EM1 vs GX7 face detection...

Discussion in 'This or That?' started by Ray Sachs, Nov 24, 2013.

  1. Ray Sachs

    Ray Sachs Super Moderator

    Apr 17, 2010
    Near Philadephila
    I've done some user impressions and some comparison between the EM1, EP5, and GX7 over the past couple of months. I recently decided to buy the GX7 but I still have a loaner of the EM1 and, with a bunch of family coming in for Thanksgiving, I'm gonna be doing a lot of candid portraits at the family gathering. So I decided to do a LOT of back to back shooting with the two cameras to really test the face detection capabilities of the two cameras since I'll have the option to shoot with either/both during the holiday.

    In short, the EM1 is notably better. The GX7 only has one setting for face detection while the EM1 has settings for general face, near eye, right eye, or left eye. I generally just leave the EM1 set for near eye focus since I can't imagine a situation where I wouldn't want that to be the target. I did a lot of shooting of my wife and some of myself in a large wall sized mirror. And while both did an OK job, the GX7 was really random as to which part of the face it focussed on. Sometimes it would get an eye but it was more likely to get a nose or, in my case, a beard, or even the frames of eyeglasses. I did all of these with the Olympus 75mm wide open at f1.8 so the DOF was very narrow. The EM1 just about always nailed the close eye, shooting through eye-glasses, missing protruding chins or noses and getting the eye. The GX7 just seemed to get whatever was closest or most prominent. Now for longer shots, like half body shots or farther, either will be just great. But for real close up head shots or head and shoulder shots, I have to say the EM1 is notably better.

    One thing to note though is that the GX7 is better than the EM1 at nailing focus more quickly in lower light. The EM1 does well in this regard, but the GX7 is sort of ridiculous. So in low enough light that the cameras are struggling at all for focus, the advantage shifts to the GX7. Also, I've seen questions raised about whether both cameras also EXPOSE based on the identified face and I can't attest one way or the other. I was shooting in somewhat low light (all of these were indoor shots in ambient light in the evening) and light levels were even enough that there were no really challenging situations for getting exposure right. So there may be an advantage one way or the other in really tough exposure situations, but I can't tell you whether there is or isn't based on my experience...

    I think I'm gonna mostly be doing my candid portraits over Thanksgiving weekend with the EM1 rather than my GX7.

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  2. pdk42

    pdk42 One of the "Eh?" team

    Jan 11, 2013
    Leamington Spa, UK
    I've been pretty impressed by the face detection on my E-M5 and E-PL5. Seems a lot of experienced photographers sneer at such gimmickry though!

    However, for fast moving events, I think it's far better than manually-chosen AF points or even MF.
  3. Amin Sabet

    Amin Sabet Administrator

    Apr 10, 2009
    Boston, MA (USA)
    I think what you've said here isn't well enough known but has been true of Olympus and Panasonic cameras for a pretty long time now, not just these two models. Panasonics have always been better at focusing in low light, and for the last few generations have been unbelievable at locking focus in low light (better than all of the DSLRs I've owned at the same time), while Oly has been better at face detection at least as long as they've offered the choice of near eye priority.

    They do and as far as I know they have done so since the earliest models. Here's an old example. I mounted the Zuiko 17mm lens on the Panasonic GH1 in 'P' mode and snapped four photos, two in 'Dynamic B&W' mode and two in 'Standard' (color). All were in-camera JPEGs with automatic exposure. On the left, you can see the results using face detection. On the right are the results using center point AF to focus on my wife, followed by recomposition:

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  4. New Daddy

    New Daddy Mu-43 Regular

    Jan 24, 2011
    Thanks for the informative test!

    I think at some point Panasonic/Olympus should clarify the metering methods on the LCD display. (Yes, the metering bias for face in face detection AF is documented in the manual at an obscure place, in smaller fonts, if I remember correctly.) When the AF point is set to face detection or tracking, I think the user-set metering mode is completely overridden by focus point-weighted metering. It'd help people to remember if the metering icon were to change to a different shape (from the usual three types) in such situation.

    DSLRs obviously have only the limited OVF to overlay these kinds of information, and it's understandable that DSLRs with face detection and face-weighted metering can't deliver the info to the user. (Yes, DSLRs with face-detection also have face weighted-metering, if I remember correctly.) But mirrorless has the great real estate in LCD/EVF to display some kind of cue to the user that now the metering mode has shifted to bias for the face!
  5. Amin Sabet

    Amin Sabet Administrator

    Apr 10, 2009
    Boston, MA (USA)
    I'm not aware of any DSLRs that do face detection outside of "live view" mode. In other words, if you're composing using the OVF, face detection isn't happening.
  6. New Daddy

    New Daddy Mu-43 Regular

    Jan 24, 2011
    Yes, you're right. It was a hastily written sentence. But in any event, DSLRs that do face detection in live view mode do bias for the face in metering.
  7. Ray Sachs

    Ray Sachs Super Moderator

    Apr 17, 2010
    Near Philadephila
    I was an experienced photographer once who initially sneered at auto-focus and even aperture priority mode! I got over it. When face detection works, there's nothing like it for candid portraits and maybe even for formal portraits (although I don't do formal ones).

    I actually worked in a camera shop selling gear when Minolta introduced the first AF SLR, back in 1985. You should have heard the sneers and jeers from the various sales people in there (myself included). Pretty impressive from a technical standpoint, but terrible by today's standards and we couldn't understand why you'd want to give up control of focus to the camera! Times change...

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  8. GaryAyala

    GaryAyala Mu-43 Legend

    Jan 2, 2011
    I just shot a play with the EM1 and face detection ... I am very impressed and pleased. (First time I've used face detection.)

  9. New Daddy

    New Daddy Mu-43 Regular

    Jan 24, 2011
    How about using GX7's pinpoint focus to lock focus on the eye? Would it be too cumbersome?
  10. Ray Sachs

    Ray Sachs Super Moderator

    Apr 17, 2010
    Near Philadephila
    It would be an alternative to face detection but if face detection is working it's definitely a lot faster and easier than trying to line up the eye with the pinpoint target...

  11. b_rubenstein

    b_rubenstein Mu-43 All-Pro

    Mar 20, 2012
    Melbourne, FL
    On the Face Detection exposure bias, when face detect was off what was the camera focusing on? Or was it a focus and recompose?
  12. Dave in Wales

    Dave in Wales Mu-43 All-Pro

    Nov 5, 2011
    West Wales
    One thing to note though is that the GX7 is better than the EM1 at nailing focus more quickly in lower light.

    Out of interest Ray, was the latest firmware, 1.1, loaded into the EM1.......ie AF improvement in low light.
  13. RoadTraveler

    RoadTraveler Mu-43 All-Pro

    Nov 23, 2012
    I'm not about to give up autofocus, it works too well most of the time. Having said that, you guys at the camera store knew plenty back then…

    About 9 years ago I was still using with manual focus rangefinders (along with autofocus SLRs) for the benefit of total control… and over the past few weeks I purchased two manual focus m4/3 lenses that I'm really enjoying.

    Though I'd also like if face detection and continuous autofocus worked better on my Panasonics.

    Thanks for the tests and information sharing guys.
  14. isabel95

    isabel95 Mu-43 Top Veteran

    I've been fighting the GX7 vs. EM1 decision process and have been leaning towards the GX7 for the silent shutter release because I do a lot of stealth people shooting at meetings - I love living the lcds on my micro 43 cameras and shooting from my lap so people don't pose. There's nothing worse than a posed picture!

    I've always felt that my GH2 was quicker to catch focus than my e-pl5, but found the 20mm lens was a pain with its hunting no matter which camera I used.

    Your observation that the GX7 is better in low light has pushed my decision over the edge - I do a lot of low light too!

    I'm a left-eyed shooter and am going to have to get used to that viewfinder placement!