Thanks for visiting us!

Badminton Central is a free community for fans of badminton! If you find anything useful here please consider registering to see more content and get involved with our great community users, it takes less than 15 seconds! Everybody is welcome here.

Click here for a FREE account!

Any tips on focusing?

Discussion in 'Badminton Photography' started by Sealman, Jun 17, 2008.

  1. Sealman

    Sealman Regular Member

    Joined:
    Nov 11, 2004
    Messages:
    4,236
    Likes Received:
    16
    Occupation:
    Racquet Collector
    Location:
    Singapore
    When I am shooting behind the court, I find that the net always gets in the way. The lens would focus on the net (the nearer object) rather than the players on the opposite side. Believe I am focusing incorrectly. Do you guys encounter the same problem as I do? Where should I aim then?
     

    Attached Files:

  2. Cheung

    Cheung Moderator

    Joined:
    Apr 25, 2002
    Messages:
    16,238
    Likes Received:
    31
    Occupation:
    wannabe badminton phototaker
    Location:
    Outside the box
    Is this the full photo or cropped?

    What AF mode?

    What focussing point do you use?
     
  3. kwun

    kwun Administrator

    Joined:
    Apr 24, 2002
    Messages:
    39,263
    Likes Received:
    528
    Occupation:
    BC Janitor
    Location:
    Santa Clara, CA, USA
    the camera naturally look for contrasty objects to focus on. on the image example above, if your focus point is on the yellow shirt, going through the net, the camera will try to focus on the net because it has more contrast compared to the shirt.

    the solution is to put the focus point on part of the player which has more contrast, the face is a good candidate, or the border between the yellow shirt and the black short.

    however, camera AF are not perfect, sometimes they do miss focus.
     
  4. ctjcad

    ctjcad Regular Member

    Joined:
    Sep 27, 2004
    Messages:
    19,144
    Likes Received:
    4
    Location:
    u.s.a.
    Just want to add..

    ...in the Canon 40D, the camera i assume you were using, there are a few options for the AF. If i remember correctly, there are 3 types of AF mode; the ONE SHOT, AI FOCUS and AI SERVO. What you want to try to use, esp. for baddy pics, is either the AI FOCUS or the AI SERVO mode, esp. when shooting through the net. Basically, with the AI SERVO mode you'll be able to focus on your moving subjects and the subjects will be focused continuously, while you hold down the shutter button (halfway). With the AI FOCUS mode, the AF switches from the One Shot AF to AI SERVO AF.
    *More info should be in the manual.
    Of course, as mentioned by kwun, you want to pick the an area with more contrast, initially.:cool:
     
  5. Sealman

    Sealman Regular Member

    Joined:
    Nov 11, 2004
    Messages:
    4,236
    Likes Received:
    16
    Occupation:
    Racquet Collector
    Location:
    Singapore
    Its a cropped photo and the AF mode is One Shot. I believe I aimed at Nasir's face.
     
  6. Sealman

    Sealman Regular Member

    Joined:
    Nov 11, 2004
    Messages:
    4,236
    Likes Received:
    16
    Occupation:
    Racquet Collector
    Location:
    Singapore
    guys, many thanks for the advice!
     
  7. Cheung

    Cheung Moderator

    Joined:
    Apr 25, 2002
    Messages:
    16,238
    Likes Received:
    31
    Occupation:
    wannabe badminton phototaker
    Location:
    Outside the box
    Can you show the uncropped photo?

    How many AF points is your camera set to?

    We can give a full diagnosis once we got that explanation.:)
     
  8. ctjcad

    ctjcad Regular Member

    Joined:
    Sep 27, 2004
    Messages:
    19,144
    Likes Received:
    4
    Location:
    u.s.a.
    ^^Just like an MD...^^

    ...full diagnosis once everything is laid out...:cool:
     
  9. kwun

    kwun Administrator

    Joined:
    Apr 24, 2002
    Messages:
    39,263
    Likes Received:
    528
    Occupation:
    BC Janitor
    Location:
    Santa Clara, CA, USA
    2 points.

    - the actual size of the focus sensor is larger than the little red box shown on the viewfinder. so give it a bit more space.

    - i noticed a few of your photos have mis-focused. i don't know if that is operating error or maybe the sensor/lens needs to be calibrated. i suggest doing a static focus test to check it out. i usually use a tripod, and then focus on flat paper with a pattern on it. everything should come out tack sharp if the focus is accurate.
     
  10. Cheung

    Cheung Moderator

    Joined:
    Apr 25, 2002
    Messages:
    16,238
    Likes Received:
    31
    Occupation:
    wannabe badminton phototaker
    Location:
    Outside the box
    I also noticed quite a few of Sealman's photos off focus. Once we get the uncropped photo, we can be pretty sure of the problem.

    Forgot to ask, what lens was used for this shot?
     
  11. kwun

    kwun Administrator

    Joined:
    Apr 24, 2002
    Messages:
    39,263
    Likes Received:
    528
    Occupation:
    BC Janitor
    Location:
    Santa Clara, CA, USA
    70-200/2.8IS:

    [​IMG]

    did you have IS turned on? were you panning a lot when you took the photo?
     
  12. Sealman

    Sealman Regular Member

    Joined:
    Nov 11, 2004
    Messages:
    4,236
    Likes Received:
    16
    Occupation:
    Racquet Collector
    Location:
    Singapore
    yeah IS was turned on... no panning

    ps. hmm isnt that uncle loh's photo?
     
    #12 Sealman, Jun 19, 2008
    Last edited: Jun 19, 2008
  13. Sealman

    Sealman Regular Member

    Joined:
    Nov 11, 2004
    Messages:
    4,236
    Likes Received:
    16
    Occupation:
    Racquet Collector
    Location:
    Singapore
    I attach below two uncropped photos for your diagnosis:
     

    Attached Files:

  14. Cheung

    Cheung Moderator

    Joined:
    Apr 25, 2002
    Messages:
    16,238
    Likes Received:
    31
    Occupation:
    wannabe badminton phototaker
    Location:
    Outside the box
    Thansk for the photos.

    Three possibilities:

    1) You have the AF on 9 points. If so, it will focus on anywhere that an AF point can go. The highest contrast is the net so for these two pictures, you got the net. Solved by picking a single AF point.

    2) If you have the AF on centre single point, the AF point has overlapped with the net and the AF focuses on the top of the net (that's the highest contrast point). When you look through the camera viewfinder, the AF red dot area is actually larger. Solve by zooming closer - the top of the net will not be so close to the person's face in the viewfinder.

    3) If you are one shot mode, the camera picks up focus on thet net, then you move reframe the shot because teh subject has moved. But, the AF is already locked on the net. Solved by using AF-servo.

    For both your pictures, the key person in the image is a bit small and low contrast so the AF has picked on the net.
     
  15. Cheung

    Cheung Moderator

    Joined:
    Apr 25, 2002
    Messages:
    16,238
    Likes Received:
    31
    Occupation:
    wannabe badminton phototaker
    Location:
    Outside the box
    [​IMG]

    For the above image, I did very little cropping. I use AF servo with centre point focus. Of course I want Tony's eyes in focus but you can see the top of the net is very close to his face. What I did was aim the centre AF point towards the highest contrast point which is approximately vertically below his face. i.e. I aimed at the line of the white shirt and black shorts.
     
    #15 Cheung, Jun 19, 2008
    Last edited: Jun 19, 2008
  16. Sealman

    Sealman Regular Member

    Joined:
    Nov 11, 2004
    Messages:
    4,236
    Likes Received:
    16
    Occupation:
    Racquet Collector
    Location:
    Singapore
    Cheung, many thanks for your advice.
     

Share This Page