Back focus?

Mrs. Prout Has a CameraMrs. Prout Has a Camera Registered Users Posts: 93 Big grins
edited May 3, 2011 in Technique
I shoot on a Canon 50D - usually with my 24-70 f2.8 lens. Has anyone experienced any problems with back focus?

For example- If I place a person in front of a wall and stand a few feet in front of them and take a head shot- it will come out perfectly crystal clear with no blurring etc.

If I back up to about 8-10 feet away from the subject- suddenly I lose that sharp focus on the person, and the wall tends to be in focus instead.

I always make sure my focal point is center weighted and this even happens if I use a tripod.

Comments

  • SamSam Registered Users Posts: 7,419 Major grins
    edited May 3, 2011
    I am not clear on your statement, "focal point is center weighted", but try shooting on a tripod using only the center focus point.

    Sam
  • Mrs. Prout Has a CameraMrs. Prout Has a Camera Registered Users Posts: 93 Big grins
    edited May 3, 2011
    Sam wrote: »
    I am not clear on your statement, "focal point is center weighted", but try shooting on a tripod using only the center focus point.

    Sam


    That's exactly what I mean. Center focus point is always used, and it doesn't matter if I use a tripod or not. This isn't a camera shake or motion blur issue. I think my camera/lens may have a focus issue.
  • SamSam Registered Users Posts: 7,419 Major grins
    edited May 3, 2011
    That's exactly what I mean. Center focus point is always used, and it doesn't matter if I use a tripod or not. This isn't a camera shake or motion blur issue. I think my camera/lens may have a focus issue.

    OK, I have a Canon 24-105 L f4.0 lens that I have always been dissatisfied with at f4. Two weeks ago I said self, "send the darn thing into Canon, ya got nothing to loose". Well it turns out the auto focus was off. Now it performs well throughout the f range. I could not see any back focus or front focus issue at f4.0, so not sure exactly how / what was adjusted.

    Happy me.clap.gifclap
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