Sick of 5D mkIII auto focus issues

So having convinced myself to stay with Canon, I went out with the family today to a public garden, took loads of photo's, and looking at them now about 80% of them are out of focus.

I've MF'd all my lenses, bought software to do it, pre made focus targets, bought the best glass out there, yet my keeper ratio is just garbage. At one point today I was pointing the camera at my lad who was running towards me, BBF activated, central 5 AF points selected and square on his chest, he stopped about 8 feet from me, and the auto focus did nothing for about 5 seconds, I was just sitting there thinking WTF looking at the out of focus image doing nothing, until he turned around then it kicked in, to take another out of focus shot. I shouldn't be in the position of spending £8K on gear to have rubbish shots so many times, It's downright embarrassing if the missus is looking over my shoulder when I'm going through the shots on the PC at home. The ones that are in focus are great, but when they're so rare, what's the point......

So back to looking at mirrorless to get away from the out of focus shots, yes they're slower to focus, but I'd rather wait for focus to hit and get one good shot than 10 out of focus shots from my DSLR....

welshwizard1971 wrote in post #18430240
So having convinced myself to stay with Canon, I went out with the family today to a public garden, took loads of photo's, and looking at them now about 80% of them are out of focus.

I've MF'd all my lenses, bought software to do it, pre made focus targets, bought the best glass out there, yet my keeper ratio is just garbage. At one point today I was pointing the camera at my lad who was running towards me, BBF activated, central 5 AF points selected and square on his chest, he stopped about 8 feet from me, and the auto focus did nothing for about 5 seconds, I was just sitting there thinking WTF looking at the out of focus image doing nothing, until he turned around then it kicked in, to take another out of focus shot. I shouldn't be in the position of spending £8K on gear to have rubbish shots so many times, It's downright embarrassing if the missus is looking over my shoulder when I'm going through the shots on the PC at home. The ones that are in focus are great, but when they're so rare, what's the point......

So back to looking at mirrorless to get away from the out of focus shots, yes they're slower to focus, but I'd rather wait for focus to hit and get one good shot than 10 out of focus shots from my DSLR....

Unless I missed it, you don't mention that you had it on AI Servo. If he was running toward you and not in servo its not going to keep focus, which I know you know.

If this is as bad as you say.....something's wrong. Obviously that hardware should return a high keeper rate. But then with 5 focus points activated it's possible that it grabbed something else to focus on.

Sorry yes, 'AI servo', always is with the kids. I never use 'AI focus', it's either 'One Shot' for static stuff or 'AI servo'. It was so obviously bad I took ten minutes out to go through all the AF settings, but nope, nothing amiss....

I'll post some examples tomorrow....

This is precisely the reason I'll never shoot on a DSLR again....the critical focus accuracy just isn't there and it has nothing to do with settings. Separating the image sensor and the AF sensor is always going to have some deviation.

I stopped using DSLR's even when my best option at the time was MF on the original a7R, because even that was more consistently accurate with focus peaking.

mystik610 wrote in post #18430541
This is precisely the reason I'll never shoot on a DSLR again....the critical focus accuracy just isn't there and it has nothing to do with settings. Separating the image sensor and the AF sensor is always going to have some deviation. ....

With MFA, this is no longer true. With today's cameras you can adjust the lens to be in perfect focus.

OP, if your getting a 80% miss rate, I would evaluate your technique before looking at the hardware. THe 5DIII AF is pretty decent and 80% sounds over the top.

gjl711 wrote in post #18430552
With MFA, this is no longer true. With today's cameras you can adjust the lens to be in perfect focus.

OP, if your getting a 80% miss rate, I would evaluate your technique before looking at the hardware. THe 5DIII AF is pretty decent and 80% sounds over the top.

My last DSLR was the 5DIII, and even with MFA it was very much an issue. It depends on what your tolerance to critical focus errors are....as a portrait shooter who often uses fast apertures on long lenses, it was a big deal for me.

The problem with MFA is that it assigns a single value to a deviation the varies depending on a number of different factors...subject distance, color temperature of ambient light, the part of the frame (because the deviation isn't necessarily the uniform across the frame). The Sigma dock goes a step further by allowing you to assign different MFA values for different focus distances, but it still doesn't fully correct the underlying issues that exist when you stick a mirror in between the image sensor and the AF sensor. Like the OP, I used to obsessively MFA lenses using FoCal and or the dottune method, and the MFA value varies depending on the shooting environment. It's a frustrating and time consuming process that never fully corrects the issue, and I don't have to go through that any more. I also don't have to take multiple exposures of the same shot so I can pick the most in focus one later.

Also, eye AF basically ensures that you nail the eye every shot.

arthurbikemad wrote in post #18430258
Maybe look at your case scenarios, move the shutter priority to focus. My old 5D3 was an awesome camera, personally I would never change from such a camera to a mirrorless, unless it's an A9 anyway I now shoot with a Mk4, it's not a massive leap up from the Mk3, the Mk3 is a supurb action camera, I used to get fast action shots with my Mk3 daily, never heard anyone slate the AF so poorly, perhaps it's a duff.

Shutter Priority was in 'focus', one of the things I checked on my 'time out'.

Aghhhh rats, I went through the batch this morning, processed the ones I liked, saved them, then in auto pilot deleted the duff ones, forgetting I wanted to put some examples on here, so that doesn't help, sorry.

Having calmed down and reviewed them, it was probably 40% failure rate, still way too high, with all the failures moving targets in AI Servo, but being generous to the camera it was slightly shaded, but not dark, and the shutter was set as slow as I could get away with at 1/200 to compensate for being dark but maintaining a half decent DOF to keep them all in focus, maybe that was too slow for the kids moving around, but then they weren't sprinting, and the surroundings aren't in focus either. Also, when it did work, they were in focus at 1/200, with slight motion blur to a leading leg or hand, certainly not to the body or face, so 1/200 should have been fine. However, I did manage to get this one, 1/200 f5 ISO1000 70mm. It was in auto ISO to try and keep the ISO as low as possible with the main parameters of SS and DOF being manually set.

This was the last of a sequence of him running towards me, about 7 shots, this was the sharpest and I liked his expression so I kept this one, not exactly one to be proud of, this is SOOC. As you can see, all soft, nothing in focus front to back, motion blur to his leading foot, but even his planted foot is OOF.

IMAGE LINK: https://flic.kr/p/XSzL​h6

welshwizard1971 wrote in post #18430684
Aghhhh rats, I went through the batch this morning, processed the ones I liked, saved them, then in auto pilot deleted the duff ones, forgetting I wanted to put some examples on here, so that doesn't help, sorry.

Having calmed down and reviewed them, it was probably 40% failure rate, still way too high, with all the failures moving targets in AI Servo, but being generous to the camera it was slightly shaded, but not dark, and the shutter was set as slow as I could get away with at 1/200 to compensate for being dark but maintaining a half decent DOF to keep them all in focus, maybe that was too slow for the kids moving around, but then they weren't sprinting, and the surroundings aren't in focus either. Also, when it did work, they were in focus at 1/200, with slight motion blur to a leading leg or hand, certainly not to the body or face, so 1/200 should have been fine. However, I did manage to get this one, 1/200 f5 ISO1000 70mm. It was in auto ISO to try and keep the ISO as low as possible with the main parameters of SS and DOF being manually set.

This was the last of a sequence of him running towards me, about 7 shots, this was the sharpest and I liked his expression so I kept this one, not exactly one to be proud of, this is SOOC. As you can see, all soft, nothing in focus front to back, motion blur to his leading foot, but even his planted foot is OOF.

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double your shutter speeds for the sake of testing, and if you consistently get soft images at that rate, then you can be certain it was focus issues.

since you mentioned 70mm, you shouldnt have much issues with the lenses you have in that range, both very good focusing lenses. I'de expect at least 90% hit rate....

Took about 60 pics of them baking this afternoon, so not moving at 1/125 but still using AI Focus, every single one pin sharp. My AI focus can't seem to handle things that are moving? Unless I'm expecting too much, would you guys expect to get them all in focus if a 2yr old was waddling his way towards you in half decent light?

What I was sort of hoping to hear

welshwizard1971 wrote in post #18431023
Took about 60 pics of them baking this afternoon, so not moving at 1/125 but still using AI Focus, every single one pin sharp. My AI focus can't seem to handle things that are moving? Unless I'm expecting too much, would you guys expect to get them all in focus if a 2yr old was waddling his way towards you in half decent light?

Who the heck uses AI focus? Does it even work?

Stick with AI servo, and if you're shooting kids, micro movements will get you, raise the shutter speeds until you iron out your focus issues. Shooting F2.8 with top lenses, you shouldnt have much issues with focus.

Sorry, I meant AI Servo, see my earlier post

Can't see the shots and not sure what lens and settings but looks more like case of camera operator rather than the camera. Have 5dmk3 and not many issues. The mirrorless are better for things. I can even get more in focus shots when someone coming at me using my Fuji XT1 compared to my 5dmk3. On sideways, 5dmk3 much better. On single shots, mirrorless are more accurate though slower to AF in general.

I'm having a really tough time focusing subjects moving towards me, for instance our running dog. It may be due to my technique or the lens (135 f2), which I'm going to send in for calibration, as it also misses focus on non-moving subjects randomly. Concerning the technique I'm really wonderin how other people do it to get a high keeper rate.