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G9 + 100-400mm lens: Autofocus Locks on Background

Discussion in 'Panasonic Cameras' started by Ajay1, May 23, 2019.

  1. Ajay1

    Ajay1 Mu-43 Rookie

    19
    Feb 28, 2014
    SE MN
    I've had the combination of the G9 and 100-400 lens for over a year now. Currently at the latest firmware update as far as I know (v 1.2). I still run into a problem when photographing birds at close range...If the G9 grabs focus on the background, it is nearly impossible to refocus on the foreground bird. The only thing I can do at this point is point the camera at another nearby object that nearly fills up the framed image, then it will refocus on the foreground and I can then focus on the foreground bird -- if it's still there.

    I have tried every focus point setting known to this camera. I have tried every autofocus setting known to man. No matter what setting, if you lose close focus and it grabs the background, good luck in re-establishing foreground focus on subjects that fill up about 40% of the frame or less.

    The strange thing is, is that the G9 appears to recognize that a foreground object exists, but never switches focus. I use back button focus and keep pumping it, hoping it will grab the foreground subject.

    It's always been a frustration with this camera and the 100-400mm lens. (I wish the lens had a close focus switch so that it would prevent the lens from trying to focus to infinity.)

    I'm curious to know if others have this same problem and if there is any setting I am missing (although I think I have tried everything).

    Because of this problem I primarily use this camera and lens for wildlife video work only.
     
    • Agree Agree x 1
  2. Brownie

    Brownie Mu-43 Top Veteran

    795
    Sep 3, 2018
    SE Michigan
    Poke around here in the Panasonic forum and look for the birding threads. Tons of discussion on background focusing, etc. There are some guys on here that are very successful with the G9 in the same circumstances.
     
  3. Brownie

    Brownie Mu-43 Top Veteran

    795
    Sep 3, 2018
    SE Michigan
  4. Ajay1

    Ajay1 Mu-43 Rookie

    19
    Feb 28, 2014
    SE MN
    I'm not talking about BIF settings. I am talking about initial focus of close subjects. They do not need to be in-flight.

    For example, a bird perched on a thin, metal fence post 30' away. Behind the fence post, there is a tree line. The camera is focused on the trees. Attempting to refocus on the bird or the thin metal fence post in the foreground is a lesson in futility. The only way to get close focus is to focus on the base of the fence post in which the ground fills the frame, then pan up and hopefully the bird is still there.

    BTW, the focal planes of the bird in foreground and trees in background are very far apart. In other words, when the bird is in focus, the background is completely blurred with no definition.

    Here's an example:
    _1472292_small.jpg
    Subscribe to see EXIF info for this image (if available)
     
    Last edited: May 23, 2019
  5. Pluttis

    Pluttis Mu-43 Veteran

    458
    Nov 14, 2016
    Sweden
    Peter
    I dont own a Pansonic camera, but cant you set it up with AF+MF so MF overrides AF-S/AF-C? , if possible it would let you quickly adjust focus manually while you still hold the shutter half pressed.
     
  6. Jrsforums

    Jrsforums New to Mu-43

    5
    Mar 13, 2019
    Have you tried ‘one area’, with the box reduced to mostly just include the bird?
     
    • Agree Agree x 1
  7. I had a similar problem with this lens and the olly 5 mk ll. Many times it just refused to focus and simply hunted, mainly in low light with low contrast. I get the best out of it by locking the small square permanently in centre and focusing, for example in your pic above, with the square overlapping the highest contrast area of the subject such as the dark wing and the pale chest, if the eye and head colour doesn't work. I then recompose with shutter half pressed. The forgiving nature of m43 DOF seems to help with the move of POF
     
    • Agree Agree x 1
    • Informative Informative x 1
  8. D7k1

    D7k1 Mu-43 Hall of Famer Subscribing Member

    Nov 18, 2013
    I have seen that behavior and I use either manual focus or switching focusing distance switch on lens, takes less than a second and you don't move off target. Doesn't happen that often on mine. Also happens on my Gx8, and I do the same thing to fix it.
     
  9. Ajay1

    Ajay1 Mu-43 Rookie

    19
    Feb 28, 2014
    SE MN
    Yes. I actually reduced the size of the one focus point as small as I could make it and it had no effect. Even though the one, small focal point clearly was only on the bird, it would never focus on the foreground bird. Good idea and one that I thought would work.
     
  10. Ajay1

    Ajay1 Mu-43 Rookie

    19
    Feb 28, 2014
    SE MN
    I tried MF + AF as well as AF-S and it make no difference. It still cannot pick out the foreground subject. Thanks.
     
  11. Ajay1

    Ajay1 Mu-43 Rookie

    19
    Feb 28, 2014
    SE MN
    Thanks. Using manual focus is a work-around of sorts and does work as long as I have time to get it close to the foreground bird before it takes off. Still a bit time consuming however. Once the lens has gained near-focus, it does lock-on and hold focus. It's the initial focus that is the problem.
     
  12. Pluttis

    Pluttis Mu-43 Veteran

    458
    Nov 14, 2016
    Sweden
    Peter
    This is what i meant when i said "AF+MF so MF overrides AF-S/AF-C , if possible it would let you quickly adjust focus manually while you still hold the shutter half pressed"
     
  13. masayoshi

    masayoshi Mu-43 Top Veteran Subscribing Member

    853
    Dec 5, 2016
    Salt Lake City
    Masaaki
    AF+MF adjustment works when the initial lock is close. But in OP's case, where AF lock goes to background (infinity), it takes very long turn of the focus ring before getting close to the target. I think what's going on here is due to the distance between the target and the background. If the distance is to long, DFD may take very long time to find out good contrast in the target area/box.

    As a remedy, does G9 have Preset MF override, so that it resets the FL to something like 10-20m, and restart AF from there? I used to own G9 but sold recently, and can't remember.
     
  14. Pluttis

    Pluttis Mu-43 Veteran

    458
    Nov 14, 2016
    Sweden
    Peter
    Thats true, it will require long turn/time but i think its either that or with AF refocus on the foreground and then pan up and focus on the bird
     
  15. Stanga

    Stanga Mu-43 Top Veteran

    902
    Oct 16, 2016
    This focusing issue is not limited to the 100-400mm. It's possible on other lenses as well. I get it on the 14-140mm MKII, but less so on the 45-175mm.
     
  16. Pluttis

    Pluttis Mu-43 Veteran

    458
    Nov 14, 2016
    Sweden
    Peter
  17. Ajay1

    Ajay1 Mu-43 Rookie

    19
    Feb 28, 2014
    SE MN
    I just saw something here that leads me to believe this is a contrast-detect problem and has nothing to do with the 100-400mm lens nor the G9. I was watching a video from Kai W reviewing the Panasonic S1. In his video at the 6:24 mark, he describes almost the exact same problem using the S1. Just as I have seen, the camera seems to recognize there is a foreground subject, but stays stuck on a busy background. It now has me wondering if this is a limitation of contrast-detect autofocus? Or they need to fix their firmware? Even on the S1.

    Here is the video. Go to the 6:23 mark.


    FYI, I am not trying to pick on Panasonic. I love their cameras but this problem does have me frustrated. Thanks to everyone for their feedback.
     
  18. kinlau

    kinlau Mu-43 Top Veteran

    948
    Feb 29, 2012
    I also have the same problem with the G9 and 100-400, and my workaround is to just do a quick point at the ground and shoot, and then acquire my target.

    Something that occasionally works, especially if I can’t shoot the ground (eg snow covered ground is just as bad), is to flick the AF joystick and the double pump or long press (1 sec or more) the shutter. That seems at times to cause the AF to try harder.
     
    • Like Like x 1
  19. D7k1

    D7k1 Mu-43 Hall of Famer Subscribing Member

    Nov 18, 2013
    Think it is just something we have to live with, but I do agree it can be frustrating at times. Since I shoot mostly BIF against sky or water not a deal breaker for me.
     
    • Like Like x 1
  20. Phocal

    Phocal Mu-43 Legend Subscribing Member

    Jan 3, 2014
    Houston
    How much crop is on this photo?
     
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