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[Noob Question] About E-M1 and Landscape

Discussion in 'Olympus Cameras' started by dbzkid777, Dec 22, 2014.

  1. dbzkid777

    dbzkid777 Mu-43 Regular

    55
    Jul 26, 2014
    Question about the grid thing vs. Aperture.

    I get how Aperture works in a basic sense.
    Low Aperture, more DOF, use a single small green square on subject (from the grid).
    High Aperture, less DOF, use all green squares (from the grid).

    What happens if I have my lens at the lowest aperture and I make the grid thing all highlighted?
    Will it just have high DOF and just automatically focus on an object? Or will it be more landscapy?

    I kinda don't get how that square green grid thing works.

    Thanks!
     
  2. bassman

    bassman Mu-43 Top Veteran

    678
    Apr 22, 2013
    New Jersey
    Scott
    Any lens can only focus at a single distance from the camera. Highlighting the focus points by scrolling around merely tells the camera which points to consider when it's trying to focus. It has no bearing whatsoever on the DoF, which for your E-M1 depends only on the selected aperture, focal length and distance to the focus point.
     
  3. bikerhiker

    bikerhiker Mu-43 All-Pro

    Dec 24, 2013
    Canada
    David
    First we need to understand the basics of photography. 99% of photography is about capturing blur while only 1% is technically sharp. Your autofocus system is tuned to lock on to that plane of focus. In a sense, your focused point is just 1 plane in space, because what we are dealing with is only a 2 dimensional art. What I think you're alluding here is that you want the camera to work in 3 dimensional way telling you that this 1% plane is expanding to more than 1% as you stop down the aperture. Unfortunately though, it doesn't work that way and it won't because what the camera is seeing and recording is always 2 dimensional.

    So what does stopping down aperture does? It allows the area around the focus area and give the illusion of sharpness, the illusion of depth. As you stop down the aperture (number becomes larger) your depth of field increases until it reaches the diffraction point. As you open up the aperture (number becomes smaller), your depth of field decreases until you experience increased longitudinal chromatic aberrations (LOCA) or bokeh fringing making the whole image look kind of soft.

    The easiest way to preview this effect is to use "FOCUS PEAKING" feature of your E-M1. I use it quite often and basically replaces the Depth Of Field preview because it gives an accurate representation of where my depth of field zone is. Make sure you're in manual focus mode. As you move your focus point, you will notice that a white band of regions about 1/3 in front and 2/3 back are moving with that 1 plane where you want to focus. This is better then the grid system as it won't show it in a somewhat 3 dimensional way as focus peaking does. Lots of light works best this way.

    Does this helps..
     
  4. dbzkid777

    dbzkid777 Mu-43 Regular

    55
    Jul 26, 2014
    So is there no point in the grid squares then?
    Should I always have it "all highlighted" and focus on Aperture for the DOF?
     
  5. letsgofishing

    letsgofishing Mu-43 Veteran

    352
    Nov 21, 2012
    South Africa
    Mike Kaplan
    The grid squares are for "telling" the camera on which area of the scene you want to focus - I suggest in your case use the centre square.
    If you want as much of the scene as possible to be in focus, then use a small aperture like f8 or f11,
     
    • Agree Agree x 1
  6. Klorenzo

    Klorenzo Mu-43 All-Pro

    Mar 10, 2014
    Lorenzo
    Hi, DOF depends on:
    - aperture
    - focus distance
    - focal length
    - sensor size

    It is not directly related to the green squares. The AF controls only one variable: the focus distance.
    If you use a single square the AF will change the focus distance to get that single part in focus ("maximize the contrast").
    With more squares I suppose that the camera tries to focus all those squares at the same level possibly giving you more DOF if those areas are at different distances from the camera. But if you are using a small aperture you'll get a small DOF anyway unless you focus on the far background. AF does not change aperture or maybe it does in iAuto, I do not know.

    The problem with many squares is that the camera will "randomly" pick a few (depending on the contrast I suppose) and, for example, in a portrait it could choose to focus on the street sign in the background instead of the subject face.

    AF needs contrast to work and with many squares it is easier to find some somewhere so you'll often get the picture more easily without too much focus hunting. If you are using a medium aperture (from 4 to 8) you will have a lot of DOF and it doesn't matter much the exact focus distance (unless you are really close to the subject). So, in practice, many squares work just fine. I also suppose the squares choice is quite smart favouring closer areas over distant ones.

    A lot of people eventually switch to use the central small square only (with focus and recompose) or using a single small square moving it around to have more control on the focus placement.
    But in this way you have to place the box exactly over an high contrast area because the AF will ignore everything else. So, for example, the contrast on the cheeks or on the front may be too low for the AF to work and you will have to move the box over the eyebrows, half-press the button to focus, and recompose.
     
    • Like Like x 1
  7. bikerhiker

    bikerhiker Mu-43 All-Pro

    Dec 24, 2013
    Canada
    David
    If you select to have it all highlighted, you are telling your camera to automatically select a focus point for you, which is excellent for point and shoot or for someone who doesn't know a lot about your camera but want them to take a photo of you or doing your own selfie. It also helps you concentrate on aperture for DOF control because the computer will base the starting focus point on which aperture you have selected for the shot to give the best DOF coverage. It's only when you're doing critical DOF work with f/1.8 of your 45mm lens is when you want to take it out of all highlighted and use single point focus.