GX85 Focusing question please

Discussion in 'Panasonic Cameras' started by Frankgr, Sep 20, 2016.

  1. Frankgr

    Frankgr Mu-43 Regular

    Oct 18, 2014
    If this has been dealt with before please provide a link.

    I need clarity around setting & using Focus Mode >AFF (auto focus flexible) in the menu, and Auto Focus Mode>Tracking on the button.

    Do I use them separately and/or in conjunction with one another.

    If I understand it correctly, the 'AFF' adjusts the focus if the target moves nearer to or further away from camera.
    The 'Tracking' tries to move the focus point to find the subject if it moves laterally off the original point.

    Is AFF fast enough to reset focus while the subject moves nearer/faster vs lifting your finger pressure and pressing half way again in AFS?
    And is Tracking quick enough to re-find or keep up with, a laterally moving target vs re-framing with 1-area / single point?

    I am either shooting young children who are occasionally still while playing but mostly unpredictable movements. Or,
    I'm doing 'street photography' and trying to frame and shoot quickly in an environment that is constantly flowing, including me.

    Any links or advice on best focus settings to use please
  2. MoonMind

    MoonMind Mu-43 Top Veteran

    Oct 25, 2014
    Real Name:
    I'm a bit surprised noone answered this one sooner; probably a bit too specific, but if you can live with me starting from a more general point, I think I can help out.

    First observation: AF-S (single point) on the GX80/85 is insanely quick. If you've got the camera up at your eye and are following your subjects anyway, you'll be able to get an AF fix and fire in a split second - I have found this to give me the images of moving people I was after so far, and that's the case even with the smallest AF point size - though *not* Spot AF, but that's for highest precision only in special circumstances anyway (like macro), certainly not for movement. So, in a nutshell, S-AF to actually catch subjects works fine if you know what you're doing. If you prefer to use back-button AF, that's another way of doing it - I stick to using the shutter button.

    Second observation: I tried tracking with the GX80 - it's not bad, but certainly not as satisfying as on a good DSLR; it's far from smooth, especially if the movement exceeds a certain speed, and it's not fast enough to catch sudden movements at all in my opinion. It's reasonably good at regaining focus, but it'll rack back and forth, sometimes quite wildly. I'm put off by this because I feel as if I didn't have enough control over what happens - and since it's not as fast and accurate as AF-S, I really don't see the point when doing documentary or street. It'd be a big help in a controlled situation, though, coupled with face detection - you can interact with your subject while the camera does the job of keeping focus. But that's about it from my point of view - the GX80/85 doesn't track well enough for sport or action in my personal experience.

    Anyway, generally I'd advise against using AF-F - it means the camera decides when to move or to keep the AF fix, and this in turn means that you have to put up with whatever it does. If you decide to use tracking, use AF-C, preferably single-point, maybe changing the size of the AF point to mediom. It works reasonably well this way.

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