not the case. One thing I really don't understand is: I used both this Canon 100-400 L II and Sigma 150-600 C (not weather sealed) in the same bird shooting environment, on the beach and in the wild, my Sigma lens never got dust into the lens after one and half year heavy use. I have clear filters and hoods on both lens all the time for protection. I ready don't get this. Otherwise, this is a fantastic lens for handheld wildlife shooting.


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## Keith_Reeder (Jun 6, 2017)

Maiaibing said:


> Here I learned to wipe the lens barrel regularly, to keep zooming to a minimum and to only zoom slowly when needed. These three precautions kept dust down to an absolute minimum - almost none. If you have a problem you should try this.



Yep, that's the trick - use the lens like a lens, and not like a be-bop jazz player's trombone.


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## HB (Jun 6, 2017)

I am on the point of sending my lens back to canon for a service as well, bought it just after it's issue and now find the front element to have an unacceptable amount of dust on it.
I once owned a very good draw tube telescope which suffered the same problem and wasn't adverse to removing the objective lens myself to give it a clean, remembering this I decided to test the ring holding the front element in and was dismayed to find I could move it very easily and wondered where the effective seal was.
I have to say that for the vast majority of the time I've had it there has been a UV filter in place which I would have thought enhanced the protection, that along with the fact the lens is very seldom removed from the body.


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## Sporgon (Jun 6, 2017)

I've become rather a prime lens user now, and I change lenses multiple times in poor conditions, yet I get nothing like the "dust" on the sensor that I used to when using an extending zoom and very little lens changes.


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## AlanF (Jun 6, 2017)

It was the CR mods who said they had dust trouble with their lenses just as they were getting out of the rental business. Just don't worry about it.


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## markesc (Jun 6, 2017)

You can always roll the dice and DIY:

http://photography-on-the.net/forum/showthread.php?t=1428149


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## [email protected] (Jun 7, 2017)

My 100-400 II is dusty enough to be called "furry." I keep meaning to send it in for a cleaning, but that would mean being without it for more than 12 hours.


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## JEL (Jun 7, 2017)

I've been using a Sigma 70-300 on a 5D3 for years and haven't noticed any dust-issues.

I'm about to replace that lens with the Canon 100-400II, so it'll be interesting to see if that will change (I doubt it, but time will tell of course)

I also use primes and do change lenses in the field.

Before 2011 I had a Sony mirror-less (A3 I think it was called. One of the first mirror-less they came out with that could change lenses). That machine was a dust-nightmare (not just dust, but big visible strings of hair showed up on images. Terrible camera. For some reason I've never seen that on the real DSLRs I've had. I can't say for certain if it plays a role, but I do think the mirror is a good thing actually. Of course the reason could be something else)


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## tomscott (Jun 8, 2017)

3 months across Africa had no problems. Mainly kept the 100-400 on my 7DMKII and had a 5DMKIII with standard lens attached. When I did change tried to do it somewhere sheltered. No problems here


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## YuengLinger (Jun 8, 2017)

Are the lenses with UV filters getting dust? Doesn't Canon claim that a filter "completes" the weather sealing? (Not sure if they use that exact word, but that's the gist, right?)


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## old-pr-pix (Jun 8, 2017)

Keith_Reeder said:


> Maiaibing said:
> 
> 
> > Here I learned to wipe the lens barrel regularly, to keep zooming to a minimum and to only zoom slowly when needed. These three precautions kept dust down to an absolute minimum - almost none. If you have a problem you should try this.
> ...


I've not had any issues so far with my Mk1 version following those suggestions. I prefer the push-pull design because it can be faster, but I try to not make use of that fact too often. Just be glad that Canon hasn't done the same thing Panasonic did for their 100-400 MFT lens. Panasonic wanted to avoid the dust issue as much as possible so they added extra sealing. The darn thing is so well sealed that it almost takes two hands to zoom more than a few mm. One needs to allow time for the pressure/partial vacuum to equalize before zooming further. Talked to Panasonic national rep. who told me it takes about 6 months of frequent use for it to wear-in fully!


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## neuroanatomist (Jun 8, 2017)

YuengLinger said:


> Are the lenses with UV filters getting dust? Doesn't Canon claim that a filter "completes" the weather sealing? (Not sure if they use that exact word, but that's the gist, right?)



They do use that term, but only for certain lenses – those with 'internally' moving front elements (i.e. the front element moves but that movement is all behind the plane of the filter threads). That short list includes several ultrawide zooms (the 16-35 lenses and 17-40) and the 50/1.2L. 

Canon USA's tech mouthpiece Chuck Westfall has personally recommended using front filters to help with sealing on all lenses that take them, but that language is 'officially' only applied to the lenses I indicated above.


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## LonelyBoy (Jun 9, 2017)

Maiaibing said:


> Dust is a problem for all lenses where the lens extends far and fast enough to create a certain vacuum/pressure. There was a lot of talk of the old 100-400 IS L being a "dust pump" with countless claims this was due to the push-pull action. Not so.
> 
> Instead it was due to air being sucked in/out when zooming and dust creeping along the extended barrel when extending/retracting. The II version has the same two challenges. Have not been able to play around with my version II yet, so cannot say if has the same amount of air flow as the old lens. The exposed barrel surface however is smaller which helps.
> 
> I shot the old version in one of the most dusty environments on the face of earth. Here I learned to wipe the lens barrel regularly, to keep zooming to a minimum and to only zoom slowly when needed. These three precautions kept dust down to an absolute minimum - almost none. If you have a problem you should try this.



I rather think you're contradicting yourself - the push-pull allows for faster zooming (it's one of the reasons people liked the push-pull!). As you pointed out, that makes the problem worse, so while all externally-zooming lenses absolutely can get dust, push-pull allows the user to make the problem worse than twist zooms, and that's close enough to "makes the lens a dust pump" true enough in my estimation. If you do use the push-pull slowly, then yes, it'll be as ok as a twist, but I'd be shocked if that were the norm.


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## Maiaibing (Jun 11, 2017)

LonelyBoy said:


> Maiaibing said:
> 
> 
> > Dust is a problem for all lenses where the lens extends far and fast enough to create a certain vacuum/pressure. There was a lot of talk of the old 100-400 IS L being a "dust pump" with countless claims this was due to the push-pull action. Not so.
> ...



Well, maybe I just push a little slower and twist a little faster than you do - but a normal fast twist of the new version creates a noticeable effect.


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