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Thread: C-AF TR with OM-D E-M1 + Sigma 19/2.8

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    C-AF TR with OM-D E-M1 + Sigma 19/2.8

    OM-D E-M1 was set to C-AF TR with 5 FPS continuous shooting @ f/2.8.
    I focused on the white car in the first frame, then kept the shutter pressed until the last image for 11 frames.
    The camera was on a tripod and didn't move, but the E-M1 successfully tracked the white car across the entire frame in focus!







    With best regards, K-H.
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    Re: C-AF TR with OM-D E-M1 + Sigma 19/2.8

    Thank you I think that I can sell my Canon 7D now

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    Re: C-AF TR with OM-D E-M1 + Sigma 19/2.8

    a black car would be harder to trace

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    Re: C-AF TR with OM-D E-M1 + Sigma 19/2.8

    Quote Originally Posted by mmbma View Post
    a black car would be harder to trace

    Well, not really, as long as it is different from the background color.
    I read somewhere that continues AF tracking works of colors not shapes.
    Please correct if that was wrong. Thanks.
    With best regards, K-H.

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    Re: C-AF TR with OM-D E-M1 + Sigma 19/2.8

    EM1 uses phase detect in continuous shooting. I was just being a smart ***

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    Re: C-AF TR with OM-D E-M1 + Sigma 19/2.8

    Quote Originally Posted by mmbma View Post
    EM1 uses phase detect in continuous shooting. I was just being a smart ***
    Is that true for native m4/3rds lenses also? And doesn't subject tracking work better (in terms of accuracy at least) with CDAF?

    I'd be interested in exactly how the E-M1 is working here.

    Cheers

    Brian

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    Re: C-AF TR with OM-D E-M1 + Sigma 19/2.8

    This is what DPReview has to say about the E-M1 and C-AF+TR: 7. Autofocus

    Continuous AF and tracking use a combination of phase detection and contrast detection.
    Kind regards.
    Bart ...

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    Re: C-AF TR with OM-D E-M1 + Sigma 19/2.8

    Quote Originally Posted by Knorp View Post
    This is what DPReview has to say about the E-M1 and C-AF+TR: 7. Autofocus



    Kind regards.

    Sure, but how does the camera recognize what to track with PDAF and CDAF?
    I think that was the question. So do they use color or shape?
    With best regards, K-H.

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    Re: C-AF TR with OM-D E-M1 + Sigma 19/2.8

    Quote Originally Posted by k-hawinkler View Post
    Sure, but how does the camera recognize what to track with PDAF and CDAF?
    I think that was the question. So do they use color or shape?
    I'd say contrast; contrast is enhanced both by colors and light and good contrast helps to form clear shapes. I don't think that you can make a distinction between shapes and colors. They go together. At least when it comes to the CDAF part of the equation.

    If that is of any indication : on previous Olympus MFT bodies, increasing saturation and contrast (for instance using the "vivid colors" picture style with +2 for the contrast, instead of "natural" or worse "muted" colors) was yielding better results for CAF; it would be interesting to see whether that trick improves the number of keepers on the E-M1 too.

    As for PDAF, they work with special pixels on the sensor; I don't think that type of pixels are able to pick colors ?

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    Re: C-AF TR with OM-D E-M1 + Sigma 19/2.8

    Karl-Heinz can you post some in-focus small crops of a few frames and some out-of-focus areas in the same frames?
    I'm just concerned that the 19mm Sigma at that distance is getting so much in-focus the evidence of actual tracking isn't clear.

    Compare with Don Parrot's recent doggie post on DPReview where his choice of lens, distance and aperture makes everything completely obvious.

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    Re: C-AF TR with OM-D E-M1 + Sigma 19/2.8

    Quote Originally Posted by Ulfric Douglas View Post
    Karl-Heinz can you post some in-focus small crops of a few frames and some out-of-focus areas in the same frames?
    I'm just concerned that the 19mm Sigma at that distance is getting so much in-focus the evidence of actual tracking isn't clear.

    Compare with Don Parrot's recent doggie post on DPReview where his choice of lens, distance and aperture makes everything completely obvious.

    Thanks for the question. Good points.
    So how do I know that the camera tracked?

    Well, once the E-M1 has achieved initial focus in C-AF TR mode it indicates the area with a green wire rectangle in the viewfinder. Keeping the shutter pressed and requiring focus for taking another picture, a new green wire rectangle will appear in the next frame as well. And so on. I saw the green wire rectangle move with the car across the entire frame although the camera was stationary on a tripod. All I did after the initial focus was to keep the shutter pressed down.

    Another test for continuous AF tracking is to focus on a certain object, like an apple on a tree, or the label on an hummingbird feeder. Then rock the camera gentle back and forth. The green wire rectangle will try to stay on the initial object. In this test the E-M1 is much more successful than the E-M5 as it stays focused on the initial object much longer.

    Please, try it if you have any of the cameras.

    BTW, C-AF behaves quite differently. Keeping the shutter halfway pressed while slowly rotating the camera, then briefly pausing, rotating again, etc the camera will focus on whatever it is currently pointed at.

    I hope this helps. Thanks again for your question.
    With best regards, K-H.
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    Re: C-AF TR with OM-D E-M1 + Sigma 19/2.8

    Quote Originally Posted by k-hawinkler View Post
    OM-D E-M1 was set to C-AF TR with 5 FPS continuous shooting @ f/2.8.
    I focused on the white car in the first frame, then kept the shutter pressed until the last image for 11 frames.
    The camera was on a tripod and didn't move, but the E-M1 successfully tracked the white car across the entire frame in focus!
    subaru (2nd car, with fake or real air intake on its hood) looks to be in focus too, so you simply had big DOF... now try the same feat w/ P35-100/2.8 @ 100 & 2.8.. so that we can really see that DOF is moving along w/ the subject that you are tracking

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    Re: C-AF TR with OM-D E-M1 + Sigma 19/2.8

    Well, I satisfied my own curiosity and won't make a career out of it.
    Please, let us know about your experience.
    Thanks.
    With best regards, K-H.

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