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Thread: Out of focus causes?

  1. #1
    Senior Member Rawfa's Avatar
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    Out of focus causes?

    Hi,

    I've been doing some indoor tests with the NEX5 and I've been finding out a considerable amount of out of focus shots even when I shoot at 1/50 shutter speed. To keep me from increasing the ISO I've started out shooting 1/10, which with a steady hand I have always managed to do with the GF1 and the 20mm 1.7. I've progressively increased the shutter speed with the NEX+16mm but I was surprised to see more than the usual amount of out of focus shots. And finally at 1/50 I've started wondering if there is some incamera option that is causing this, because at 1/50 is pretty darn hard not to be able to get good focus. My other thought was "Maybe this doesn't have anything to do with shutter speed, maybe this camera just has a hard time locking focus in dim light".

    Any thoughts?

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    Re: Out of focus causes?

    The focusing (though CDAF) is OK.

    Primary cause for your problem (mine as well) are:

    1. The pathetic ergonomics.

    2. The shot gun shutter, especially when handholding, that startles the holder.

    To check this, set the self timer and make a snap at 1/50s while the camera is resting on something solid (no need for even a tripod). You can use the half tilt LCD as the support (a major use of that LCD, IME).

    In reality, I need at least 1/160s to get a reasonably sharp image for street shots with a NEX5. This negates all the advantages of the high ISO that NEX could provide.

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    Senior Member Rawfa's Avatar
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    Re: Out of focus causes?

    Thanks, Vivek. Im going to give it a try. Though it will really suck if 1/50 is the lowest shutter speed for hand held shots. Now Im REALLY glad Ive ordered an adapter for my leica m and my pentax lenses.

  4. #4
    01af
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    Re: Out of focus causes?

    Quote Originally Posted by Rawfa View Post
    Any thoughts?
    Can you tell the difference between out-of-focus blur and camera-shake blur? Sorry, but for some reason I'm under the impression you cannot. Otherwise I'm afraid I don't really understand your problem. Focus (or lack thereof) has nothing to do with shutter speed. Maybe you can show a picture or two? Is auto-focus accuracy okay in bright daylight?

    Anyway, it generally is a bad idea to risk camera shake in hand-held shots just to avoid higher ISO settings. Image stabilisation reduces camera shake so it helps but cannot eliminate it entirely. In poor light, just crank up the ISO setting when shooting hand-held!

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    Senior Member douglasf13's Avatar
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    Re: Out of focus causes?

    I can't speak for the 16mm, because I haven't used it enough, yet, but with my various 35mm lenses, I find that somewhere around 1/20 or 1/25 is about the cut off point for me. One thing that I do when shooting, which helps a lot, is I put my right thumb on the angled part on top of the camera that is directly to the left of the NEX-5's video button. I actually put a little piece of leatherette there for traction.

    You may also consider trying out a half-case for a better grip.

    I agree with Vivek that the shutter is a little ridiculous in power. I personally wish that they didn't make the camera 7fps, because I'm sure that is why the thing is so powerful. Regardless, you should be able to handhold at slower speeds than your mentioning, so a tweak in form should help.

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    Re: Out of focus causes?

    Quote Originally Posted by 01af View Post
    Can you tell the difference between out-of-focus blur and camera-shake blur?
    Sadly, in case of NEX, I could not either.

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    Re: Out of focus causes?

    You could determine if it is focus or shake by:

    manually focusing for the shot
    shoot at high ISO to get a faster shutter speed and see if you get a sharp shot

    If both of those are in focus I would suggest it is camera shake.

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    Re: Out of focus causes?

    Quote Originally Posted by TEBnewyork View Post
    You could determine if it is focus or shake by:

    manually focusing for the shot
    shoot at high ISO to get a faster shutter speed and see if you get a sharp shot

    If both of those are in focus I would suggest it is camera shake.
    It ain't that simple with the NEX. See post #2.

    Handholding shutter speed threshold will vary from person to person.

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    Senior Member Rawfa's Avatar
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    Re: Out of focus causes?

    Many thanks everybody for all the alternative testing. This coming weekend I will have more time to spend with the camera and conduct more conclusive tests.

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    Re: Out of focus causes?

    Quote Originally Posted by 01af View Post
    Can you tell the difference between out-of-focus blur and camera-shake blur? Sorry, but for some reason I'm under the impression you cannot.
    Just shoot something that doesn't move, that should rule out motion blur...or am i missing something?

    N
    A and E mount Too many lenses.

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    Re: Out of focus causes?

    Quote Originally Posted by BackToSlr View Post
    Just shoot something that doesn't move, that should rule out motion blur...or am i missing something?

    N
    Not trying to rule out the object moving but trying to isolate bad focus from the user not holding the camera steady.

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    Re: Out of focus causes?

    I've been surprised by the NEX too WRT getting no motion blur with MF. Getting a sharp shot with holding my G1/GH1 at waist level is not an issue... with the NEX, it is. I agree with Vivek that the shutter and/or the action one uses to trip the shutter is the culprit. I'm trying different strategies for holding and releasing to see if I can mitigate things.

    Cheers,

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    Re: Out of focus causes?

    Quote Originally Posted by Vivek View Post
    The focusing (though CDAF) is OK.

    Primary cause for your problem (mine as well) are:

    In reality, I need at least 1/160s to get a reasonably sharp image for street shots with a NEX5. This negates all the advantages of the high ISO that NEX could provide.
    Perhaps all you are missing is stabilization (16mm is not stabilized either).
    And even though a large shutter in NEX as compared to m4/3 has potential to add to vibrations, it is easy to verify/rule that out. If it was indeed the case the vibrations or loss of IQ would be apparent even on a tripod. A simple experiment should rule that out. I highly doubt it.

    With 16mm DOF is so large that it is unlikely that AF is the culprit either.

    IME, i have had some shots be out of focus but primarily because i am shooting wide open at 50mm f1.4 and the subject moved out of focal plane. Also, the bright view finder image sometimes tricks me into believing that the light is enough, till you see the preview and there is blur (this is different from regular alpha DSLRs where the stabilization saves many shots.). I wish the ISO range could go all the way to 6400 instead of being limited to 1600.

    Cheers,

    N
    A and E mount Too many lenses.

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    Re: Out of focus causes?

    Quote Originally Posted by TEBnewyork View Post
    Not trying to rule out the object moving but trying to isolate bad focus from the user not holding the camera steady.
    Ok. But still static subject would remove one variable. I am suggesting that it should be easy to verify.

    When I shoot macros with NEX, i carry my remote and trigger it remotely to overcome lack of stabilization, maybe something like that could help the OP investigate the matter...

    N
    A and E mount Too many lenses.

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    Re: Out of focus causes?

    Quote Originally Posted by BackToSlr View Post
    Perhaps all you are missing is stabilization (16mm is not stabilized either).
    And even though a large shutter in NEX as compared to m4/3 has potential to add to vibrations, it is easy to verify/rule that out. If it was indeed the case the vibrations or loss of IQ would be apparent even on a tripod. A simple experiment should rule that out. I highly doubt it.



    N,

    No, I do not miss "stabilization" (built in lens or anti shake in cam). I do not plan to buy any Sony zooms with built in anti shake.

    Even without a tripod (see post #2), I see sharp images. It is the shotgun shutter that needs to be muzzled.

    It is a problem with the NEX5. A major one, AFAIC.

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