Sony Alpha A6000 – World’s fastest AF – Part 2

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13 Responses

  1. Mic Ty says:

    Good tests. If your objective is to test whether lock-on causes the camera to switch to contrast detection, I propose an experiment: use a subject that moves sideways (perpendicular to camera) and maintains the same distance. If lock-on uses phase detection, then this should be an easy test (because the distance is not changing) where most or all frames are in focus. If it uses contrast detection, then some shots will be in focus, and some will not be. What do you think?

    • Thank you for the suggestion. I am not sure that proposed test will work well because one of the main benefits of PDAF is that it gives 3D coordinates of the subject position. But of course, any controlled test will be good and I will try to do some more, once I receive FE 70-200 f/4 OSS.

  2. Ken says:

    Thanks for these tests, in my opinion you are being kind to this camera. I have been using pro DSLRs for fast action photography of very fast dogs (whippets) for over a decade and the A6000 isn’t good enough to even keep a human walking down the street in focus.

    Ken

  3. Anonymous says:

    Victor,
    I’m not sure why you aren’t using face detection in your testing. It seems that would be useful and provide for a real example AF shooting experience. It’s on by default on the camera and it should have provided more AF assistance in your examples.
    Thanks for all your efforts.
    Pat

    • Hi Pat,

      In my previous post I tried face detection too, but there is also option with registered face detection, that I haven’t tried. Results (with face detection were completely out of focus apart from the first shot (apparently), so there was little reason to post them, but I think I wrote a note about it.
      In general, Sony is using some relatively new “AF features” that have some analogy with traditional features such as shutter priority vs AF priority in the continuous shooting mode, but enhanced with the possibilities of the hybrid AF system. On DSLR, you can usually set (in the Continuous Drive mode and C-AF), if you like camera to fire, giving priority to (pre-selected or maximum) frame per second speed, while ignoring (to certain extent) if the focus is confirmed or not. Or you can set the AF priority, and regardless of the (pre-selected or maximum) frames per second, camera will wait (to certain extent, given by producers algorithm) to confirm the focus, before it fires. There are many reasons why would you like to use first or second option, but it will take me lot of space and time to go through it. To simplify it – imagine that you are shooting acrobat who is jumping across the stage (focus distance remains the same – perpendicular to camera), but you want to be sure that you will have as much as possible shots of the action to select the most exciting moment… In such situation, you will probably choose second option. If you are however somewhere in the curve, waiting for the runners, or bikers to come, and you know that they will run diagonally toward you, you would probably choose first option, because otherwise, most of your shots will be out of focus.
      Sony face detection and probably focus lock-on function works a bit like that DSLRs focus priority setting, where (in theory), they will fire only when the focus is confirmed (on face or on locked-on subject, such as car, motorcycle, bird etc.), reducing thus camera drive speed.
      Therefore, in some situation, you might be more successful with either face detection or focus lock-on, but in others, you will get better results with a plain C-AF and manual tracking.
      When I selected in the above test – focus lock-on, I had results that more or less followed same pattern (with the subject at medium to close distance) 2 shots in focus, two shots back-focused, two shots in focus etc. This behavior is quite typical for CDAF, that can’t estimate distance of the subject from the lens, unlike with PDAF, that should be capable of predicting it. Even the best PDAF systems however (I shot with Canon 1Dx e.g. among others), are fooled sometimes when the subject moves fast toward or from camera, but there is no regularity in those failures unlike the ones I spotted here.
      However, Sony could have used some hybrid AF algorithm for those situations, but that is something new for me and thus I can’t be certain about it.

    • I am pointing that out just to repeat what I already wrote in my post – that I wasn’t disappointed with A6000 AF performance in general. However in most situations in which I would know how to set most DSLRs to get best results within my capabilities, I am quite lost with Sony’s settings. In my comparison with Canon 1D MIII, I didn’t try to compare image quality of both camera/lens combination, but only tracking capability. I don’t mind overall little bit more blurry image from A6000, and as I wrote bellow that comparison, I was actually quite impressed with the results, because focus was mostly well locked across the burst. My settings recommendation – not to use focus lock-on (or face detection) are related to those or similar situations. If I will shot flying birds on the simplified background such as clear sky, flying rather perpendicular to the camera, flaying slower, or staying within reasonable DOF, I might rely on focus lock-on (but still have to see what difference makes two possible settings of that function). If I would shot kids playing in garden and I’d like to have mainly shots of my kid in focus, I would probably use registered face detection, and wouldn’t mind that I’d have 1,2 or 3 f/s instead of 6 or 11.
      AF modes and features are designed in purpose to tell the dumb machine – what we want to keep in focus because they can’t read our minds. In the case of A6000, I would kindly ask Sony to first tell to dumb me – what modes and features should I use, to tell the camera what I want. And writing in their own AF specification description of the AF features (as posted above), in the very first line – “lock-on AF” and two words later “focus lock”, sounds confusing. Oh, I still haven’t get anywhere near “Eye focus” 🙂
      Thanks for looking at my blog.

      regards,
      Viktor

  4. Alin Popescu says:

    Thank you for your time in doing so elaborate tests of focus speed with this camera. When I’ve tested it, I found the AF system a bit tricky, but fast indeed. I also observed the tendency to switch very often to contrast-detect instead of phase detect, which is a pity if you ask me. Actually, the only situation when camera uses phase detect focusing in my opinion is when using AF-C and Wide Area. I have also kept Face Detection to on, as suggested by Pat above, and I got lots of good results. But only with the kit lens, the 16-50 which also raised some questions and not so nice comments from some users :D.
    Now I own the camera, in a final release version (not a sample like the one I’ve tested) and I’ll do more focusing test during my shootings.

    Regards,
    Alin Popescu

    • Thanks a lot Alin, especially for your great early review and for all effort that you put in sharing your findings with us.
      I agree with you – as I wrote at the end of this post – maybe Sony is fastest AF camera today. It is however tricky claim to prove or deny, and it wouldn’t matter at all at the end of the day, if it won’t make some people unhappy, when they find their expectations to be false.
      But again, I can’t and I don’t want to put anyone from buying this great little Sony camera, all I suggested is to read more, think a bit more and consider that they might not get plenty of keepers, without spending some time to learn and try different settings. And related to that, it would be really great if Sony publish a bit more explanatory instructions.
      I am planning to do more controlled tests, asking one or two of my friends – pro sport photographers to try the camera and tell me their opinions, but I am waiting to get FE 70-200 f/4 OSS first and of course to find time to do so.

      Thanks again for looking at my blog, have a great fun with your A6000 and looking forward to see more of yours great images and reviews.

      Best regards,
      Viktor

  5. Anonymous says:

    Hi,
    I read your blog a few days ago and was quite surprised, because I`ve been using A6000 for about 3 weeks now and so far I´ve had no troubles with AF in burst mode. Only lens I have today is 16-50 and since you didn`t test it, I went out to do some tests myself. Camera settings were as follows: burst 11 fps, ISO400, shutter speed 1000 to 1500, fine jpg. I asked my subject to run diagonally towards me and used different AF settings each time (I didn`t test zone and flexible spot area). I just finished to check my results and they were more or less what I expected. Shots taken with wide and center area AF were 100% in focus as long as Lock-on AF was off. With both areas my subject fell out of focus quite soon after she started to run when Lock-on AF setting was on. I olso tested in-camera Action or Sports mode and again – 100% were in focus. Face detection didn`t seem to have impact on my result. Propably it needs some more testing under different circumstances but based on my results I can say that AF in 11fps burst mode works very well with 16-50 kit lens if Lock-on AF is not used.

    Just a little remark: I orederd my A6000 after I finished reading Alin Popescus review 🙂

    BR
    Rait

    • Hi Rait and thanks for your comment. I am glad that it works for you and that is certainly most important. To be able to comment on your findings, I would need to see 100% crops from RAW, unsharpened in pp and to see exact settings, such as FL used, aperture, distance from subject etc. All that can significantly affect results. If the subject was further and if you selected FL at approx. 35mm e.g. and aperture was f/8 or smaller, you might get almost everything at selected distance to infinity in focus, due to the large DOF. That is why. i am waiting for 70-200 f/4 OSS, tontest AF tracking with a pro lens that is supposed to be used for sport and action at a distance. But as I said at the begining, if it works for you, that’s what really matters.

    • Anonymous says:

      I used 50 mm and widest aperture availeable. Subject moved towards me from filling the half of the frame until only upper body fit into frame. It works for me now but I`m certainly not going to stick only with kit lens. My next buy is sony 30 f1,8 so lets see what happens then.

      Rait

  6. priitv8 says:

    Hi Viktor,
    Sorry to chime in so late, but I agree with you that those AF modes take some time to get to grips with.
    AFAIK, the zone-, F-tracking and Face Detection are modes independent of each other and seem to override each other. From my own experience (I have a7) it seems to rank faces highest, tracked objects second and last resort is zone AF. Sony’s own descriptions do not help much. So far best explanation I’ve seen (of any alpha camera), are the e-books by Gary Friedman. In November 2014 he also released an explanatory video on YT:
    https://www.youtube.com/watch?v=306xXWy7Izw
    From all info I gather, Sony needs to hit focus with CDAF first, and uses PDAF only in AF-C mode to track the subject. My own small test with a7II and FE 70-200 G show similar results – the camera occasionally loses focus, but then recovers:
    https://www.flickr.com/photos/priitv8/15854896523/in/set-72157650156249089

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