24-70 2.8ii focusing issues

[gjones5252]

Hey i recently purchased a 24-70 v2 and I shot two weddings with it this past weekend. As i edit i am starting to have a lot of out of focus images. When i say a lot i mean in regards to this lens and camera combo.
The first area was when the bridal party was retreating down the aisle post ceremony and the first images of them are in focus but it's like the focus locks and does not change as they get closer to me. Very frustrating, but i thought well it could be me and some of them looked like they also could have locked between the people and then ignored possible distractions.

Second is when the pastor is with the groom pre ceremony and standing still. The very first shot was out of focus and stayed that way till about 7 pictures later. This was not a burst shot these were all new button presses.
In these images below you can see it is clear as day on the bark yet the people are out of focus, once it achieves focus its beautiful.
I thought at first it was due to the fact i didn't set it up with focal, but then it will achieve focus perfectly other times.
I dont even know how to troubleshoot this and i am nearing the end of my return window.

THis happened enough that i actually installed the add on to see where it had acquired focus. I havent had this many out of focus photos since i started.
Also first time adding photos. no idea if this is the right way....

 

[Loswr]

Done an AFMA?

 

[gjones5252]

No, that was my initial thought but if some are front and some are back focused could that still be the issue?

 

[Loswr]

There may be many issues. Are you using Zone AF or AF point expansion? That's useful with small/erratic subjects, but generally its a bad idea to let the camera pick your AF point. You are letting the camera decide whether your subject is static or moving, and that's also generally a bad idea (there's a reason 1-series bodies don't have the AI Focus mode).

Set up on a tripod with a flat, high contrast subject (newspaper taped to a wall), shoot 5 live view shots, 5 viewfinder AF shots, pick the sharpest of each set. If the live view one is visibly sharper, AFMA is recommended.

 

[gjones5252]

I use AF point expansion and not the Zone Autofocus.
I have read where people say the ai-focus was the best of both worlds. Now i just did a google search that is suggesting the opposite.
so then would Ai-servo be the best to utilize and then if i have stationary objects switch over??
During situations where it changes frequently(weddings, events) it would be very hard to go back and forth..
Good to know 1 series dont even have it.

 

[Loswr]

Consider back button AF: http://www.learn.usa.canon.com/resources/articles/2011/backbutton_af_article.shtml

 

[docholliday]

I have my X programmed so that the left back button is One-Shot AF, the middle back button (* button) is Ai-Servo, and the front-top Mf-2 button to switch to 61-pt AF. With those button combos, all I have to do is move my finger (or mash a set of buttons) to switch to modes on the fly. I can then let off all buttons to hold focus. I don't do too many weddings anymore, I can't stand them. But, when I do one (about 1-2 times a year), I use the same setup - left button for most shots. And move my finger over one button in case they start moving on me (processional/recessional).

During stuff like the dances, I will start with a single, center AF point left button. Move finger to the right if they are swaying. Mash the front 61-pt if the light is good and I want to track their face (the iTR actually works here!).

I think the 7D2 can do that custom buttons setup, I don't think the 5D3 can, though. (Never owned a non-1-series body).

No matter what, Zone AF is not good unless you have a small item, with fairly plain background - the algorithm is designed to get (what the AF perceives as) the closest object. In the case of a wedding, that's not good, as it may not be the face of the subject. Single point, center (or spot AF, center if needed) is the most reliable way to get the shot, especially if you are shooting shallow DOF stuff.

 

[gjones5252]

As i am continuing to edit this wedding i am getting more and more frustrated.
There is definitely something wrong as more and more of my photo seem to be off focus. I will use focal and do a AFMA adjustment.
I guess i was just under the impression that with that being the flaw that they would almost always be either front or back focused.

I am very interested in looking in to the back button focus and I read the article Neuro but am i still unsure what the difference is. It seems like it just gives you the option to separate the focus and shutter. Can you explain some good examples why this is the way i want to go?

The other part that confuses me is this has only happened since i received this new lens. No pictures taken with another lens have this issue.
After i do an AFMA would just putting the camera on a tripod and defocus then take a picture be the best way to see if there is an error?

 

[Loswr]

I am very interested in looking in to the back button focus and I read the article Neuro but am i still unsure what the difference is. It seems like it just gives you the option to separate the focus and shutter. Can you explain some good examples why this is the way i want to go?

If you focus/recompose, you can take multiple shots without having to refocus-then-move each time. You can set focus, then wait for the moment/expression, then release the shutter without having to hold in a half-press or wait for refocus. For remotely triggered shots the focus won't change. Those are a few of the reasons that come to mind.

The other part that confuses me is this has only happened since i received this new lens. No pictures taken with another lens have this issue.
After i do an AFMA would just putting the camera on a tripod and defocus then take a picture be the best way to see if there is an error?

I'd take a few pics. At this point, I don't think a defective lens has been ruled out.

 

[TGCorneliussen]

possibly defective as neuroanatomist stated the possibility of. i have not had such issues with my copy.