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Sony Flashes w/ AF Assist

Discussion in 'Photography & Video' started by quwackers, Oct 29, 2018.

  1. quwackers

    quwackers Member

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    Hey everyone, as an event photographer I have been using my A7III for just under 6 months now and have found that the AF Assist light on the Camera is less than ideal.

    This solution is often slower and can entirely miss focus in uncontrollable environments (fog machines at event).

    I have however found out that the Godox XproS provides support for its Auto Focus Assist Beam which when I tested appears to work fantastically, in fact it performed much better than the Sony assist light.

    What I want is to compile a list of hot shoe compatible devices which support this feature.

    I figure this may help someone else when purchasing a flash for their camera :)

    Supported:
    • Godox XproS

    Unsupported:

    • Godox TT685S
     
  2. Deftone2k

    Deftone2k In the Darkroom

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    Have you used the Sony flashes themselves? I havent tested with, but by all reports most users dont have a problem shooting low light with the Sony's anyway.

    Are you using adapted glass?

    Being that the Sony doesnt use AF assist (being mirrorless) like a traditional DSLR setup.. its just a LED light that provides a bit of light for contrast for detection.
     
  3. OP
    OP
    quwackers

    quwackers Member

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    I have not used the Sony flashes, that is a good point I might try to find some in a store. But I do believe that if they only leverage a assist light similar to what is on the body it would be no significant improvement in any challenging environment.

    In low light situations the on body light is fine, but extreme low light it fails (as I tested with a ND filter in a dark room, the flash assist could still focus, the assist light could not), and once again I imagine if smoke or haze was involved it would also fail.

    I use only native glass, I don't have anything adapted, specifically the Sony 16-35mm F4 for the aforementioned tests.

    My understanding is that (at least for gen 3 A7's) the Sony's use a hybrid system using both phase and contrast detection, it is known phase detection is superior in low light.

    I noticed a significant difference in my tests between the XproS AF Assist and the on camera light, I am talking complete inability to focus in the situation vs perfect focus with the AF Assist, it's clear (to me at least) that Sony cameras must be able to harness the Flash AF Assist in some capacity.

    Edit: The first response to this thread was what set me on this path and prompted my own investigation (https://www.dpreview.com/forums/thread/4266745#forum-post-60926063).
     
    Last edited: Oct 29, 2018
  4. Xang

    Xang Member

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    I've been shooting the XProS for a few months and I never noticed it even has an AF-assist light. How do you enable it?
     
  5. lonewolf1983

    lonewolf1983 Member

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    DPreview are on the money with their article - they are discussing on camera flash AF assist though (rather than just using the controller for the camera only AF assist)

    it would be a pain if you're using on camera flash but need to have the wireless controller in between just to get AF assist...

    The Sony flashes basically use a bright white LED for af-assist, its pretty obnoxious vs the grid pattern AF systems
    I gave up on using mirrorless for my on-camera flash stuff, and used them for ambient lighting candids instead.
     
  6. FranchiseJuan

    FranchiseJuan Member

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    I am not sure if you all know, but the infra-red af assist beam that flashes let out does not really help with low light AF with mirror-less cameras.
     
  7. Xang

    Xang Member

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    Mirrorless AF points cannot detect IR at all, so the IR beams make zero influence.
     
  8. lonewolf1983

    lonewolf1983 Member

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    the visible spectrum may - but then reading the DPreview stuff indicates that maybe the red/green colours dont actually become visible to the sensor.
    So you're stuck with white light or nothing
     
  9. OP
    OP
    quwackers

    quwackers Member

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    You'll have to update its firmware (http://www.godox.com/EN/Download.html).

    It may not be the IR affecting it, but I definitely think the pattern and better positioning of the beam make a huge difference.
     
  10. TheBear21

    TheBear21 Member

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    If you shoot with constant focus (and who doesn't?) then you will never get AF assist lights.

    And as stated all bar the current Sony speed lights use an IR light that can't be seen by your sensor. The next generation of Godox light will use a regular LED, but that brings us back to who doesn't use AF-C on Sony? That is the main reason people use it, is for the face/eye auto focus.
     
    quwackers likes this.

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