Not focusing on a light-skinned blonde on a sunny day

Yesterday I tried to photograph my daughter and her discus throwing partner at their conference track meet. It was a bright, sunny Colorado day. When I later reviewed the photos, none of the two dozen photos of my daughter were in focus, while all of the photos of her throwing partner were in focus. They were alternating throwing, so I don't think a camera setting changed during the shoot. The only explanation I've been able to imagine is that somehow the camera and lens are "not seeing" my very light-skinned, very light blonde daughter as an object to focus on, while the camera and lens have no problem "seeing" her medium brown-skinned throwing partner. This is not the first time I've encountered this "lack of focus" problem when photographing my daughter, and it always occurs outdoors and on sunny days. Frankly I am really baffled and hope that some of you who are vastly more knowledgable and/or experienced in outdoor/sunny day photography can help me find a solution and maybe even an explanation.

My camera is a Canon EOS 50D, and I'm using a Sigma 50:150mm 1:2.8 II lens. Both have been serviced and calibrated within the past 12 months.

Thanks for reading my post.

Nah, I just think her throwing partner had you in her spell

(but then again, total conjecture on my part, as in re-reading your post I noticed you did not say whether her throwing partner was female)

Well they're both pretty cute, but 68 yo fathers aren't supposed to say that about their 17 yo daughter's friends

Lol, not quite. But in your defense, it could have all been subliminal.

Throw up a pic or two. Perhaps there's something in the periphery that may have caused the odd focus behavior.

Could be something as simple as too low a contrast under the AF point, pale skin, pale hair and sunlight could result in a target that just has nothing on it dark enough to AF on. Her friend on the other hand, if she had dark hair, would provide better contrast between hair and skin.

Were you making a conscious effort to place the AF point over contrast or just pointing it at her face? Usually an eye will provide decent contrast, or failing that the hair line (although not necessarily in this case).

Here are three of each girl.
/Users/jimfred1/Pictur​es/IMG_9428.jpg
/Users/jimfred1/Pictur​es/IMG_9434.jpg
/Users/jimfred1/Pictur​es/IMG_9437.jpg
/Users/jimfred1/Pictur​es/IMG_9440.jpg
/Users/jimfred1/Pictur​es/IMG_9443.jpg
/Users/jimfred1/Pictur​es/IMG_9447.jpg

I hope these photos make it clear what the issue is. I am shooting in "sports" mode with the Canao, and autofocus.

Canon, that is.

jimfred wrote in post #15924761
Here are three of each girl.
/Users/jimfred1/Pictur​es/IMG_9428.jpg
/Users/jimfred1/Pictur​es/IMG_9434.jpg
/Users/jimfred1/Pictur​es/IMG_9437.jpg
/Users/jimfred1/Pictur​es/IMG_9440.jpg
/Users/jimfred1/Pictur​es/IMG_9443.jpg
/Users/jimfred1/Pictur​es/IMG_9447.jpg

You can't link to a file on your computer, you'll need to upload it somewhere so that we can see it.

Sandpiper probably gave you the best guess as to what may be happening but until we can see some images its hard to say for sure. Also what mode were you shooting in? What were the settings? If you cant attach the data you will want to provide that to us as well.

jimfred wrote in post #15924769
I hope these photos make it clear what the issue is. I am shooting in "sports" mode with the Canao, and autofocus.

OK, is "sports mode" one where the camera sets everything for you? (Sorry, but I don't use any full auto modes as they just screw things up for you, so know very little about them).

If so, I presume that the camera will be in "all-points" AF mode, so it selects which focus point to use? If you are using all-points AF, the camera will tend to choose a point with good contrast under it. That puts us back to the "not enough contrast" theory, but now the camera is simply choosing to focus on something else.

You may well have enough contrast in your daughters face, to get the AF to lock, but need to tell the camera specifically where to focus. Left to its own devices it will simply choose a higher contrast target and so focus on that, rather than your daughter.

Here is a url to several photos of each girl. Sorry it took me so long go get it here.

http://www.flickr.com …6/sets/72157633​474015361/

I think it was nailed above, but auto mode tends to make a mess of things.

Try use center point focus only, and start with Av and set ISO so you have at least 1/1000 ss. For best results go to manual exposure and set it so it gets the exposure of the subject and not the background. AI Servo will probably be best to use as well.

The majority of them (both girls) look out of focus to me, just some worse than others. Many shots seemed to be locking onto the fence. AI Servo using center focus point, and shoot in manual mode with at least 1/1000 shutter speed as stated above. Below are some good links that will get you out of automatic modes and help you use your camera to its full potential:
Introduction to exposure triangle: http://www.canonoutsid​eofauto.ca/learn/
Exposure simulator: http://www.canonoutsid​eofauto.ca/play/

Your focus with the blonde hair girls images were on the person in the lawn chair slightly up the hill and behind her.
You need to get out of Program mode and as mentioned set a single counterpoint focus point.