EF 24-70 f/2.8L II: How much clearance of the zoom ring?

[yeahright]

Dear Forum!

Just the other day I noticed some clearance when zooming my 3-month-old Canon EF 24-70 f/2.8L II. That is, I turn the zoom ring in one direction and then reverse the direction. Then, before the barrel actually starts to move I can slightly turn the zoom ring (by about half a millimeter at the perimeter) without anything happening. So in any position I can turn the zoom ring back and forth by this half millimeter without any actual zooming. Is this within standard tolerance limits?
Otherwise the lens works just fine.

Many thanks
Markus

 

[Mt Spokane Photography]

Its likely that there is some wear of the internal guides that move the zoom. If it bothers you, send it to Canon for repair. If its in warranty, definitely send it in.

 

[yeahright]

Its likely that there is some wear of the internal guides that move the zoom. If it bothers you, send it to Canon for repair. If its in warranty, definitely send it in.

It bothers me only if it's not supposed to be that way. The effect is not really restrictive because the clearance is rather small. That's why I'd like to ask whether others' copies show the same effect. If that tolerance is supposed to be zero, then I'd rather have it checked/repaired/replaced. Since I bought it new only 3 months ago and have really not used it much there can't be much wear yet.

 

[Mt Spokane Photography]

Mine is a few years old and does not do that, neither do any of my other zooms. Having play like that can be a pain for zooming in / out on a subject.

 

[Loswr]

My 24-70/2.8L II has no play when changing zoom directions.

 

[slclick]

No play on mine, sorry.

 

[LSXPhotog]

Its likely that there is some wear of the internal guides that move the zoom. If it bothers you, send it to Canon for repair. If its in warranty, definitely send it in.

It bothers me only if it's not supposed to be that way. The effect is not really restrictive because the clearance is rather small. That's why I'd like to ask whether others' copies show the same effect. If that tolerance is supposed to be zero, then I'd rather have it checked/repaired/replaced. Since I bought it new only 3 months ago and have really not used it much there can't be much wear yet.

I can assure you that it's not supposed to be that way. I would send it into Canon to have it repaired when you have a chance. The zoom collar should be a 1:1 movement and have no slop, as with all other Canon lenses.

 

[mjg79]

Mine doesn't have any "slip" either.

However if it's working I suspect it's not a problem. A while back on fred miranda a poster there explained how he bought a 35L II and found the focus ring was a bit loose "up and down" and he sent it to canon who said it was within specs. He researched it and it turns out that various parts of the lenses are designed with some margins which then allow the lens to be calibrated when it is being built as a technician will be able to select various parts of varying thickness (such as the mount) to ensure correct infinity focus etc. So some variability is inevitable.

If it's easy to send it somewhere to get it checked it might not be a bad idea but I wouldn't get too worried right now.

My 24-70 II after a few months of ownership started to have a little play in the zoom barrel itself, only very slight but I noticed it, would also make a slight rattle if gentle shaken where it didn't when I first bought it. I was a bit concerned at any play so sent it to Canon who duly checked it and found it was all within specs and now some years later it's still never caused any problem.

I think it's easy to obsess over these small things really but we must remember that everything has tolerances built in otherwise it would require manufacturing processes where every stage is absolutely perfect all the time which isn't really possible unless we want to pay $100,000 per lens.

 

[yeahright]

Thanks for all your answers! I now definitely will at least have it checked, since it's still under warranty.

 

[mrmarks]

So in any position I can turn the zoom ring back and forth by this half millimeter without any actual zooming. Is this within standard tolerance limits?
Otherwise the lens works just fine.

Many thanks
Markus

I have checked the zoom rings in my 24-70 L2 and my 70-200 L2. There is a slight "free play" in the zoom barrel before the internal mechanism is engaged, approximately half mm as you mentioned. This is normal and nothing to be worried about. It certainly does not effect the function and performance of the lens.

 

[yeahright]

Before sending my lens in I went to the store where I bought it and had a look at another new copy of the lens, whether it had the same play on the zoom ring, and in fact it did. Just like mine. So maybe both are from a batch with larger play. Or others that have reported no play for their lenses in this thread didn't consider that minor play noteworthy. Another way to put it is: When I engage the zoom lock switch, I can still turn the zoom ring slightly, about that mentioned half millimeter.
I will now probably not send the lens in after all.

 

[aceflibble]

Having some minor play in a zoom or focus ring is very normal, as well as minor play in the lens mount. It's obviously less and less common the higher up in lens quality/price tag you go, but there will always be slight variations.

It becomes especially noticeable in winter months as parts contract; each part may only contract a tiny fraction of a millimeter, but when all the parts do that, it adds up.
For example, my old 400mm is quite 'loose' in many regards right now. A couple of the switches don't click into place as firmly as they did a couple of months ago and on my older 7D it shifts in the mount slightly. Generally, about 1/3rd of my gear feels as if it's more cheaply-made between November and March, while between the end of June and the middle of September, everything fits very snugly.

A little play in an L lens is not unheard of, and in most countries this time of year, I would not be surprised to see it become quite obvious.

 

[hne]

For a mechanical engineering description of the source of and countermeasures to this "clearance", have a look at https://en.wikipedia.org/wiki/Backlash_(engineering).