Samsung Digimax V700

Discussion in 'Samsung' started by Sylvain Menard, Jun 7, 2005.

  1. Anyone tried it yet? How good is the flash with this camera? Is the video
    stabilizer effective? I tried to find a video sample from this camera but
    found none on the net...
    Sylvain
     
    Sylvain Menard, Jun 7, 2005
    #1
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  2. Yes, I have just seen this yesterday! Another cool feature of the V700 is
    that you can "pause" a video. I have just seen on dcresource a Kodak camera
    that will be shipped in july. The camera is Kodak EasyShare V530 and it is
    supposed to allow zooming during filming! Also coming is the Casio
    introduces Exilim EX-S500
    which is also equipped with digital image stabilizer for movie! Too many
    camera with cool feature are getting out, I think I'll wait a couple of
    month before choosing one...

    Sylvain
     
    Sylvain Menard, Jun 11, 2005
    #2
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  3. Sylvain Menard

    Tony Hwang Guest

    Hi,
    Digital stabilizer? What's good for it.
    My old Sony TRV900 has optical stabilizer.(real thing)
    Tony
     
    Tony Hwang, Jun 11, 2005
    #3
  4. Sylvain Menard

    SamSez Guest

    Invariably? Yes. Digital is limited to increments of the pixel
    spacing unless it interpolates. Optical is not. Can closed.
     
    SamSez, Jun 12, 2005
    #4
  5. Shifting an image by a fraction of a pixel is pretty easy. I wouldn't
    conclude that no camera with digital stabilization is capable of this.

    I think the important difference is this: When optical stabilization is
    working properly, the image is stationary on the sensor, and each
    individual frame of video is sharp. When only digital stabilization is
    used, the image is continuously moving on the sensor, and each single frame
    is blurred by that motion. The stabilization process can remove the
    large-scale movement over many frames, but it can't fix that blur.

    All of the still cameras that I know of with image stabilization use
    optical stabilization in the lens, except for the one that does the
    stabilization by mechanically moving the sensor.

    Nobody uses digital image stabilization in a still camera, because if
    you're taking one still image you want that one image to be sharp.
    It's not useful to be able to align a sequence of blurry images.

    Dave
     
    Dave Martindale, Jun 13, 2005
    #5
  6. Dave Martindale wrote:
    []
    I can cite one possible exception to this - when taking video the Nikon
    Coolpix 8400 can use electronic image stabilisation (it has no optical
    stabilisation). However, when it does this the video resolution is a
    maximum of 640 x 480 pixels, far lower than the basic sensor resolution
    (8MP).

    Of course, you could argue that this /isn't/ a still camera in this mode,
    and in any case the slight blur may be much less noticeable in a moving
    image!

    Cheers,
    David
     
    David J Taylor, Jun 13, 2005
    #6
  7. Sylvain Menard

    SamSez Guest

    Actually, shifting an image by a fraction of a pixel is impossible
    -- 'unless it interpolates' -- as I originally said.

    And if it does interpolate, then it is going to give a worse image
    than one created by shifting the optical path.

    That's one factor.

    Add to that your point -- to state it somewhat differently -- the fact
    that optical stabilization can keep the image centered on the
    same pixels over the entire duration of the exposure, and the
    advantage of optical is obvious.

    The only way a digital scheme would even come close to optical
    would be if were able to capture many frames over the duration
    of the exposure, shift each slightly to eliminate the motion, and
    composite them into a single image. But if you really could
    capture multiple frames over the exposure, that implies that the
    longer exposure wasn't really necessary in the first place. And
    even if it is done that way, there is still the issue of image
    degradation due to interpolation effects.
     
    SamSez, Jun 13, 2005
    #7
  8. If you're shooting video, it's useful to remove the large-scale motion
    even if the camera can't fix the blur.

    Dave
     
    Dave Martindale, Jun 13, 2005
    #8
  9. "Interpolation" is a vague term that can refer to any method to
    calculate new values from existing data. It may lose information, or
    it may not - it depends on the technique used.

    Shifting an image by a fraction of a pixel would be done by an image
    resampling technique. Image resampling is a type of interpolation, but
    it's done with well-studied algorithms and on data whose spatial
    frequency content is known. *This* can be done with no visible loss of
    information at all.

    Your argument is basically that shifting using resampling will
    necessarily make the image quality worse - and that's just not true.

    Dave
    This is the real reason that optical stabilization is better.

    Dave
     
    Dave Martindale, Jun 13, 2005
    #9
  10. Yes, indeed. The results on video are very good for a stills camera!

    Cheers,
    David
     
    David J Taylor, Jun 13, 2005
    #10
  11. Sylvain Menard

    SamSez Guest

    No, not any resampling -- partial pixel shift resampling. I've never
    seen it done that doesn't result in diagonals looking worse than prior
    to the resampling.
     
    SamSez, Jun 13, 2005
    #11
  12. What algorithm was used for the resampling?

    I'd offer to run a test on some sample image of your choice using my own
    resampling software (which is nothing special, but I know how it works
    internally) except my Linux machine is currently being reconstructed.

    If you're interested in the experiment, send a sample image with
    diagonals and I'll try it when the software is running again.

    Dave
     
    Dave Martindale, Jun 14, 2005
    #12
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