Mirror slap an issue?

Discussion in 'Medium Format' started by eric_m|4, Apr 14, 2021.

  1. Hi guys,

    I've heard/read several people say that vibration from mirror slaps on old, robust bulldozer cameras like Bronica S2's and Kowa 6 are so brutal that they can negatively affect the result of image as far as lack of sharpness/motion blur is concerned. I know the mirror slap is loud but is the powerful vibration an exaggeration or is it really a problem? Would this still be an issue if used on a good tripod?
     
  2. It will only be an issue when used on a good tripod. Handholding has a far greater effect than mirror slap.

    Mirror slap is often mentioned, and i suppose that there is some truth to it. But even though demonstrable under test conditions, the question really is how big an issue it is. It has not lessened people's satisfaction with the cameras they use, going by the long periods these were produced and sold without adressing the issue. Insignificant enough not to worry about at all, i'd say.
    But having said that, when possible, it doesn't hurt to prerelease the mirror.
     
  3. That mechanical clatter is post-exposure. The old mechanical beasts like Pentax 6x7s and focal plane shutter Bronicas never gave me grief. That their mirrors sounded like an old screen door slamming didn't, as q.g. observed, affect their function.
     
  4. There were a series of tests in the old enthusiasts' magazines. While I can't lay my hands on any scans of them right now, my recollection was that q.g. has the right of it
    .
    Here is a column from the incomparable Burt Keppler about the broader problems of camera vibration:
    Keppler-vibration,-misc-1985-01-MP-vibration.jpg
    Modern Photography 1985-01
    • Obviously, it's about small format, but the general lessons are as much or more true for larger formats. On the other hand, the fact that less enlargement is needed for a larger negative, helps the other way.
     
  5. Hasselblad mirror slap is definitely an issue when used on a tripod. With film, it might cause a noticeable blurring, but with a digital back you usually see doubling at the pixel level. I make it a practice to raise the mirror whenever possible, e.g., for landscapes. Even a focal plane shutter can show vibration in the image, which is why I seldom use it for fussy work.
     
    andyfalsetta likes this.
  6. No, it's when the mirror swings up and comes to a sudden stop immediately before the exposure. Not post-exposure.

    The amount of blur also depends, not only on the magnitude, but on shutterspeed, i.e. the duration of the vibration relative to the duration of the exposure. At long shutterspeeds, it wil not be noticable at all.
    Another factor is the relative mass and speed of the moving part, compared to the mass of the camera it should set in motion.
    And how well dampened the mirror is.

    But it is indeed not something to worry about.
     
  7. What vibration the camera "feels" and you hear as mirror clatter aren't necessarily the same. Massive, all-metal cameras like the old Bronicas and Pentax 6x7(no experience with Hasselblad) did, as Keppler noted, dampened vibration rather well. Neither camera ever produced any blurring I could attribute to mirror slap. Any blown shots were my fault alone.
     
  8. If you don't see camera shake from the mirror, you aren't looking close enough, or other issues prevail, including focus and limitations of the medium.
     
    andyfalsetta likes this.
  9. Or there is nothing there to see, of course.
     
  10. Sandy Vongries

    Sandy Vongries Administrator Staff Member

    I have been using SLRs and DSLRs for 50 years and change. Just last week, got a pair of quite a decent images at 1/5 and 1/6 hand held. There is no doubt in my mind that at some arcane, far borders of photography the issue may impact outcomes, but I have never encountered it. Just call me "Slap Happy".
     
  11. When shooting close ups (on a tripod) like minimum focus on the 80mm on my 500c or when using an extension tube, the vibration is real and although the average viewer may not see it, you don't have to be critical to see its impact - especially with digital. I have made a habit of pre-releasing the mirror for this reason.
     
    Ed_Ingold likes this.
  12. Owning a few Kowa 6s and previously an S2 , I'd say that the Kowa is whisper compared to the clatter of an S2 ;). Peter
     
    rodeo_joe|1 likes this.
  13. Yup, and Natty Bumppo could shoot the eye of a grasshopper at 50 yards. (Of course, Mark Twain remarked in his scathing review of James Fenimore Cooper, "If you can't see it, you can't shoot it.")

    Not all photos need maximum resolution, including those situations where 1/5 second is all you can get. I have achieve surprisingly good results at 1/15 with a 300 mm lens, with the aid of in-body image stabilization and a convent door frame for support.

    Digital imaging is a whole other ball game for medium format. The acuity is high enough, even in my 16 MP sensor, to detect the camera shake of the flapping mirror in an Hasselblad. Even with the advantage of electronic shutters and solid tripods, getting pixel-sharp results at 40-60 MP takes extra care.
     
    andyfalsetta likes this.
  14. So those SLR manufacturers that fit an MU (Mirror-Up) facility were just wasting their time designing it? And everyone using MU is wasting their time using it?

    I don't think so.

    Fit a really long lens on a less than rock-steady tripod (i.e. any tripod you can easily carry more than 500 yards) and watch the image dance at the slightest touch of a tripod leg. Then tell me mirror-slap will make no difference?
     
    andyfalsetta and Ed_Ingold like this.
  15. But when most shoot 80-150mm lenses? Not so much. As Herb Keppler noted, it's shutter speed dependent.
     
  16. One tends to expect more from medium format than from a cell phone, or even a small format camera. Use of a 500 mm lens was simply an example which makes visible how easily even a solid tripod can be disturbed. The effect of mirror vibration on a "normal" MF lens (60-110) is easily visible in a digital image. For landscapes, I would not only raise the mirror, but use a soft release. My favorite Hasselblad was an ELD555, which has an electronic cable release (and uses a CFV digital back without a sync cable).

    The 1/F rule for acceptably sharp handheld photos is actually closer to 1/3F before camera shake is nearly invisible. In practice, that limits you to 1/250 or faster, which is not always easy to achieve with slow MF lenses.
     
  17. The 1/F rule for acceptably sharp handheld photos is actually closer to 1/3F before camera shake is nearly invisible. In practice, that limits you to 1/250 or faster, which is not always easy to achieve with slow MF lenses.

    And that's why God created tripods...Enough tedium already.
     
  18. ... and gave us enough sense to recognise that mounting a heavy rig out of balance on a too flimsy tripod is not the thing to do.

    I will join the mood and change my initial reply to "it is an issue when it is an issue".
     
  19. Bad_Tripod_combination.JPG

    When mirror shock is an issue.

    (It's a Carl Zeiss tripod, so it must be good...)
     
    peter_fowler and andyfalsetta like this.
  20. Hilarious! That Fuji pre-loads that wispy tripod so much it wouldn't dare quiver!
     

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