No PDAF for u43 lenses on E-M1

Discussion in 'Olympus Cameras' started by pdk42, Sep 10, 2013.

  1. pdk42

    pdk42 One of the "Eh?" team

    Jan 11, 2013
    Leamington Spa, UK
    From the Pocket-Lint review:

    "Pop a newer Micro Four Thirds lens on the front and the phase-detection system is ignored"

    I suspected as much. No BIF, sports or such like then - pity!
  2. Bizzarrini

    Bizzarrini Mu-43 Regular

    Apr 26, 2011
    The Netherlands
    Only in SAF from what I read, it uses PDAF in CAF mode
  3. Promit

    Promit Mu-43 All-Pro

    Jun 6, 2011
    Baltimore, MD
    Promit Roy
    This is what most of the reviews are saying. Seems like a reasonable decision to me.
  4. pdk42

    pdk42 One of the "Eh?" team

    Jan 11, 2013
    Leamington Spa, UK
    I hope this is true. It's a massive missed opportunity / oversold expectation if PDAF is only going to work on the legacy 4/3 lenses.
  5. jomerads

    jomerads Mu-43 Veteran

    Mar 27, 2013
    Moorestown, New Jersey
    John S.
    Isn't it that you only need it in CAF anyway for micro4/3's lenses and full time for legacy 4/3's lenses? Ming Thein did say that it worked in CAF.

    What about Iso 100 and focus peaking? Absent in EM1? but present in EP5.

    John S.
  6. kevinparis

    kevinparis Cantankerous Scotsman Subscribing Member

    Feb 12, 2010
    Gent, Belgium
    how can it be an 'oversold expectation' when until today, Olympus hadn't actually said anything that would raise expectations

    from my limited understanding, the way a lens designed for PDAF works and the way the one designed for CDAF works are very different in terms of how the motors that do the focussing work have to function. Indeed there are stories around of people burning out motors on PDAF designed lenses fro the 4/3 system while trying to use them on CDAF bodies.

    suggest you read this blog

    pekkapotka - Journal - Olympus OM-D E-M1: Autofocus

    and his overall review of the m1

    pekkapotka - Journal - Olympus OM-D E-M1 hands on preview

  7. gotak

    gotak Mu-43 Regular

    Nov 28, 2012
    Check the dpreview feature list. PDAF for c-af on u43 lenses.

    That isn't the real question. For me is how good is PDAF with u43 lenses if it's crap it's going to be almost like they didn't put in PDAF for those of us with only u43 lenses.
  8. kevinparis

    kevinparis Cantankerous Scotsman Subscribing Member

    Feb 12, 2010
    Gent, Belgium
    do your research.. I can't quote chapter and verse, but in all I have read about the em1 today, I have seen mention of ISO 100 ( though not native) and focus peaking, though the guy who did mention it seemed to think it didn't work with manual lenses... which does seem odd

    guys... its day one of actual information... not rumours

    Olympus have way way more experience of designing and building cameras than anyone here or elsewhere on the internet... any decisions/compromises they have made will be for very good reasons. This is their flagship camera... they will have done the very best they can do for the market they are trying to address. If that market is not you... then buy some other camera.

    Personally I am disappointed on the video aspect of the camera... but I understand that Olympus have no presence in that field, unlike panasonic who have a whole pro video division to help them out and generate future opportunities for

    You have to remember, camera manufacturers dont primarily make cameras to take photographs, but to make a profit. They make decisions and compromises to maximise their profit.

    And sometimes thing that seem easy and insignificant to us the user can have big ramifications to the company.

    I remember years ago watching a documentary about airline food. There was a discussion about whether to put one chocolate or two on your infllght meal.... that was literally a million dollar a year question!!!

  9. pdk42

    pdk42 One of the "Eh?" team

    Jan 11, 2013
    Leamington Spa, UK
    Well, the frenzied chat on about every forum over the last month has been talking about hybrid/PDAF on the new E-M1. Every leak and piece of gossip has been mentioning PDAF. Above all features on the new model, I think it's this that has generated most interest. We all want C-AF that works!!

    Exactly. I thought as much too, but there are many who thought that Oly could pull off some magic and give us PDAF and C-AF tracking that works on our u43 lenses. I still really hope there is some improvement in this respect.

    Thanks - will do!
  10. demiro

    demiro Mu-43 Hall of Famer

    Nov 7, 2010
    This is one take-away from the DPR preview that caught my eye:

    I'm reading that to mean that the E-M1 will still lag behind a decent DSLR in terms of tracking action. But it's early, obviously, with more tests to come.
  11. Mix

    Mix Mu-43 Top Veteran

    Jul 8, 2013
    This video says that there's focus peaking, it's the button near or close to the grip and lens.

    [ame=]Olympus OMD EM-1 Review - Hardware - YouTube[/ame]
  12. STR

    STR Mu-43 Veteran

    May 16, 2013
    IN CDAF: the lens moves a slight amount, stops, measures the sharpness of the selected focus point, and moves again, stops, measures the sharpness and then compares it to the previous measurement. If it's less sharp than the first time, it will move back to the previous point and report focus lock. If it's sharper, the cycle begins again until the contrast maxes out. This move/stop/measure cycle happens up to 240 times a second on newer Panasonic cameras and lenses and 120 times on all other MFT products.

    In order to facilitate this rapid movement, special motors that won't burn out in this kind of use are used. Additionally, lenses are specifically designed with smaller focusing elements which take less power to move.

    PDAF works on the fact that most light entering a pixel has been refracted by at least two spots on the lens. If out of focus, the lens will duplicate those two entry points. The camera detects the offset and calculates how far the lens has to move for the light to focus on one point. The lens is moved into position in one motion and the camera reports focus lock.

    Because there's no rapid start/stop motion, there's a lot fewer restrictions on how you build and power the lens. You can use a more powerful motor to move larger focus elements which would overheat or tear itself apart when used in CDAF. However, there is no fundamental reason why a lens designed for CDAF can't also be used for PDAF. CDAF lenses can do both. In fact, I believe there's a couple of 4/3 lenses which were sold as being cross compatible.

    Which makes this restriction really odd. Are they trying to upsell us to the new PRO lenses? Because that would be horse ####.
  13. FastCorner

    FastCorner Mu-43 Veteran

    May 28, 2011
    Anyone know if the focus point can be changed while looking through the EVF? Preferably, with the touch screen.
  14. Djarum

    Djarum Super Moderator Subscribing Member

    Dec 15, 2009
    Huntsville, AL, USA
    OT, for a second, but I can see why PDAF motors would burn out. However, I don't see how CDAF motors would burn out using a PDAF system. CDAF have to keep adjusting and checking where PDAF systems tell the motor exactly where to put the focussing lens group. What could be a problem is if information, or, some value about the location of the focus gets reported back to the the camera, which could be important in a PDAF system. They may have ommitted this from a CDAF lens, like mFT, which could make it slightly more difficult. But that could be a firmware upgrade on the lens.

    Back on topic, it does appear that CDAF works ok for mFT lenses. It appears to be a step in the right direction.
  15. kevinparis

    kevinparis Cantankerous Scotsman Subscribing Member

    Feb 12, 2010
    Gent, Belgium
    just speculating... but maybe olympus have found that CDAF can be made to work faster than PDAF for single autofocus due to faster processors, better motors, lighter lens elements.. Maybe CDAF offers a better path going forward for even faster AF...maybe a combination of PDAF and CDAF is a magic bullet for better tracking AF who knows?... I would bet Olympus have a much better grasp on the problem and its solutions than endless laptop experts who turn ill understood features and capabilities into bizarre conspiracy theories.

  16. Djarum

    Djarum Super Moderator Subscribing Member

    Dec 15, 2009
    Huntsville, AL, USA

    Then what fun would it be :tongue:
  17. kevinparis

    kevinparis Cantankerous Scotsman Subscribing Member

    Feb 12, 2010
    Gent, Belgium

    aye... there is that aspect....but we all get our fun from different places


  18. entropicremnants

    entropicremnants Mu-43 All-Pro

    Jul 16, 2012
    John Griggs
    The chief advantage for PDAF on S-AF mode would be slightly quicker acquisition of focus but only because the camera knows which way to start turning the motor.

    But modern CDAF is so fast (especially Olympus) it's not MUCH of an advantage so if it does only work in C-AF or "tracking" that's what it really needs to be there for. I don't see this as a major deal myself.
  19. pdk42

    pdk42 One of the "Eh?" team

    Jan 11, 2013
    Leamington Spa, UK
    Having now read the Pekka Potka article, I'm now feeling more optimistic about the new AF performance. It seems that with both FT and MFT lenses, he managed a reasonable degree of C-AF accuracy. This is really good news. Will be good to hear what other reviewers say as the camera starts to get around.
  20. jnewell

    jnewell Mu-43 All-Pro

    Jun 23, 2011
    Boston, MA
    Maybe when the frenzied chat starts designing and bringing cameras to market we'll stop having this tantrums of bitterness??? :biggrin:
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