A dSLR's fastest shutter-speed is really no faster than its flash-sync speed.

Discussion in 'Digital Photography' started by SelfImporantName, Jul 7, 2007.

  1. Considering that a dSLR is using a mechanical shutter, just like the old ones in
    film SLRs, the true fastest shutter-speed is really no faster than its highest
    flash-sync speed -- when the imaging chip is completely exposed without either
    shutter-curtain covering any portion of it.

    Sure, you can crank up the shutter-speed by moving those two shutter-curtains
    closer together, making a very very narrow slit pass in front of the imaging
    chip. But that just means that *anything* that's moving in that image will be
    distorted. Just like in the SLR days. The beating of a bird's wing will be
    unnaturally curved. A circular tire passing by will be elongated and oval. A
    baseball pitcher's arm will be slightly bent in the wrong places. A diver
    falling into a pool of water will be unnaturally shorter or longer than they
    should be. (Or unnaturally distorted diagonally if the shutter curtains in your
    dSLR move horizontally.) The very same problems that we faced in SLR days. This
    problem is no different than if you tried to take your own photo by holding your
    face over a flat-bed scanner and slowly rotating your face while it was being
    scanned. A slower example of how *any* dSLR will not give you a true image of
    anything moving faster than its shutter's flash-sync speed.

    There's just no getting around this mechanical and image-distorting limitation
    in a dSLR. Just like there was no getting around this limitation in last
    century's SLRs. It's built into the very design of it.


    They should always mention this in any reviews on dSLRs, so all those
    "intelligent" pros will also realize they are paying to get last-century's
    faults and limitations.

    It's so nice having an advanced P&S camera that will sync the flash up to
    1/2500th of a second. Proving that that's its true shutter-speed. Zero image
    distortions caused by a mechanically slow shutter-curtain.

    You can easily and simply prove it to yourself by holding your dSLR at 45
    degrees tilt to your monitor and trying to take a picture of the monitor
    display's scan-lines at shutter-speeds faster than its flash-sync speed. You'll
    find a badly bent lighted area in your resulting dSLR image, the higher the
    shutter-speed the more distorted it will become. Instead of a few well defined,
    perfectly even, parallel lines, that you will find when taking that same image
    with a P&S camera that doesn't depend on a mechanical curtain-style shutter. A
    P&S camera can stop/capture the activity of those scan lines or any fast moving
    object accurately, a dSLR shutter cannot, will not.

    (If I had just bought a dslr today and thought about this, I'd be *really*
    pissed about my purchase right now. I wonder why all those other dSLR owners
    never mention this to newbies when it's so painfully obvious.)
    SelfImporantName, Jul 7, 2007
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  2. SelfImporantName

    Ray Fischer Guest

    If you're going to redefine the definition of "shutter speed" to mean
    whatever you want then you prove anything you want. But you won't
    impress anybody.
    Ray Fischer, Jul 7, 2007
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  3. SelfImporantName

    Mike Russell Guest

    Points for an original viewpoint, but ... so? Focal plane shutter
    distortion is nothing new. People are used to it, and accept it as an
    indication of speed. Furthermore, digital techniques can be used to
    minimize the distortion, or transfer it to the less important background, if
    Mike Russell, Jul 7, 2007
  4. SelfImporantName

    Pete D Guest

    Sorry to burst your bubble but your P&S does not have a shutter.
    Pete D, Jul 7, 2007
  5. SelfImporantName

    John Bean Guest

    It *might* have Pete, I'll give him the benefit of the doubt
    on that one.

    It's unlikely though ;-)
    John Bean, Jul 7, 2007
  6. SelfImporantName

    Pete D Guest

    Maybe! Not many do!
    Pete D, Jul 7, 2007
  7. A dSLR can have an electronic shutter in addition to the mechanical one.

    Nikon's older CCD based cameras provide flash synchronization upto the
    highest shutter speed (1/16000).
    Philip Homburg, Jul 7, 2007
  8. Actually, many of the better P&S cameras have shutters. The Sony sensors
    require a mechanical shutter to avoid really nasty smear problems.

    David J. Littleboy
    Tokyo, Japan
    David J. Littleboy, Jul 7, 2007
  9. SelfImporantName

    John Bean Guest

    But to split hairs even finer David, they usually (always?)
    just use the aperture mecanism for the purpose so they still
    don't have a dedicated shutter in the same sense a SLR has.
    John Bean, Jul 7, 2007
  10. You've spent a lot of time and thought exposing this shocking secret;
    did it not occur to you it might be common knowledge?

    Prepare to be astounded by the evening news - "So-called hybrid cars
    have batteries BUT STILL REQUIRE GASOLINE!"
    Scott Schuckert, Jul 7, 2007
  11. SelfImporantName

    Allen Guest

    SelfImporantName wrote:
    <snip self-important ramblings>
    What a perfect choice for a posting name! But did you have to use so
    many lines justifying it? Couldn't you just have posted the obvious fact
    that you are a self-importnat jerk?
    Allen, Jul 7, 2007
  12. SelfImporantName

    dave Guest

    ..............total nonsense deleted............................
    Focal plane shutter travel has not been a factor for more than fifty
    years and you would know that if you only even used, let alone owned,
    one. If you can stop the action there will be no visible distortion.
    Shooting a monitor or TV screen at speeds faster than their refresh
    rate will cause distortion regardless of shutter type.
    dave, Jul 7, 2007
  13. But that's no different to many 35mm point and shoots, at the end of the
    day it's still a shutter - it opens and closes - even if it also acts as
    the iris.
    Gordon Freeman, Jul 7, 2007
  14. I think you are splitting hairs beyond what even I would. Leaf shutters live
    in the lens at the same point as the aperture, but in film cameras, were
    always a mechanically separate structure. I doubt that that design would
    change. (I have taken apart leaf shutter film cameras, but I've never
    disassembled a P&S dcam.)
    Again, a leaf shutter has always been seen as very much the same sort of
    thing as a FP shutter.

    (Four (Agfa folder, Rollei TLR, Fuji GS645S, Mamiya 7) out of five (vs.
    Mamiya 645) of the film cameras here have leaf shutters, so I'm rather
    familiar with the beasts...)

    David J. Littleboy
    Tokyo, Japan
    David J. Littleboy, Jul 7, 2007
  15. SelfImporantName

    John Bean Guest

    Yes and no, Cheap film cameras did this purely to save cost,
    better cameras usually have a "proper" shutter. But even
    high-end digital P&S cameras use this method if they are
    forced to do so, normally they use no shutter of any sort. I
    can't think of any that have a "proper" shutter.

    SLRs - film or digital - invariably use a mechanical

    Anyway it's all a bit moot to the OPs attempted criticism of
    focal plane shutters in SLRs ;-)
    John Bean, Jul 7, 2007
  16. SelfImporantName

    John Bean Guest

    Exactly - a seperate mechanism, seperate controls. Shutter
    and iris are not the same thing. That was all I was saying
    about the lack of *dedicated* shutter, they use the aperture
    blades instead.
    A leaf shutter isn't part of a set of aperture blades, it's
    a seperate, self-contained mechanism. The digital P&S
    doesn't have a leaf shutter; when I said it had no
    *dedicated* shutter I meant it uses the aperture blades to
    perform a similar (but not quite identical) function. No
    leaf shutters that I'm familiar with could match the speed
    range of most digicam shutters, and there's a good reason
    for that.
    So am I. But we weren't arguing about leaf shutters so no
    need to claim bragging rights ;-)
    John Bean, Jul 7, 2007
  17. SelfImporantName

    Tony Hwang Guest

    Tony Hwang, Jul 7, 2007
  18. SelfImporantName

    Alan Browne Guest

    The current world of DSLR's is, simply put, replacing the film with a
    sensor. Surely this occured to you? The "SLR days" are not over.

    For that matter, shutter flash-sync is only as precise as the flash
    duration. If you shoot a large flash (say a Canon 580EX) at 1/64 power,
    then you are in the realm of 10's of microseconds. But the same flash
    shot full power (1/1) will last for over 1 millisecond (slower than 1/1000).
    Alan Browne, Jul 7, 2007
  19. SelfImporantName

    X-Man Guest


    Let me mark this down as reason #157 of why to NEVER purchase a DSLR! I may move
    the to reason #1 position. Who on earth would want a camera that takes photos
    where ANY moving subject is intentionally distorted??? Maybe this is why DSLR
    owners think the way they do, THEY LOVE DISTORTIONS!!!
    LOL!!!!!!!!!!!!!!!!!!!!!!!! No wonder they can't see what's wrong!!! LOL!!!!


    I read the replies of the fool DSLR whiners trying to evade the issue and brush
    it under the carpet. This is PRICELESS!!! LOL!!!!!!!!!!!!!!!!!!!!!!!!! Some of
    them don't even want to think it happens, or that ALL cameras do this!

    This made reading this newsgroup worth it today!!
    X-Man, Jul 7, 2007
  20. Sorry to burst your bubble, but nowhere do I mention nor claim that the P&S
    camera is relying on a mechanical shutter. It is merely noted as "shutter-speed"
    when mentioned in relation to P&S cameras. Some do have mechanical shutters,
    concentric with the light-path away from the focal-plane, and are not plagued by
    this horrendous subject-distorting problem of curtain-style focal-plane
    shutters. Some only have electronic shutters. But in most every case there is
    some kind of mechanism to protect the sensor from exposure to bright lights when
    not in use.

    Why everyone went-off on what kind of shutter a P&S camera uses or does not use
    is a mystery to me. I guess if they distract themselves from and don't think
    about this subject-distorting problem inherent in every dSLR it'll make it go

    Just imagine, all those millions perhaps billions of photos taken and displayed
    so proudly for the last so-many years with dSLRs .... each and every one of them
    most likely contains distorted subjects to one degree or another. Even if the
    subject is moving slow the moving portions exposed while the shutter is opening
    and closing will still contain some distortion. The viewer not realizing this
    just accepts that distorted view of reality as normal. In fact, one reply here
    even claimed how proud they were of accepting a distorted view of reality as

    How sad that is.

    dSLR = recording a distorted view of reality

    There's no way to refute that, try as you might. The only way you will ever
    accurately capture a moving subject with a dSLR is by using a high-powered flash
    and f/stops so small as to extinguish all ambient light from your intended
    image. I don't see many people doing that. That relegates the dSLR only good for
    indoor party photos taken in dimly lit rooms or art studies arranged in
    still-life poses. I'll pass on that photography-crippling limitation thank-you.
    SelfImporantName, Jul 8, 2007
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