topic Re: EF 100-400 IS II USM in EF & RF Lenses

EF 100-400 IS II USM

CliveM — Thu, 23 Nov 2017 15:36:04 GMT

I have not had this lens long but have an issue with the autofocus. If I extend the lens fully to 400mm it does not focus at all. Having recently been on a wildlife holiday where there were many 100-400mm lenses it appears I am the only one with this issue. If I first pre-focus on shorter length it focuses OK then, and focuses when fully extended. This can't be right can it? Any thoughts before I return it to Canon?

Re: EF 100-400 IS II USM

diverhank — Thu, 23 Nov 2017 15:44:58 GMT

It doesn't sound right at all. There is one thing to try:

On your camera menu, look for a magenta one...if there is an option called "Lens drive when AF impossible"...make sure that's set to ON which means the camera will continue focus search even when it thinks AF is not possible. I find that the camera is not very smart it often thinks AF is impossible when it really is possible and just sits there doing nothing.

Re: EF 100-400 IS II USM

Waddizzle — Thu, 23 Nov 2017 15:53:56 GMT

@CliveM wrote:
I have not had this lens long but have an issue with the autofocus. If I extend the lens fully to 400mm it does not focus at all. Having recently been on a wildlife holiday where there were many 100-400mm lenses it appears I am the only one with this issue. If I first pre-focus on shorter length it focuses OK then, and focuses when fully extended. This can't be right can it? Any thoughts before I return it to Canon?

Is this your fist super telephoto zoom lens? What camera body, and AF focusing mode, are you using?

Using a super telephoto zoom can take a little getting used to, especially one that has focusing range switches. Changing your focus from seven feet to seventy feet can tax the limits of your gear. Remember, while the lens focuses, it is the camera body that controls the process, and that YOU control the camera body.

Sometimes when I am making a significant change of focusing distance, I will refocus in steps. Instead of going from seven to seventy, I may focus on something halfway, or maybe two somethings, lite at 15 feet and then 30-40 feet. I find this is frequently needed when I switch the focusing range switch, although not always.

Re: EF 100-400 IS II USM

ebiggs1 — Thu, 23 Nov 2017 15:55:00 GMT

"This can't be right can it?"

No, it isn't but that doesn'tmean it is the lens' fault.

"Any thoughts before I return it to Canon?"

Yes, I do. Two things to do first, One is reset your camera and try it outside on a sunny day. Set the mode to P, ISO 400, AWB. Make sure the lens is set to AF and the limiter off. Second, try it on a different camera. Repeat the 1st suggestion.

If either of these work, there isn't anything wrong with the lens. If neither works call Canon service.

Re: EF 100-400 IS II USM

CliveM — Thu, 23 Nov 2017 16:26:50 GMT

Dark here now in the UK so will try your suggestions first thing in the morning, even if it is snowing! Can you explain what you mean by the limiter? I can't find a reference to this in the manual.

Thanks for the prompt reply earlier.

Re: EF 100-400 IS II USM

Waddizzle — Thu, 23 Nov 2017 16:30:10 GMT

@CliveM wrote:
Dark here now in the UK so will try your suggestions first thing in the morning, even if it is snowing! Can you explain what you mean by the limiter? I can't find a reference to this in the manual.
Thanks for the prompt reply earlier.

He is referring to the focus range switch. It “limits” the useable range of focusing distance, which allows for better focus resolving.

Re: EF 100-400 IS II USM

CliveM — Thu, 23 Nov 2017 16:33:23 GMT

Thanks for the reply. The body is a 5d mk4, and I have had many, many years of success with 28-300 and 30-350 in the past.

I have had to follow the step by step focus to get a sharp image at 400mm but the key point is 7 other similar lenses on a recent trip did not have this issue. Shooting wildlife, especially birds, this is not what I need. I usually leave the focus range on Full. Clive

Re: EF 100-400 IS II USM

CliveM — Thu, 23 Nov 2017 16:36:38 GMT

Thanks Hank. It was set to off, so that is something else to try in the daylight tomorrow. Sometime it is not just the camera that is not too smart! Clive

Re: EF 100-400 IS II USM

Waddizzle — Thu, 23 Nov 2017 17:03:52 GMT

@CliveM wrote:
Thanks for the reply. The body is a 5d mk4, and I have had many, many years of success with 28-300 and 30-350 in the past.
I have had to follow the step by step focus to get a sharp image at 400mm but the key point is 7 other similar lenses on a recent trip did not have this issue. Shooting wildlife, especially birds, this is not what I need. I usually leave the focus range on Full. Clive

I only use the Full setting for closeups. The lens will focus faster and sharper with the 3 meter to infinity setting, on more distant objects. This could be half the problem.

The other half of the problem could be AF setting in the menus that you found. But, if you have no problems with other lenses, then maybe not.

One last potential problem is a lens filter. I used to use a B+W UV filter, and my photos always seemed a little soft. I switched to a “Clear” filter, for protection, and I have been razor sharp ever since. I use a clear protective filter on all of my lenses.

Re: EF 100-400 IS II USM

Waddizzle — Thu, 23 Nov 2017 17:20:09 GMT

@CliveM wrote:
Thanks Hank. It was set to off, so that is something else to try in the daylight tomorrow. Sometime it is not just the camera that is not too smart! Clive

The 5D mark IV has complex focusing system. It work just as hard for you, as it can against you. Others have posted links to special manuals on just the AF system.

I use AI Servo mode, with all of the AF points active, on my cameras bodies. The AF points visibly track and move with subjects. There are a variety of tracking modes you can use. I have it set to always begin from the center AF point, and then use surrounding AF “assist” points as needed.

Then there are the priority settings, focus priority or shutter priority. I use Focus Priority for all of them. And, there is more. It’s too complicated to describe all settings here, just what it looks like in the viewfinder.

Re: EF 100-400 IS II USM

diverhank — Thu, 23 Nov 2017 17:20:42 GMT

@CliveM wrote:
Thanks Hank. It was set to off, so that is something else to try in the daylight tomorrow. Sometime it is not just the camera that is not too smart! Clive

Ha ha...it's just the camera. Not sure if this will solve your problem but everything is worth a try. I can tell you two things:

1. My day job is as a test engineer. One thing I learned is that it's always the one you least expect (that would never happen) that will get you every time. Things work for one lens do not mean they will work the same for others...

2. I didn't read about this setting...I learned it the hard way. I have a 5D3 and a 7D2 and both would occasionally and inexplicably quit focusing from time to time when I use the telephoto lenses (400mm f/5.6L, 600mm f/4L) - always at the most inopportuned time - until I discovered this setting. Since I set this to ON, I haven't had any problems. I got the 100-400 II after I set this option and I've got no problems with it whatsoever so I don't know if this could be the culprit. I can tell you that there is no downside to setting this option to ON.

Re: EF 100-400 IS II USM

CliveM — Fri, 24 Nov 2017 09:31:52 GMT

Tried it out this morning - did not work. Also tried it with the other suggestions about the range - this made no difference either.

Appreciate the suggestions though - it still might be operator error!!

Re: EF 100-400 IS II USM

Waddizzle — Fri, 24 Nov 2017 10:41:22 GMT

@CliveM wrote:
Tried it out this morning - did not work. Also tried it with the other suggestions about the range - this made no difference either.
Appreciate the suggestions though - it still might be operator error!!

What shooting mode are you using? And, what exactly does "did not work" mean? What exactly did you try to do?

Re: EF 100-400 IS II USM

CliveM — Fri, 24 Nov 2017 11:19:15 GMT

I tried it in P, Aperture and Speed priorities.

First I set the lens to be out of focus manually on a distant object, then extended the zoom to 400mm and tried to get it to autofocus. When I say it did not work - it did not focus at all. I have the camera set on A1 Servo, tried it on Full range and on 3m to infinity.

Putting the lens onto a 5DI it focussed everytime in the same modes as with the failures with the 5D4.

I still think it might be another setting and I will try going through all the settings on the 5D4 to see if there is something I have overlooked.

Re: EF 100-400 IS II USM

Waddizzle — Fri, 24 Nov 2017 13:33:31 GMT

You seem to have a direct issue with your one camera body. Contact Canon Support. The camera needs to be checked, and perhaps the lens, too. But, most definitely have the camera checked by Canon, and only Canon.

Re: EF 100-400 IS II USM

CliveM — Fri, 24 Nov 2017 14:09:07 GMT

Many thanks - still working through the settings before contacting canon. Appreciate all the advice received so far.