topic Re: Sudden autofocus problem on 5D Mark III in EOS DSLR & Mirrorless Cameras

Sudden autofocus problem on 5D Mark III

sdhweb — Mon, 13 Jul 2015 21:41:43 GMT

Hello, I have a nearly two years old 5D Mark III with only 7800 images taken. The camera has been working well and I've been happy until now.

Yesterday I experienced that autofocus would not work on an easy target. I thought 'what the heck is going on?'... After that incident I keep having this problem. Sometimes autofocus seems to work and sometimes it seems to do nothing at all. The focus confirmation light and the AF status indicator is just flashing.

I use the AF-ON button for focus and the IS is leaping to action but the autofocus doesn't seem to be doing anything. I experience this on contrasty subjects in full daylight. And suddenly it may be working again but it seems very unstable. I haven't done any changes to the settings before this started to happen.

It seems to be worse when I change back and forth between focusing on something close and something far away. If I manually adjust the lense very much out of focus it seems to have a very hard time to get back on track. Mostly it fails. If I then help it quite a bit and manually adjust the lense more in focus it suddenly works again.

I've always had the setting 'Lense drive when AF impossible' set to OFF and I've never had these problems before. Changing this setting to ON seems to 'help' a little, it at least changes the behaviour of the autofocus. With this enabled in seems to at least be trying (and more often succeed) instead of just doing nothing. Keep in mind that I'm talking about good and easy autofocusing conditions here, not low light situations.

Conciderations:

1. I have tried two different lenses with the same result (EF 70-200 F4L IS USM and the EF 100 F2,8L IS macro)

2. I have cleaned the lense contacts on both the body and the lense.

3. I've upgraded from firmware 1.2.3 to 1.3.3 and reset the camera to factory settings.

4. I've changed focus back to the shutter button

None of the above actions have made any difference to the situation. I've had this camera for nearly two years and something has definitely happened. The camera is very well treated and have no visible damages.

Any advice on this one?

Re: Sudden autofocus problem on 5D Mark III

TCampbell — Tue, 14 Jul 2015 01:46:17 GMT

Which focus type are you using? (Spot, single point, expanded area, surround, zone, or full 61 point auto-select?)

Which focus mode are you using? (One-shot, ai-focus, or a I-servo?)

Re: Sudden autofocus problem on 5D Mark III

Peter — Tue, 14 Jul 2015 04:07:08 GMT

Dust at the AF sensor is also possible. It sits under the mirror.

Re: Sudden autofocus problem on 5D Mark III

sdhweb — Tue, 14 Jul 2015 06:55:51 GMT

Ahh, I forgot to write that this happens in both One shot and AI servo (AI focus not tested). I've always used the center focus point alone.

Re: Sudden autofocus problem on 5D Mark III

sdhweb — Tue, 14 Jul 2015 18:14:23 GMT

Hi,

Thanks for the response. I've tried to clean it by using a blower with the mirror up, but it looks very clean inside. After the cleaning I took about 1000-1500 images, mostly of flying seagulls and thought the autofocus was OK. But right before it was time to go home it failed again. I had just focused on a stone 2 meters away, and then when I tried to focus on the mountains in a distance it just fails. It cannot focus. There is plenty of light and contrast.

I have done the same test several times during todays testing and it worked every time so I really thought the cleaning did the job. But failure again right before I was going home 😞

So I guess I need to send it in for repairs...

Re: Sudden autofocus problem on 5D Mark III

JonKline — Tue, 14 Jul 2015 18:29:39 GMT

Any time I have any Canon issues, I don't hesitate to send it in for repairs. Unlike certain other camera brands that start with N, Canon's turn around time for repairs is WAY faster. Usually it's less than a week to get everything back to 100%

Re: Sudden autofocus problem on 5D Mark III

sdhweb — Tue, 14 Jul 2015 18:45:55 GMT

I hope you are right JonKline. I live in Norway so it may be different here, not sure. I think we have less options/shops to choose from since we are a much smaller country.

The worst thing that can happen, that I fear, is that they'll send it back and say they don't find any errors. Hope that not happens because something i clearly wrong.

Re: Sudden autofocus problem on 5D Mark III

sdhweb — Sun, 30 Aug 2015 19:19:56 GMT

Hi all, I'm sorry for the late reply here. It took the shop over 4 weeks from they received the camera till they actually started working on it. They blamed it on summer vacation 😉

It only took them a day to repair though once started. The AF-sensor had gotten shifted out of it's calibrated position (no clue how that happened) and it had to be recalibrated and then the AF had to be adjusted. They said the camera needs to be impacted for the sensor to 'move'. I don't know how this may have happened since I'm very careful with my gear, but I'm glad the problem is fixed 🙂 Thanks

Re: Sudden autofocus problem on 5D Mark III

sdhweb — Sun, 08 May 2016 18:24:17 GMT

Hello again, one more question here if I may... My camera has worked well since the repair but today I tried to shoot some macro which I haven't done in a year or so.

Is it normal that the camera cannot focus on something 'further' away right after I've focused on something very close? I've hold the camera very close to for example a flower and focused on it. Then I move the camera and point at my foot which is 1 meter away. When I look in the viewfinder it's all very blurry because it's out of focus. Nothing strange with that but the camera is not able to focus, even on normal contrast subjects.

Is this because the focus is so much to the macro end that it's hard to find subjects in a more normal distance? Or is it my camera again? (If I help the camera and focus manually till it's almost in focus then autofocus find focus again.)

The lens I used was EF 100mm f/2.8L IS USM

Re: Sudden autofocus problem on 5D Mark III

ed_vatza — Sun, 08 May 2016 20:05:15 GMT

First check the obvious. I believe you have a control on the lens that lets you select focus range. It goes from

1' (.3m) - 1.6' (.5m)
1.6' (.5m) - ∞
1' (.3m) - ∞

Make sure it is not on the

1' (.3m) - 1.6' (.5m)

or you won't be able to focus on your foot.

Easy to forget to switch it after using in a extreme closeup situation.

Re: Sudden autofocus problem on 5D Mark III

SR71Norm — Wed, 07 Mar 2018 22:27:36 GMT

I am having this very same issue. I have always kept my camera secure and clean. Apparently from the reply threads below this is an item that must be repaired by canon. Does anyone know if this is an issue that is covered by their warrany program or not? Is there perhaps a recall on this? Thank-you.

Re: Sudden autofocus problem on 5D Mark III

sdhweb — Thu, 08 Mar 2018 19:36:12 GMT

You read the whole thread and understood what was the problem to my camera? After the repair it has worked flawlessly. I had to pay myself but the repair was not more than 180 USD which isn't too bad.

Re: Sudden autofocus problem on 5D Mark III

SR71Norm — Thu, 08 Mar 2018 20:34:34 GMT

Yes I did read all the threads. I understand that they told you that your camera's AF-sensor had somehow gotten shifted out of it's calibrated position and that you sent it in for repair and that they re-calibrated it and now it is all fixed. I also have taken very good care with my Canon 5d3 and cannot understand how this problem could have happened. I had noticed this issue for a while now, but since it was so intermittent I had not investigated it. To me it appears to be a manufacturer failure, but I have not found any recall on it yet. I guess I will have to "bite the bullet" and send it in for repair on my own dime. Pretty sure I did NOT cause this. Thanks for your info on this issue and I hope I have as good an outcome as you have.

Re: Sudden autofocus problem on 5D Mark III

sdhweb — Fri, 09 Mar 2018 06:25:18 GMT

No problem. I was in the same position as you. They said that the sensor had been shifted out of position and that this only can be caused by a physical impact. Like you I have no idea how this might have happened. I tried to argue with the service technician who told me that it was quite common for them to hear that 'nothing has happened' to my camera.

I just had to accept the fact that I do not have full control over the camera 100% of the time. For example when I keep it in a bag I can leave this bag unattended by me. There is a small possibility that the kids might have bumped into it and don't dare to tell me <shrugh>