canon 100-400 f4

Due to the push pull design of the canon 100-400 F4 IS does this cause more dust to collect on the sensor of a DSLR.

You will encounter people who claim that the lens is more prone to dust because it is being sucked into the crevices of the lens while zooming the lens out. Personally i think it's a load of crap...but then i've never owned the lens.

In either case, the lens doesn’t put your camera in any more harm then any other lens...

I solve this problem buy not pumping the lens in and out while under my sofa...

Really I've never found it to be a problem.. but I don't shoot in areas filled with dust bunnies at eye level often.

I guess we are discussing the Canon EF 100-400mm f/4.5 to 5.6 L IS lens.

We might have a discussion about whether the push-pull design will get dust into the lens structure. However, I don't think that is going to affect dust getting onto the camera's main image sensor, which is behind the shutter.

---Bob Gross---

Or more importantly...behind the rear element of the lens.

I read an awful lot of comments about the pumping of dust. Some of it sounded like people justifying why they don't like this way of zooming. I wondered about it because I was getting ready to buy it. The thing is, if it is going to pump dust, it is going to bring it into the lens, not into the sensor which has a nice element at the back of the lens in the way. I may be wrong (and often am) but I think it is a red herring. By the way, I eventually bought the lens and love it.

Push-Pull, Shmush-pull - any lens that expands and contracts is susceptible to inhaling dust, regardless of how it is actuated. I think this is a legend that grew some legs.

I do think it is time for Canon to update this lens, and hopefully they will do away with the push-pull when they do. In the meantime, don't get to concerned about the dust issue - if you like it, get it.

Have Fun,

I have the 100-400 and never seem to have any problems.

When I push, it sucks the dust in. When I pull, it blows the dust out. The trick is to remember that for every push there must be an equal and opposite pull. This final pull not only helps expunge the dust, it makes the lense shorter and therefore easier to stow away.

I agree... If a lens can be extended, it's prone to sucking in dust.. It doesn't matter if you extend it by pulling it out directly, or twisting a ring.

I have one completely unscientific and unproven observation that I've noticed with the lens...

I was getting a considerable amount of dust on my sensor prior to purchasing my 100-400.. After I started using the lens, it seems I don't have nerar as much problem with sensor dust..

Could the air movement caused by the lens be cleaing out the mirror/shutter area of the camera

I'be been around photography long enough to remember when a "one-touch zoom" was the latest and greatest in zoom techonology. It was hailed as a great advance over the "two-touch" zoom that required you to zoom with one ring and focus with the other. The advent of autofocus pretty well negated the concept since a two-touch zoom could still be controlled with one ring while the camera controlled the focus. I've used both for over 40 years and both are just about as likely to pull dust into the lens. If the lens is constructed properly, as is the 100-400, the dust problem is minimal and will not exagerate the likelyhood of dust on the sensor. They are remote from each other and mutually sealed from exposure to one another.

Just as a side comment, if you're considering the 100-400 you can't go wrong! I've used most major types of zooms - Nikon 80-200, old Vivitar one-touch zooms, the Sigma 50-500 and 120-300, Tokina 80-200 AT-X Pro - you name it, I've probably used it or something very similar to it. You will not beat the 100-400L! It focuses fast, it's quiet and sharp as the proverbial tack. I personally love the push-pull (one-touch) construction and find it much faster than a twist ring to zoom.

Hope this helps.

Dave H.

Bob and Timmy,

the 100-400mm rear lens element is not fixed,. it too moves front to back during zooming,. and is not in any way sealed,. there is space around the rear element which dust can and will get around and into the camera body,. at ehich point with air movement possible and in fact likely ,. dust can and will find it's way around a shutter as well.

However,. Like CoolToolGuy says,. this is true of most zooms no matter what the method used to zoom,. This coupled with the fact that one must get dust into the lens beofre it can be pushed into the camera.. makes this lens no different from most zooms as far as dust potential is concerned, despite it's push pull design.

There are some Zooms that have a fixed sealed rear element,. like Canon's EF 70-200mm f/2.8 IS (and perhaps Timmy's non IS?) ... but this is not "the norm" these are Canons weather sealed lenses.

I don't notice any more dust using the 100-400 L lens but that might be because I only use it in an environmentaly sealed clean room and only when I'm wearing a clean suit. Kind of limits what I can shoot and I have yet to be able to use the 400 end but at least I don't have to worry about dust.

Don't worry about it! You'll get no more dust with that lens than any other ... it's a great lens!

Why did I waste that money on a rocket blower, all I had to do was zoom my lens faster.... Oh well you live and learn.

N

The copper hill kit cleans the sensor . . . shoot away and don't worry about what will happen anyway. I love my 100-400, btw.

I really like the push/pull design and I haven't had to clean my sensor yet.