Canon EF 100-400mm Push Pull Zoom

[obelix]

I'd like to know, from anyone owning this lens, preferably for more than 2

years already with a bit of usage.

I heard that after a couple of years or maybe less, the lens's zoom mechanism

starts to go slack. So when the lens is mounted on your camera & it faces

downwards, it will slide out all the way?

I don't know if I've asked the question right, but I hope you understand.

 

Also, any known dust issues with the push/pull zoom? (I'll be returning to

South Africa at the end of the year, after being in a very dust free Ireland

for 4 years)

 

I hope someone can help, as I'm about to buy one

 

Thanx Guys

[marknagel]

There is a tension ring to adjust the friction or lock the lens. You should aways be able to adjust it enough. I've had mine a year and it was bought second hand. I think the lens is 3 years old now.

 

m

[lamoine_einspahr]

I have owned a 100-400L IS for 3 years. I have the opposite problem with the push-pull. I snug up the clamp a bit for storage, and when I get into some fast action, I cannot change the zoom fast enough. When set to the loose position, it is easy to use in fast action. It is the best lens I own and the images continue to astound me both in resolution and contrast. When I read of distractors complaining of soft images I wonder what they are comparing it to. I have never had a problem with it sliding open when the clamp is adjusted properly. My best advice is to buy from a store that will allow you to test for image quality and allow you to exchange if your lens does not exhibit the image quality I described. I have had the "poor copy" problem with another Canon lens. Luckily, I received a good quality Canon lens the second time around.

[christsloan]

I have also had the lens for about 3 years with no problem like you mention. If you are shooting is dusty situations dust is just part of life. Personally with any IS lens I would buy and extended warranty. If you have any problems they could get very spendy. So spend a little more money and be covered for a longer period of time. Canon only gives you one year. Mack is a great company for extened and would probably clean if you get dust.

 

On that lens you have a loose and tight. It does not slip as far as I have ever heard from anyone.

[steve_dunn2]

<p>Perhaps I can add a question for those who own this lens. I've played with it four times in stores and at photo equipment shows (and I'm pretty sure that at least two of them were different samples of the lens), and every one has had the same problem: the zoom torque adjustment ring and the focus ring tend to bind together. That is, if you turn one, the other one tends to turn as well, even if you're very careful to make sure your fingers are only touching one of the two rings.</p>

 

<p>Do you find the same thing with yours, or have I somehow managed to find multiple examples with a problem which is not representative of this lens in general?</p>

[robin_sibson1]

Steve, that's how it's MEANT to work - rightly or wrongly! The zoom stiffness (not torque - it's a push-pull zoom) ring piggybacks on the focus ring and it is adjusting it RELATIVE to that ring that alters the stiffness. With the stiffness at minumum the lens slides entirely freely under its own weight, even from new - or, at least, mine did - and at the other extreme you can lock it solid.

 

I have had one of these lenses since they first reached the UK, and have done many safaris and similar trips with it, using it first on a 1V, optionally with the Extender 1.4x, and now on a 20D almost never with the Extender. I regard it as good but far from perfect optically, but for my needs there is no other lens that offers such a good compromise. Never had any dust issues.

 

I did however have one major issue that is a design weakness of this lens, which is that the ball-bearing mechanism that supports the moving part of the lens can collapse after a significant period of use. Repair is straightforward, but that does not mean cheap.

[john_macpherson]

Steve - they are designed to do that. You can set the tension by turning the friction ring, and the focus ring will turn too. Not a problem. Neither is dust. I have had a 35-350 for over 10 years of hard use in all conditions, and no dust, also had a 100-400 for a spell and no dust. That well respected L lens the 24-70 is also a push/pull (except you rotate it to extend it) and no-one ever complains about that lens filling up with grit. Unless you use it in unbelievably grotty conditions and abuse it terribly you wont have a dust problem. Great lens, sharp and fast to use.

[steve_dunn2]

<p>Thanks for the answers. It seems like a bizarre way to do it; there's no logical correlation between focus distance and how much force should be required to change the zoom position, and thereforethe two rings really ought to be physically disconnected since they perform completely unrelated functions. But it's hard to get a really good idea for how a lens handles when just playing with it briefly; I'm glad to hear that it's not a problem in the real world.</p>

 

<p>(I replaced my 300/4L IS  with the 70-200/2.8L IS USM after I went from film to 1.6-crop 20D. I don't think it's likely that I'll go full-frame, at least not in the foreseeable future, but if I do, I'll need a longer lens again. I won't want to give up the fantastic 70-200, so I'd probably end up getting the 100-400. That's why I wanted to know.)</p>

 

<p>Thanks again.</p>

[obelix]

Well I'm glad both me and Steve Dunn got our answers.

It just makes me spending the money on the lens so much easier, after reading everyones comments.

 

Hopefully I'll have it in the next month!

 

Thanx

[derek_hammond1]

Steve, I don't think you've quite grasped the point!<p>

The Friction ring is mounted ON the Focusing ring, when the focus ring is turned the Friction ring will turn with it as it is attached to it.<p>

In order to adjust the zoom resistance the Friction ring must be turned RELATIVE to the Focus ring. I.E. turn the Friction ring whilst holding the Focus ring stationary.<p>

The resistance to zooming is NOT related to the focusing distance! <p>

If this sounds awkward rest assured it is not, it is quite easy to adjust zoom resistance with one finger whilst holding the focus ring and looking through the viewfinder.

[andy_jones2]

Johann, One of your questions was not answered completely but by inference only :-) If

*you* forget to readjust the friction, let's say after zooming out to 100mm, and then point

the camera down, the barrel *will* slip out to 400 on its own. You will just need to

develop the habit quickly of checking that it's sufficiently tight - a few clunkkks of it

happening will surely help - but it's no different than other habits one needs to develop as

a photographer. There are some who say it's "soft" wide open at 400 but I think the one I

had (before I sold it to fund the 500/4) was OK, because some came out sharp and some

didn't. I recommend you practice bearing in mind that the IS needs some time to settle

down and that if you press the shutter all the way too quickly, you'll get blur as a result.

Press half-way and wait till the VF image settles down, then expose.

[steve_dunn2]

<p>Derek, I do understand. It just makes no sense to design the lens this way. There is no logical connection between focus distance and zoom stiffness, so there's no reason the controls for the two should be linked like this. Canon doesn't design two-touch zooms where the zoom ring and the focus ring are linked like this.</p>

[robin_sibson1]

Steve, although I have learned to live with the way the stiffness control works over the years, I have always thought it was a very strange design choice. I can't imagine why you would WANT it to work like that! However, the fact that you can connect up electronic controls any way you like (or, at least, the manufacturer can) should not make us forget the ingenuity required to lay out mechanical controls well. Take a look under the hood of one of the last great purely mechanical cameras like the F-1 to see what I mean. Just getting shutter speeds from 1 to 1/2000 evenly spaced on the same dial is a serious engineering feat. So it is just possible this arrangement for the stiffness control was the best Canon could devise. I think it works the same way on the other two big push-pull zooms (35~350 and 28~300).

[andy_jones2]

Steve Dunn , jun 14, 2006; 02:01 p.m.

Derek, I do understand. It just makes no sense to design the lens this way. There is no

logical connection between focus distance and zoom stiffness, so there's no reason the

controls for the two should be linked like this. Canon doesn't design two-touch zooms

where the zoom ring and the focus ring are linked like this.

 

Steve, They are linked only in the sense that they are both physically on the same object -

the one that moves back and forth as you zoom in and out. IF you change the focus

distance, you do not affect zoom stiffness and vice versa - so they are not functionally

linked. Where else, other than on the moving part of the barrel, could you put the control

for the zoom stiffness - or for that matter, the focus ring? Where do you want them? BTW

the two touch zooms don't have a zoom stiffness control that I'm aware of. How would

you redesign this push-pull zoom (and "convert it to an internal zoom" is not an

acceptable answer :-) - it would probably make the lens permanently as long as the fully

extended barrel! )

[ockert_lombard]

I have just recently aquired a 100-400L lens and doesn't have much experience with it. Before buying it, I have spent a lot of time on the internet to read more about the lens. I have found that a lot of the early postings (3-4 years ago)on many of the web sites were about the tensioning ring on the lens getting stuck. This is apparently when the many very small bearings in the mechanism gets dislodged and then gets stuck between the moving parts. It is then very difficult to zoom the lens and sometimes even impossible to do it. I must admit that the recent postings on this lens does not make any mention of this problem. I have found that if the tension is not set correctly and you point the lens downwards or upwards that it slides to the end with a horrible "clonk" sound which can't be very healthy for any mechanism. I am sure that one must be very careful that this doesn't happen. I am eager to hear if any one else has experience about this problem lately?

 

Thanks

Ockert