Face detection woes - how does it work?

Discussion in 'Open Gear Talk' started by Armanius, Feb 29, 2012.

  1. Armanius

    Armanius Bring Jack back!

    Jan 11, 2011
    Houston, Texas
    Jack
    I was taking many photos this past weekend using the Panasonic GF2 + Oly 45/1.8 combo. Had the camera set on face detection. There were a number of times that I had focus confirmation from the GF2, but the subject's face came out fairly soft (camera set on aperture priority, f1.8, auto ISO yielding shutter speeds of 1/100).

    Here's an example of a 100% crop, and the subject wasn't even moving. Her entire face was soft, not just the eyes:

    Face_detection_woes.

    It makes me wonder if face detection (or at least on the GF2) is the best way to take photos of people (particularly when shooting wide open at large apertures) as opposed to using spot focus by either moving the focus point around the frame, or using the center point and then recompose.

    It's my understanding that face detection will focus on the eyes of the face. Or at least that's the idea. I know on the EP3, the user can specify that the focus should be on the eye, and even which eye. I am wondering if my GF2 was trying to focus on the entire face, as opposed to just the eye. And because the 45/1.8 has such a shallow DOF, by trying to focus on the entire face, the result is that nothing ends up being on focus.

    Anyone else experience lackluster performances from their cameras while using face detection?
     
  2. Luckypenguin

    Luckypenguin SC Hall of Famer

    Dec 24, 2010
    Brisbane, Australia
    Nic
    What was the shutter speed, Armando? It does look there is some motion blur (the points of reflected light in the eyes, for example).
     
  3. Ray Sachs

    Ray Sachs SC Legend

    Sep 21, 2010
    Not too far from Philly
    you should be able to figure it out...
    FWIW, I found face detection all but unusable on the previous generation of m43 cams (gf1, ep2) but vastly improved with the current gen, at least of Olympus. I've used it with really good results with the EPL3 and EP3. I don't recall trying it when I had the GH2 and I know I didn't mess with it for the short time I played with a G3, but I'd imagine its better in those too, just based on the impressive overall speed of the camera's processing. Not sure about the GF2, but it might just be overmatched...

    -Ray
     
  4. Armanius

    Armanius Bring Jack back!

    Jan 11, 2011
    Houston, Texas
    Jack
    1/100. Maybe she did move. But pretty sure she didn't. Maybe I did? Hmmm ... I guess I might be getting to the age of needing IBIS!
     
  5. drd1135

    drd1135 SC Hall of Famer

    Jul 13, 2011
    Southwest Virginia
    Steve
    A bit of an aside her, but I notice that Photoshop Elements 10 has great Face detection. It finds every face in my shots and wants to identity them. I supoose if it works so well because it has more time to actually process an image than a camera does.