5D3 AI Servo faulty?

Hey everyone. I'm having some difficulties with my 5D3 in AI servo mode and I am wondering of anyone else out there has had a similar experience.

The shortest story that I can make of it is that no matter what I do my keeper rate in AI servo with the 5D3 is seriously below what I can get with my 7D. I have used all the modes and tweaked all the setting but generally speaking the camera will not keep focus on my subject. More often than not focus jumps to the background (fence, buildings, etc.). I have tried several experiments with slow moving traffic and I get similar 'jumpiness' in this and similar scenarios which should prove fairly easy for any AI servo. If I focus on a static subject and just pan the camera I get similar results as well.

I gave it a lot of time because at first I thought it was just part of the learning curve but now I am convinced that there is an issue with the camera or, at least convinced enough to send it in to get checked. I would be interested in knowing if anyone else has had a similar issue with the 5D3 (or any recent Canon body for that matter). I'm also wondering what could be causing this. It would seem to me that AI Servo would be something that would either work fine or not work at all.

I'm very interested in what you folks might have to say.

Thanks!

SLKPhoto wrote in post #15054971
Hey everyone. I'm having some difficulties with my 5D3 in AI servo mode and I am wondering of anyone else out there has had a similar experience.

The shortest story that I can make of it is that no matter what I do my keeper rate in AI servo with the 5D3 is seriously below what I can get with my 7D. I have used all the modes and tweaked all the setting but generally speaking the camera will not keep focus on my subject. More often than not focus jumps to the background (fence, buildings, etc.). I have tried several experiments with slow moving traffic and I get similar 'jumpiness' in this and similar scenarios which should prove fairly easy for any AI servo. If I focus on a static subject and just pan the camera I get similar results as well.

I gave it a lot of time because at first I thought it was just part of the learning curve but now I am convinced that there is an issue with the camera or, at least convinced enough to send it in to get checked. I would be interested in knowing if anyone else has had a similar issue with the 5D3 (or any recent Canon body for that matter). I'm also wondering what could be causing this. It would seem to me that AI Servo would be something that would either work fine or not work at all.

I'm very interested in what you folks might have to say.

Thanks!

UnTweak them-- You must have stuff set to fast or incorrect. This 5D3 has one of the best AF systems on the market. Go back to base settings and shoot with those and modify when you really understand the system and how it works......It doesnt need a lot of tweaking.

OMG this is a huge coincidence. I'm a 7D owner for 2.5 years here, and 135 f2 for a year, and I've shot tens of thousands of photos with my camera. It recently started acting up and behaving in (what I interpret) the same erratic way as your camera does. What lens(es) are you using with the camera?

I just posted my original thread 2 days ago: https://photography-on-the.net …/showthread.php​?t=1232248

Basically, I'm getting the same weirdness that I've never seen before on my 7D in the past 2+ years. And that AI Servo makes focus 'jump' and backfocus. I've tried everything from changing and experimenting with various settings and updating the firmware of my camera to no avail. I got my 7D from Canon Asia with a 3 year warranty so I'm not sure if I can send mine in to Canon USA to get whatever's broken fixed.

When shooting couple of football games with 5dmk3 and 300mm f2.8 IS I, I notiecd that AF had a tendency to grab the focus on back fences. THis happened couple of times even when my AF points were clearly on the target but camera grabbed fence way way in the back. Now I had slow setting on the tracking senstivity (forget the case number as I don't have the camera any more). Maybe I should have changed that to fast.

Post some shots and let us see what is happening.

I'm not the OP but here's an example I posted yesterday:

"OOF - OOF - Sharp - Tack sharp - Sharp - OOF. During the times where the shots are OOF, you can see the floor behind the player is in focus.

This behavior doesn't just happen in continuous shots. I could fire off one or two photos and there's now a high chance that one or both are OOF, despite my AF point being dead center on the subject.

http://imgur.com/a/Zea​hu"

I've shot too many volleyball games in the same venue/lighting using the same settings to know that this behavior is abnormal. Despite the subject not being dead center in the frame, I have my AF set to the center 9 cluster and my 7D has never had issues being 'distracted' by background or subjects in the rear before, up till this week.

I was suspecting my lens (135 f2) or my 7D's firmware (recently updated to 2.0.0 then 2.0.3; but it happened in both cases) so I'm going to go ahead and speculate that it's a hardware issue. Anyone in with me on this? Something might have gotten loose or one of the connections is faulty perhaps?

umphotography wrote in post #15055095
UnTweak them-- You must have stuff set to fast or incorrect. This 5D3 has one of the best AF systems on the market. Go back to base settings and shoot with those and modify when you really understand the system and how it works......It doesnt need a lot of tweaking.

Good advice Mike, thanks. I've already tried this however and I also performed a hard reset of the unit without any change.

EOS Man wrote in post #15055125
OMG this is a huge coincidence. I'm a 7D owner for 2.5 years here, and 135 f2 for a year, and I've shot tens of thousands of photos with my camera. It recently started acting up and behaving in (what I interpret) the same erratic way as your camera does. What lens(es) are you using with the camera?

I just posted my original thread 2 days ago: https://photography-on-the.net …/showthread.php​?t=1232248

Basically, I'm getting the same weirdness that I've never seen before on my 7D in the past 2+ years. And that AI Servo makes focus 'jump' and backfocus. I've tried everything from changing and experimenting with various settings and updating the firmware of my camera to no avail. I got my 7D from Canon Asia with a 3 year warranty so I'm not sure if I can send mine in to Canon USA to get whatever's broken fixed.

OK well at least I know I'm not alone. I would be very interested in the results if you do send it it for service. It is really strange. Like yourself I'm not a newb when it comes to photography, DSLR or AI servo but I have to admit that the fact this is a new system really has me questioning myself at times. I would love to get my hands on another 5D3 to do some comparison shooting.

bobbyz wrote in post #15055132
When shooting couple of football games with 5dmk3 and 300mm f2.8 IS I, I notiecd that AF had a tendency to grab the focus on back fences. THis happened couple of times even when my AF points were clearly on the target but camera grabbed fence way way in the back. Now I had slow setting on the tracking senstivity (forget the case number as I don't have the camera any more). Maybe I should have changed that to fast.

Post some shots and let us see what is happening.

Interesting. I could post some shots but I'm not sure they would provide any insight as to what is happening. For instance, I was playing with the dog this afternoon. He's about 125lbs so he makes an easy target. He reached the end of the yard and was making a medium paced trot back directly toward me and the camera could not stay on him. and kept moving to the fence behind him. I can repeat this scenario with any pre-programmed AI servo setting tweaked any way. So basically what you would see is a huge out of focus dog and a nicely focused fence. This is the same thing I get when trying to track anything. I tried several mornings unsuccessfully to track seagulls down by the shore. The focus kept moving away from them sometimes just to the sky. I can reproduce this with cyclists, pedestrians, cars, etc.

How does your AI Servo work on static subjects?

If you select a single AF point, keep Servo running continuously and shift the AF point from background to subject to foreground and back again - does it refocus swiftly and consistently? Does the behavior change if you swap lenses?

Also, have you the latest firmware (1.1.3) installed?

agedbriar wrote in post #15055514
How does your AI Servo work on static subjects?

If you select a single AF point, keep Servo running continuously and shift the AF point from background to subject to foreground and back again - does it refocus swiftly and consistently? Does the behavior change if you swap lenses?

Also, have you the latest firmware (1.1.3) installed?

Thanks for your input. I do have the latest firmware installed and I have been able to reproduce this on every lens I have tried.

When I use the AI servo in the manner you describe the camera does function as one would expect it to. Similarly the camera is fine when used in one shot AF. However, when I use all focus points the camera is easily fooled even by static subjects. By this I mean if I focus on a telephone pole with nothing else of contrast or that the camera should be interested in the camera will lose focus if I pan the camera left/right in any manner (fast, slow, erratic) no matter how the AI servo settings are configured.

Yeah, i have to say I see the opposite. my 5D III woops my 7D. It does seem to take tweaking. I was playing with the settings and made it just horrible for a while (for what I shoot, motorsports) but I went back to close to the OEM settings and it was great.

I am a little confused by the problem you are having, maybe I am just using my camera different? I select the one single focus point I want to use and it stays focused on whatever I have it pointed at.

chopperdave wrote in post #15055649
Yeah, i have to say I see the opposite. my 5D III woops my 7D. It does seem to take tweaking. I was playing with the settings and made it just horrible for a while (for what I shoot, motorsports) but I went back to close to the OEM settings and it was great.

I am a little confused by the problem you are having, maybe I am just using my camera different? I select the one single focus point I want to use and it stays focused on whatever I have it pointed at.

Hey Dave. I hear what you are saying and yes, from what you have described you and I apparently use AI servo differently. I can use AI servo as you use it and get a very high keeper rate as well. The thing is for what I shoot I rarely get the luxury of being able to use that configuration. I would never be able to keep the subject on that single focus point so I use an expanded area selection mode such as zone AF of the entire 61-point area. These are modes that I am familiar with and use effectively with the 7D for birds in flight and quick moving subjects such as small mammals, etc. that are tough to keep centred and/or steady on the viewfinder.

I have set zone AF to "not selectable", don't trust the camera to select the point for me.

With the entire 61 point Servo, you have to first select one AF point with which you have to acquire the initial lock on subject, before the other points start taking over in succession, as the subject shifts across the frame.

The PDF from bottom of page, left, is great:
http://www.learn.usa.c​anon.com …ebook.shtml?cat​egoryId=12

BTW - My keeper rate is still pretty high overall. Haven't used 7d only 1dmk2 and 5dmk3 is lot better AF wise.

Maybe you need to select ferwer points. That is why I asked for sample shots to see how much of the frame being filled with the dog.

Also never use all points unless shooting BIFs in clear sky IMHO.

bobbyz wrote in post #15056231
BTW - My keeper rate is still pretty high overall. Haven't used 7d only 1dmk2 and 5dmk3 is lot better AF wise.

Maybe you need to select ferwer points. That is why I asked for sample shots to see how much of the frame being filled with the dog.

Also never use all points unless shooting BIFs in clear sky IMHO.

With the dog it is a pretty dynamic thing as he may be 50 feet or 10 feet away at any moment. It doesn't really make a difference in terms of reliability whether he fills 10% or 50% of the frame though. I guess it is time to ship this baby back