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20mm pancake AFS
  • LongJohnSilverLongJohnSilver
    Hi Vitaliy,
    The lumix lenses, when used in video mode, set automagically in AFC regardless if AFC/AFS is set on the camera. AFC is useless on all the lens except (maybe) on 14-140mm. I know that MF is the best option but for underwater use some housing doesn't have the focus ring so the half pressing the shutter button to trig the focus is the only way to get a decent autofocus.

    Is this behavior (forced AFC) something triggered by the camera firmware or the lens firmware?

    Thank you in advance
  • 24 Replies sorted by
  • Vitaliy_KiselevVitaliy_Kiselev
    I don't have any idea. Never looked at this.
  • LongJohnSilverLongJohnSilver
    According to Panasonic GH1 user manual all the lumix lenses should behave in this stupid manner in video mode.
    Weeks ago posted this on dvxuser and other users where experiencing different behavior.

    On my 14-45 the AFS works also in video mode
    On my 20mm pancake AFS doesn't works.

    For this reason I did not buy the 7-14mm because with the uw housing I would be forced to AFC.

    Thanks
  • fehafeha
    I wish this could be hacked, as in photo mode the AF is very fast ...
    (in video mode they have reduced the motor speed in order to avoid noise that can be picked up by mic)
  • v10tdiv10tdi
    FWIW - here is a Panasonic resource (English) that "officially" lists lens compatibility (including focus behavior) for GH2:
    http://panasonic.jp/support/global/cs/dsc/connect/gh2.html
  • LongJohnSilverLongJohnSilver
    Actually that complicated table doesn't tell that AFS is not available in video mode (14-45mm and 20mm).
    They think that AFC is a good thing in video mode.
    In my 14-45mm I half press the shutter button and then the camera focus. After that the focus stay blocked. I wish the same behavior on the pancake! :)
  • v10tdiv10tdi
    @LongJohnSilver
    Yes, the table is confusing. So is the manual - especially if you add AFL and AEL to the mix.

    You can achieve one-time AFS while shooting video w/20mm. I think this is what is meant by "Shutter Button*=One shot AF operation in response to the Shutter button halfway pressing" in the table. Better than nothing, but not as good as...on-demand AFS on the 14-140mm.


  • v10tdiv10tdi
    Well - I thought I understood it.

    After some experimenting, my 20mm seems to exhibit AFS focus behavior same as 14-140mm. Specifically, with Movie Continuous AF set to "Off" the 20mm lens will hold focus while recording movie until I press the shutter button halfway. It will then re-focus, albeit slower than with the 14-140mm.

    Is this the movie AFS focus behavior you were looking for?
  • LongJohnSilverLongJohnSilver
    @v10tdi
    Yes!!!
    How did you get it? On my GH1 with the 14-45mm I just rotate the small wheel to AFS, AFC, MF and the camera behave accordingly. With the 20mm I have only AFC and MF.
    I lost some menu...
  • RamboRambo
    @v10tdi ... Is this the movie AFS focus behavior you were looking for?

    Can't get that to happen on my 20mm, what menu settings are you using?

    My 45 - 200 Pana will snap focus during recording but not the 20mm
  • stoneystoney
    In GH1, AFS acted like AFC. Three ways to lock the focus.

    - AFS to MF
    - Use focus and exposure lock. Enable lock hold option.
    - Hold shutter button.

    In GH2, there is an option to turn off continuous autofocus. Then AFS does only one-time focus. Half-pressing shutter will do autofocus again.
  • v10tdiv10tdi
    @Rambo
    "Can't get that to happen on my 20mm, what menu settings are you using?"

    Movie Continuous AF = Off
    I also have AF/AE Lock set to AF, only - but I'm not sure it's needed for this.

    Just remember that the AF on the 20mm is much slower than 14-140mm.

    I tried experimenting with AF Lock, mostly as described by @stonebat, but I didn't pursue it much because I was able to achieve what I needed just using the shutter button. The Panasonic web page/manual is confusing...seems like writer is not native English speaker/writer/reader. ;-)

    I can work on it with you more tomorrow (via PM?) if you can't observe same behavior.
  • RamboRambo
    l'm with the original poster, as we both are using GH1 and we don't the extra menu function (cont AF off) in this camera.
  • stoneystoney
    http://www.personal-view.com/talks/discussion/378/time-lapse-controller-for-gh1-and-gh2/p1 TC-252 has bulb mode that locks the AF on GH1.
  • LongJohnSilverLongJohnSilver
    @v10tdi
    Me and Rambo are speaking about GH1 and we do not have this function. Are you usung the GH2?

    @stonebat
    Nice to that that time lapse controller does the trick. I'll try holding the shutter button.

    Anyway if it something related to the GH1 camera, would be nice investigating if can be hacked. The AFC is very annoying.

    @Vitaliy_Kiselev
    If the GH2 has this function, could be possible to see where the camera store and read this information and checking if the GH1 could have the same function as patch?

    Thank you all guys
  • v10tdiv10tdi
    Yes, GH2. Sorry I didn't make that more clear in my original post.
    Here is the link for the GH1 compatibility table:
    http://panasonic.jp/support/global/cs/dsc/connect/g1.html

    I did a quick comparison for the Panny m43 lenses and the tables look the same.

    I don't have a GH1 to test. But can you get a "single" focus lock that you can engage prior to shooting, then unlock during shooting (for continuous focus). Not as flexible, probably can't access AE/AF Lock button in an UW case...
  • LongJohnSilverLongJohnSilver
    @v10tdi

    Uh!?!
    You wrote: "After some experimenting, my 20mm seems to exhibit AFS focus behavior same as 14-140mm..."

    Do you have a GH2? How do you engage the AF prior to shooting? With AF Lock?

    Bye
  • v10tdiv10tdi
    Sorry again that I wasn't clear. I have a GH2.

    Yes, I can engage AF prior to shooting with the AF lock. This is useful function.
  • RamboRambo
    A half shutter press snaps the focus and use your thumb to lock it by pressing AF/AE lock button. (GH1)
  • LongJohnSilverLongJohnSilver
    Thanks guys I'll give a try
  • fehafeha
    How about when shooting in movie mode , GH2 ?
  • v10tdiv10tdi
    @feha
    >How about when shooting in movie mode , GH2 ?

    Yes, AFS works in movie mode with the GH2+20mm.
  • fehafeha
    Hmm,
    i have to test, i'm not able to do it while shooting ...
    (before press "record" works but ...)
  • v10tdiv10tdi
    @feha

    Remember 20mm is much slower to focus than 14-140mm. PM me with any questions.
  • pedrinhopedrinho

    Ok I had an issue with this but I'm sorted now therfor I'll share my experience.

    To achieve proper AFS behavior while recording motion you need to first: -set "CONTINUUS AF" to OFF in Motion Picture menu -make sure that in Custom menu SHUTTER AF is ON.

    That's it. Start recording. Now camera will AF only when you PRESS&HOLD shutter half way. Remember that 20mm pancake is quite slow focus lens and it sometimes gives impression that it dosen't seems to do anything. Another thing is that aparently during video AF happens much slower then when doing stills.

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