[enoxatnep]

I shot a number of photos at a wedding this past weekend, thank God not as the main "pro" but as a relative to the bride and groom who was asked to get shots from a different perspective, because I was horrified to notice a number of them with faces slightly/moderately out of focus!!

At first I was pretty distraught, but after much examination I noticed that it was those shots where the background (mostly trees) was close behind the subject/subjects. When the background was farther away, focus was almost always perfect.

Here's what I suspect: When I had set my AF point on the face/head of the subject, it's as though the camera got confused and locked onto the background or somewhere in between, resulting in the OOF faces. This was most apparent when more zoomed out and the AF square covered more than just the face. For the record, I used SEL to manually choose focus points on my K-5 using the DA 16-50* and the DA 50-135*.

So my question: What tips/articles can anyone provide to get focus to lock on the faces instead of the background when it's right behind my subject?

[jatrax]

One the common complaints about the k-5 was the rather larger AF 'points', they are not points but rather areas. Anything within that area is a potential target. So, as you discovered if the AF area covers both a face and something in the background that has more contrast to it the camera may decide the background is a nicer target and select that.

There is no easy answer (that I ever found) but you can do a few things to help. First, understand how big the AF areas are and try to focus with that in mind. Another trick I often used was to focus twice, focus, wait for the beep and then hit the focus button again. This resulted in a significantly higher number of keepers at the expense of having to take longer for focusing.

Just being aware of the issue and using caution when focusing goes a long way to help though.

[asp1880]

You can also focus on the torso. It's usually in the same focus plane as the face and it's a larger and sometimes more contrasty AF target.

Regards,
--Anders.

[Oldbayrunner]

https://www.youtube.com/playlist?list=PLeu1p5jL9GOMp6eXmAcXIASb8UE98_kO4

https://www.youtube.com/playlist?list=PLeu1p5jL9GOP03BfkI80Pl2rt3TQ050lj

[aleonx3]

I am just curious whether you have set the shooting mode in AF.C instead of AF.S? And also if you use AF button on the back to lock focus (obtain focus confirmation) it would still be in focus even if you move slightly to recompose.

[adwb]

At wedding in the church where you are a long way from the couple and the minister is in the shot and you are using a wide apature and therefore shallow depth of field is a good case in point for this problem.

I zoom in far tighter than I want for the shot and with the back button set to focus and continuous on , focus then zoom out and I find that works 95 % of the time.

I have shot dozens of weddings with 2 x k 5 bodies and assorted lenses and there are always a few that are out. If thy are critical add some grain and b/w them and often that will make them acceptable.

It's surprising that what we think is a reject image due to your problem the couple are happy to accept. I normally dump them out of professional pride but for a collage page in a album where they are small images they often also can be usable.

[enoxatnep]

I am just curious whether you have set the shooting mode in AF.C instead of AF.S? And also if you use AF button on the back to lock focus (obtain focus confirmation) it would still be in focus even if you move slightly to recompose.

I did have it set to AF.C and I do use the back AF button. However, I found many times I was accidentally flipping the switch back to AF.S when I would change from landscape to portrait orientation and vice-versa. (A finger would accidentally flip it.) Then I would wonder why the AF was fussy until I noticed this problem. Something about the K-5 that I never noticed until the wrong time!

---------- Post added 08-09-2014 at 09:56 AM ----------

You can also focus on the torso. It's usually in the same focus plane as the face and it's a larger and sometimes more contrasty AF target.

I zoom in far tighter than I want for the shot and with the back button set to focus and continuous on , focus then zoom out and I find that works 95 % of the time.

These are great tips! I'll definitely try these out.

[TER-OR]

AF-S, focus on the bodies then recompose keeping the focus locked. Or just crop the photo later.

Another option is to switch to manual. I have to do this in the field all the time, mostly when shooting dragonflies. Green/brown dragonfly on green stem in front of green background - the camera gives up (dude, I have no idea what I'm trying to focus on). So the body switch back to manual, quick focus adjustment and expose. That on-body switch is great.