Focus help

[Dare1325]

I've had my 10D for over a year now and I've loved it. A family friend asked me to take some pictures of their bride and groom before the wedding. I shot about 140 pictures and about half of them were way out of focus. This has never happened before. In FVU I turned on the focusing point indicator and found that all these out-of-focus shots should have been in focus. I've never had this problem before and I'm quite concerned. I've posted a sample photo at http://home.comcast.net/~dare17

I was shooting in Aperture-Priority with my Canon 50mm lens at f1.8, shutter speed was 1/2000, in auto-focus. This particular photo the flash was off, but that did not seem to matter. There were many with the flash on that were just as out-of-focus. The sample picture was cropped to reduce file size and I added the red square to show where the focus point was set. I don't know if this is the best way to show a sample of what is going on or not, so if I need to do something different, please let me know, I'm not an expert at posting on forums.

Any help or advice would be greatly appreciated. If it was one picture I wouldn't worry, but since it was about 50% of them, I'm concerned. I hope it is something I've done rather than a camera that is acting out of sorts. Thanks in advance!

[robertwgross]

First of all, your sample photo seems to show a back focus problem. That may be from the camera body, from the lens, or a user problem.

Let's see if we can eliminate the user problem. You said 1/2000 shutter. That is pretty fast, so we can rule out camera shake. I don't think the bride was shaking that much, and it looks like strictly a hardware problem.

Next, if it were me, I would slap another Canon EF lens onto the same camera and see if the problem still exists. That should pin it down to either the lens or the camera body. Just to play on the safe side, get a test subject to stand up the same way, and then have them hold a high contrast target for you to aim at. I don't think that is absolutely necessary, but you never know.

If you figure out that it is likely to be a camera body problem, then you can send it to the Canon service center and they can recalibrate it.

---Bob Gross---

[Belmondo]

Were you in single shot mode or AI Servo?

Do you have the EXIF data for this shot?

[Dare1325]

Forgot to mention earlier that I was using a tripod. Camera was in AI Focus (not AI Servo). I was shooting RAW so I have the EXIF data, but I hate to say that I don't know how to get to it, other than in FVU. Enlighten me on that one and I'll get for you.

[WestFalcon]

As a wedding photographer with 10D's, the first thing that I would do in the future is to normally shoot at F5.6 or a smaller F-stop.The depth of field is extremely small at f 1.8 and any error on your part is going to get you blurry pictures. 10D's have been known to have focusing problems as some on the forum have pointed out. Thus, F5.6 or F8 gives you some room for error and some better depth of field. I rarely shoot anything larger than F2.8 and I don't have problems. I assume you are using the middle square and turn every other focus point off which I think is the best thing to do. Some people use the middle point and focus right in between the bride and groom at the background so you need to learn how to hold your focus point. If you are already doing this, you may have a defective camera or lens so try a different lens or send both in to Canon to get them checked. Good luck ..Brian