this video should help explain things about shutter speeds

Discussion in 'Open Discussion' started by pellicle, Feb 2, 2015.

  1. pellicle

    pellicle Mu-43 All-Pro

    Feb 10, 2010
    Southport, OzTrailEYa
    pellicle
    Hi

    https://www.youtube.com/watch?v=CmjeCchGRQo

    its a slow motion of a 7D (found it elsewhere) and shows the moving slit of higher speeds quite clearly. I think it also demonstrates well to folks why flash sync speeds are what they are and why...

    :)
     
    • Like Like x 3
  2. wjiang

    wjiang Mu-43 Hall of Famer

    And why higher spec'd shutters are expensive and over time malfunction (e.g. older E-M5s at high shutter speeds).
     
  3. OzRay

    OzRay Mu-43 Legend

    Jan 29, 2010
    South Gippsland, Australia
    Ray, not Oz
    That's why iris shutters rule in flash photography. ;)
     
  4. pellicle

    pellicle Mu-43 All-Pro

    Feb 10, 2010
    Southport, OzTrailEYa
    pellicle
    aren't they sort of limited to 500th anyway? (ponders that my EOS 620 was 250th back in 1989)

    ps: quick google shows some high spec leaf shutters go quite high ... sadly none of mine (which are all on LF cameras anyway ... so its a bit moot)
     
  5. OzRay

    OzRay Mu-43 Legend

    Jan 29, 2010
    South Gippsland, Australia
    Ray, not Oz
    Yes they are, but as far as I'm aware, there has never been an SLR shutter that has had a flash sync speed anywhere near that. The 1/320 sec of the E-M1 is one of the highest usually available.
     
  6. wjiang

    wjiang Mu-43 Hall of Famer

    I think many of the LX series (e.g. LX100) sync at 1/2000s :-O
     
  7. OzRay

    OzRay Mu-43 Legend

    Jan 29, 2010
    South Gippsland, Australia
    Ray, not Oz
    Them's not SLRs. ;)-
     
  8. wjiang

    wjiang Mu-43 Hall of Famer

    It's way easier to do leaf shutters when you don't have interchangeable lenses I would imagine.
     
  9. OzRay

    OzRay Mu-43 Legend

    Jan 29, 2010
    South Gippsland, Australia
    Ray, not Oz
    Leaf (iris) shutters allow much higher sync speeds and the smaller they are, the higher the shutter speeds possible. And you could possibly incorporate two shutters, one to open and the other to close.
     
  10. jyc860923

    jyc860923 Mu-43 Hall of Famer

    Feb 28, 2012
    Shenyang, China
    贾一川
    Nikon D70 could do that, 1/500s

    but why don't they do that with new cameras? expensive and malfunction?
     
  11. OzRay

    OzRay Mu-43 Legend

    Jan 29, 2010
    South Gippsland, Australia
    Ray, not Oz
    The D70 has a hybrid mechanical/electronic shutter, so it's somewhat different from the run of the mill SLRs, but why it no longer exists is anyone's guess.
     
  12. Vivalo

    Vivalo Olympus Loser

    941
    Nov 16, 2010
    Finland
    I think it's CCD vs CMOS thing...
     
  13. jyc860923

    jyc860923 Mu-43 Hall of Famer

    Feb 28, 2012
    Shenyang, China
    贾一川
    that explains it, thanks:thumbup:
     
  14. jyc860923

    jyc860923 Mu-43 Hall of Famer

    Feb 28, 2012
    Shenyang, China
    贾一川
    I had a Panasonic P&S back in 2011 with CCD sensor, according to the manual when shooting fast moving subject, there will be rolling shutter distortions but from my experience there never was any sign of rolling shutter, of course that P&S doesn't have mechanical rolling shutter, but if it's P&S with CMOS sensors you can clearly find the evidence of rolling shutter.
     
  15. pellicle

    pellicle Mu-43 All-Pro

    Feb 10, 2010
    Southport, OzTrailEYa
    pellicle
    How so?
     
  16. wjiang

    wjiang Mu-43 Hall of Famer

    CCDs usually have global shutter, while CMOS typically have rolling shutter. It's just easier and more cost effective to make them that way.

    CCD sensors are just charge buckets, with large photo sites that don't need much circuitry behind them. All the amplification and read circuitry is at the output stage rather than at the photo sites, and they read pretty much sequentially like a shift register. Global shutter is no big deal as it's a function of the photo sites rather than the output circuitry in this case.

    CMOS sensors on the other hand, have amplifiers and read circuitry behind each photo site. To drive all the output stages at all photo sites at once would require a huge parallel bus, high power consumption, and result in a giant processing load and heat to deal with. To get around this a CMOS sensor is usually read and driven in a rolling fashion. You can find CMOS sensors with global shutter, but they tend to be in really expensive and chunky (for power, processor and heat reasons) video devices.
     
    • Like Like x 2
  17. OzRay

    OzRay Mu-43 Legend

    Jan 29, 2010
    South Gippsland, Australia
    Ray, not Oz
    From what I understand, global shutters are a very recent development and still don't appear in many cameras. The likes of the E1 had a very standard shutter mechanism.
     
  18. wjiang

    wjiang Mu-43 Hall of Famer

    I meant electronic global shutter btw, which aren't that new with CCDs. Video cameras don't use mechanical shutters...
     
  19. OzRay

    OzRay Mu-43 Legend

    Jan 29, 2010
    South Gippsland, Australia
    Ray, not Oz
    Reading about how global shutters work; http://www.red.com/learn/red-101/global-rolling-shutter, I'm not so sure that it's quite that simple.
     
  20. G3user

    G3user Mu-43 Regular

    66
    Nov 26, 2013
    UK
    Cool! Thanks for posting. I was surprised by how much vibration there is of the mirror and the shutter (when it reaches the bottom). I wonder how fast these things are moving?!