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Thread: A900 bug?

  1. #1
    Spyder
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    A900 bug?

    I've already described this on another forum but hardly got any answers, so I'm trying here...

    I've been using the A900 for 5 days now ( I've used the A700 for over one year ). A common practice I have is to use spot focus, half press the shutter button to lock it on the spot I want and recompose ( not the best way but works well in most situations ). When I do that I expect the exposure values ( aperture or shutter speed ) to auto adjust for the recomposed frame. My doubt is that with the A900 that works well for both center weighted and spot metering modes, but for multi-segment metering, the exposure is also locked with the focus and doesn't auto-adjust when I recompose ( I'm not pressing the AEL button...! )!
    I'm wondering if that's normal for the A900 or it's a defect/bug in my camera.
    I'd appreciate comments on your experience!
    Thanks

  2. #2
    Spyder
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    Sorry, guys...!

    On page 70 of the A900 Manual it says it's supposed to lock exposure with the focus lock when in matrix mode!!! I've read the Manual but never saw that...

  3. #3
    Member picman's Avatar
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    Re: Sorry, guys...!

    Quote Originally Posted by Spyder View Post
    On page 70 of the A900 Manual it says it's supposed to lock exposure with the focus lock when in matrix mode!!! I've read the Manual but never saw that...
    I don't think it is a bug. I had the same observation about my A700 at first and asked David Kilpatrick over at photoclubalpha. See this thread

    http://www.photoclubalpha.com/forum/...7&p=2837#p2837

    Of course that is about the A700.

    However, on the A900, the easiest way for me is to focus, hold focus lock button on the lens, let go of the shutter button, recompose and now press the shutter button again. Metering is freed at the moment you let go of the shutter button. Maybe others have quicker/better methods but doing it this way has become second nature for me.

    Cheers, Bob.

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    Re: A900 bug?

    I also focus and re-frame with my A900. With manual focus, you could always use the ground glass, but with autofocus, its like using a rangefinder with a central spot. What I want, which is what I think you want, is to completely separate the AF from the exposure setting.

    What I've done is to set the option AF with Shutter to Off so I autofocus with the rear controller. You're forced to use the center spot and single shot AF.

    If you set the AF to Local with AF w/shutter to Off, and select a non-central focus point using the Local focus area setting, the camera won't act on it! The rear controller only seems to activate the center spot. This is what I reported as a bug. Local mode seems to work only when focusing with the shutter release. With the camera set to Wide area mode, again, only the center focus seems to activate. I haven't noticed any other points being selected by the camera.

    With the camera set to Continuous and AF w/shutter to Off, the rear controller still only seems to work in single-shot focus mode. I haven't tried it on a moving object, but you never get the brackets around the focus locked indicator. The way I've tried it is to focus on something and then move the camera around that object. With AF w/shutter to On, the brackets will come on and the center spot will blink. I'm taking this to indicate the Continuous AF is working. With AF w/shutter to Off, the brackets never come on.

    I think the solution is simple. Copy how the rear controller worked on the Minolta 7D. When you select an autofocus point with the rear controller, the camera automatically focused on that point. Its a great design! I hope Sony can offer this in a firmware revision.

    Here's how I think it should work. In Single shot mode, you select the autofocus point and the camera will focus on it. In Continuous mode, you select the point and the camera focuses on it and then tracks from that point on. Wide mode should be renamed Auto mode or something like that, meaning the camera picks the point.

    If anyone knows how to send this info to Sony, please let me know. I'm not convinced the support person I spoke with really understood what I was talking about and couldn't give me an emial address to send in a problem description.

  5. #5
    Senior Member Braeside's Avatar
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    Re: Sorry, guys...!

    Quote Originally Posted by picman View Post
    I don't think it is a bug. I had the same observation about my A700 at first and asked David Kilpatrick over at photoclubalpha. See this thread

    http://www.photoclubalpha.com/forum/...7&p=2837#p2837

    Of course that is about the A700.

    However, on the A900, the easiest way for me is to focus, hold focus lock button on the lens, let go of the shutter button, recompose and now press the shutter button again. Metering is freed at the moment you let go of the shutter button. Maybe others have quicker/better methods but doing it this way has become second nature for me.

    Cheers, Bob.
    Bob, With the A900, what you suggest appears to only work when NOT using Matrix metering? There does not appear to be any point in holding the focus lock button on lens as you can get the same effect just half pressing the shutter and that locks the focus. Am I missing something that you are doing?

    To be clear, in matrix metering, holding focus with the lens button also locks the exposure.
    David Anderson

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    Member picman's Avatar
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    Re: Sorry, guys...!

    Quote Originally Posted by Braeside View Post
    Bob, With the A900, what you suggest appears to only work when NOT using Matrix metering? There does not appear to be any point in holding the focus lock button on lens as you can get the same effect just half pressing the shutter and that locks the focus. Am I missing something that you are doing?

    To be clear, in matrix metering, holding focus with the lens button also locks the exposure.
    David, I never use matrix metering, only center weighted and spot. However, yes you are right it does not work for matrix metering because in that mode, holding the lens button locks both focus and metering, but so does half pressing the shutter.

    Re the half press on the shutter to lock focus, again you are right. My reason for doing it my way with the lock button on the lens and not the shutter is innocent enough. I simply find it personally more convenient to press the lock on the lens firmly while recomposing than to be careful to press the shutter only lightly and hold this light pressure while thinking about the shot. Pressing firmly on the lens-button somehow is easier to forget about and get on with the rest. But again, it is just a personal thing.

    Cheers, Bob.

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    Senior Member Braeside's Avatar
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    Re: A900 bug?

    Thanks for the clarification Bob, I just thought I was missing a trick.

    I don't think 2 people use the camera in the same way here.

    Cheers again.

    PS
    After a beautiful sunny day, which I had to spend indoors waiting for delivery of my 70-400 SSM lens, the minute it arrived the rain has come on and looks set for the foreseeable future.
    David Anderson

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    Senior Member Braeside's Avatar
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    Re: A900 bug?

    Quote Originally Posted by Spyder View Post
    I've already described this on another forum but hardly got any answers, so I'm trying here...

    I've been using the A900 for 5 days now ( I've used the A700 for over one year ). A common practice I have is to use spot focus, half press the shutter button to lock it on the spot I want and recompose ( not the best way but works well in most situations ). When I do that I expect the exposure values ( aperture or shutter speed ) to auto adjust for the recomposed frame. My doubt is that with the A900 that works well for both center weighted and spot metering modes, but for multi-segment metering, the exposure is also locked with the focus and doesn't auto-adjust when I recompose ( I'm not pressing the AEL button...! )!
    I'm wondering if that's normal for the A900 or it's a defect/bug in my camera.
    I'd appreciate comments on your experience!
    Thanks
    I found that there is a way to do this in multi-segment metering - you half press to get focus then release the shutter button and press the AF/MF button, that puts the camera into manual focus and in effect focus locked while you hold it (if you have AF/MF control set to the default of HOLD). You can now recompose and the metering will follow even in multi-segment and then press the shutter to take pic.
    David Anderson

  9. #9
    Senior Member Braeside's Avatar
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    Re: A900 bug?

    Quote Originally Posted by Cerebus View Post
    Here's how I think it should work. In Single shot mode, you select the autofocus point and the camera will focus on it. In Continuous mode, you select the point and the camera focuses on it and then tracks from that point on. Wide mode should be renamed Auto mode or something like that, meaning the camera picks the point.
    That is exactly how it works in AF C mode if you use the shutter button to do the focus,your selected point in Local mode is used for the AF C focus point, though the actual point selected only shows up once as the shutter is half pressed.

    Pressing the joystick button always puts the camera into AF S and forces the centre point to be used regardless, so you have to use the shutter half press.
    David Anderson

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