Mirror lock up and when?

Discussion in 'Medium Format' started by jim_gardner|4, Jan 30, 2021.

  1. When I first learned about mirror lock-up it was for certain fish-eye lenses
    that stick too far back.
    q.g._de_bakker likes this.
  2. Of course, you can't view the scene through the lens and require a separate viewfinder that attaches to the camera to look through. With "normal" lenses, you look through the lens, then lock up the mirror to reduce vibrations, and then release the shutter separately.
  3. This eventually became the issue that popularized awareness of (as opposed to more common reasons to use) the mirror lockup feature, after Nikon made fisheye lenses mainstream in the '60s. But originally the Nikon F included MLU mainly to accommodate Nikon's first "superwide" lens, the 2.1cm f/4 Nikkor-O: a symmetrical wide designed for RF concurrently offered with the F mount. A very interesting lens, which like all of Nikon's later 20mm iterations has a unique combination of pictorial qualities. Each succeeding generation of 20mm Nikkor re-juggled performance specs: no two are alike, each will suit some types of photography better than others. See MIR page on the 2.1cm for lots of details (scroll to the end for a photo of the nifty rear lens cap that includes a mount for the external F viewfinder).

    Zeiss actually beat Nikon to the punch with a mirror-lockup-required symmetrical 20mm Biogon for their Contarex SLR. But only a few of those lenses were made and hardly anyone bought a Contarex, so Nikon F is more commonly remembered as "the" SLR that needed MLU for an early superwide and later fisheyes.
    Last edited: Feb 7, 2021
  4. Looking at Wildi, I see that setting the ELD to the SR mode, "the camera returns to the pre-released state after the picture cycle," eg, the mirror returns to its mirror up position. Correct?
  5. As I couldn't afford the Nikon fisheye, I now have a Lomography Fisheye1.


    Not only does it not have a fisheye viewfinder, but the viewfinder that it does
    have is half blocked by the lens. It seems that the fisheye2 has a better one.

    As well as I know, the MLU needing Nikon fisheyes don't work with newer cameras,
    even though they have MLU.
  6. Correct that this is in all editions of Wildi's manual.
    And it is a correct description of SR (or RS) setting: the mirror is prereleased immediately after winding on, so goes up, comes down again and goes up again.
    What is incorrect in all editions of Wildi (they all show the same diagram) is that in AS setting the mirror would stay up as long as the sequence of exposures lasts. it does not. The mirror in no EL(...) model actually stays up.
    Last edited: Feb 7, 2021
  7. There has to be a youTube video that demonstrates the Hasselblad EL, ELM or ELX pre-release mode, either intentionally or as part of a related demo, if one could just think of the correct search terms to pull it up. The action of "continuous pre-release mode" in motorized Hasselblad V cameras is something that has to be seen to be understood. Words can't convey it clearly because logic balks: it doesn't operate as one would expect a motorized "lockup" to work.

    For those unfamiliar, the Hasselblad V firing/winding mechanical sequence didn't permit deactivating the mirror altogether because the mirror flipping up and down could not be completely decoupled from the rest of the cycle. The cycle could only be "paused" with the mirror in up position right before the final step of the lens leaf shutter firing, after which the mirror must come down to complete the film advance, body cocking and lens shutter cocking sequence (Mamiya RB67 works the same way).

    In practical use it doesn't matter that the mirror cycles instead of remaining fully locked up: EL bodies are heavy, and a remote cord allows hands-off firing/winding/mirror action. Set the motor dial to SR mode, and a EL series 'blad will immediately close the lens leaf shutter, stop the lens down to shooting aperture, flip the mirror up, and open its rear auxiliary shutter. Wait a second or two if you're concerned about those little vibrations. Then, pressing the shutter release (or remote button) will fire just the lens leaf shutter to make the exposure (like a TLR).

    Once the lens shutter closes, the EL will advance the film to next frame and cycle/cock the mechanism for the next "pre-released" shot: aux shutter closes, mirror comes down, lens shutter and aperture open wide, then everything instantly pre-releases once again (lens shutter and aperture close, mirror flips up, aux shutter opens and the camera waits for you to trigger just the leaf shutter). It takes longer to read this than for the camera cycle thru film advance/pre-release, barely a second from one frame shot to being ready for the next. Vibration is effectively minimized as much as full time MLU on other cameras.

    Theoretically you could argue the mirror always flipping back before locking up again for each "MLU" shot prevents using fisheye or symmetrical wides, but Hasselblad neatly sidestepped mirror issues with its lens offerings: retrofocus 30mm full-frame fisheye and 40mm superwide for reflex viewing, plus the superb symmetrical 38mm Biogon ultrawide mounted permanently to its own dedicated non-reflex "SWC" body.
    Last edited: Feb 7, 2021
  8. You're right, Orsetto, that the mirror is not disengaged in any of the EL-models. You're wrong in suggesting that this could not have been done. It could have been done easily. But they just haven't.

    If the ELDs (or any other model) would have offered lock up, We could perhaps have seen a version of the 60 mm Biogon for use by other people than astronauts and photogrammetrists. As it is, we would have to buy a mirrorless photogrammetry Hasselblad. Or use a 2000-series camera.
    We might have seen other speciallity applications as well.
  9. If it was just a case of them preferring not to do it that way, then its entirely possible they did make a handful of custom examples with full-time lockup option for select photographers. Considering some of the oddball customized bodies and backs featured in Nordin's "Compendium"and seen on auction sites, Haselblad was apparently willing to do whatever its favored photographers asked. Tho I can only imagine the cost back in the day for specials like the "SWC-EL" etc.
  10. Custom jobs. For people with huge amounts of money?
    I think quite a few of those odd jobs were the results of ideas the people at Hasselblad tinkered with. In their spare time, or maybe as part of their jobs. Doodlings. Not many as a result of customer request.
    And there are not that many custom adaptations, really.
    The stuff you see on auction sites made its way there when Hasselblad dumped their inventory.

    Except, of course, those thinges made for NASA. They have deep pockets.
    NASA started customizing Hasselblad cameras themselves, before involving Hasselblad. They also asked Franke & Heidecke (Rollei) wether they would like to make cameras for NASA. They declined.
    I don't know that Hasselblad made any money working for NASA. Huge amount of publicity though.

    But anyway, an EL-model with mirror lock up has not been seen yet. And we will never see one, unless someone tries to customize one at home.
    It is highly unlikely that they did make some, just because, and then offer them to 'select photographers'. Or rather: it did not happen.
  11. Re-read my post: that is is not what I wrote. I did not suggest Hasselblad randomly made a few full-lockup EL cameras "just because" and then offered them to random photographers. I simply noted they were known for occasionally making "specials" at the request of commercial, government or art photographers they were interested in supporting with special projects. Neither of us can truly say for certain full-time lockup on an EL body was even possible at all, or if so whether a couple of custom ELs may have been special-ordered with the feature. If any were made, there'd likely be no external evidence (it would a modification of the existing pre-release function) and nobody would be aware of it except that photographer.

    But I don't think any were ever made, because I don't think they could be made: the clean-sheet 2000 series focal plane shuttered electronic 'blads had already offered full lockup for two decades before the final 555ELD debuted in 1998, yet that final EL variant (containing several bespoke factory-installed mirror modifications) still did not offer full time lockup. Full time lockup would have certainly been welcomed by the 555ELD target market of digital studio pros, so the ELD's lack of that feature indicates Hasselblad considered it unacceptably problematic to implement in any of the leaf-shutter-only bodies. Given the fact full time lockup was again omitted from their most advanced 200-series electronic metered models like 203fe, it is not unreasonable to conclude Hasselblad considered pre-release less complex to incorporate. For whatever technical reason, the 2000 series mechanism was apparently more amenable to full time lockup, so they remain the only V 'blads with both user-selectable pre-release and full-time MLU options.
    Last edited: Feb 8, 2021
  12. A lot of speculation again, orsetto, mixed with some flawed conclusions.
    But let us not waste more time on such.
  13. We've been down this road before, you and I. This is a discussion forum, not Hasselblad's own corporate site. Reasonable "speculation" and conclusions based on our personal experience with various cameras and their overall histories is perfectly natural in such discussions, as is use of common terms that may not be scientifically accurate but are practical conventions in photographic equipment discussions. No one here could possibly misinterpret my posts as anything but personal experience and opinions, nor would they assume I'm speaking directly for mfrs, nor do I ever claim to be. We only "waste time" when you spuriously prosecute and we posters needlessly defend what was perfectly obvious to begin with (that our opinions, experiences and conclusions are our own).

    Flagging absolute factual errors (i.e. if someone claimed the 500cm has "full time mirror lockup") for correction is of course a different matter. We all do that from time to time.
    Last edited: Feb 8, 2021
  14. Yes, our paths have crossed before. That is: you were caught telling nonsense before.
    It is BS to talk about "Hasselblad's own corporate site". But if you think it not so, why still speculate?
    Reasonable speculation has no place where knowledge is available. Just that you like to speculate is not enough reason to put up with that. It is not of equal value, if of any value at all.
    And what was reasonable about your speculations above? You "don't think" that any were, "because" you "do not think they could", "yet...". What you mean is you do not know. Not about what they did. Not about what they could. Not about what yet they might have done. Et cetera.
    Reasonable speculation might be wanted when knowledge does not exist. But then we indeed need reasonable speculation, based on an understanding of how things work, so also of how they could have been.

    And there we are, wasting yet more time on this nonsense... Just leave it be.
  15. The SR mode on the ELD is all I would ever need.
  16. Unfortunately the early focal plane shutter Hasselblads (Series One, 1600F, and 1000F) also don't have benefit of a mirror pre-release function. Aside from the differences in shutter between the 1000F and 500C, mirror prerelease and a self timer were two of many innovations the 500C offered for those who wanted to "jump ship" from their focal plane Hasselblads.
  17. Please note, though, that beginning with the 500 ELX, no EL-model offers SR-mode. Only the EL and EL/M did.

    The rest, including your ELD, offer RS-mode instead.
  18. The mirror action in a 555ELD is very soft in the "locked" modem with no slap to disturb the camera significantly. All this meaningless discourse ignores the initial premise - when and where to use mirror pre-release? The answer is simple - any time you need maximum sharpness.
    andyfalsetta likes this.
  19. Sure.
    And your meaningful contribution was to say something that was not quite true, wasn't it? So you now chide the discourse you injected that into as meaningless. Kudos!

    The mirror slap in the ELD's RS or AS mode is no different from that in any other mode. So, if i understand you correctly, you are saying that we do not need any prerelease on the ELD at all. Just O and A modes, single and continuous.
    But you're not, since you found "a noticeable loss of sharpness". So what do you mean, "with no slap to disturb the camera significantly"?
    Last edited: Feb 9, 2021
  20. Yes, keep up pouring on the sanctimonious snark, q.g. because that wins people over so well.

    For the love of Victor H, the only reason you and I get derailed is because you have different rules for yourself and everyone else. You jump on my or others perfectly reasonable observations with a dismissive "show me signed notarized engineering documents or your comment has zero merit" routine, which affords you the appearance of seeming very concise because any response will tend to drag on with explanations, which you then dismiss again, and the cycle repeats.

    I observed that Hasselblad did not include full MLU in any leaf-shutter-only motorized or crank wound body, drawing the reasonable inference that perhaps Hasselblad felt pre-release was less complex given the already very elaborate mechanical ballet for making a normal exposure. Nothing controversial there at all.

    Your response was a dismissive "You're wrong in suggesting that this could not have been done. It could have been done easily. But they just haven't."

    So, I'm not allowed to speculate it was "not thought to be the optimal way to implement mirror control in the non-focal-plane bodies", but you can definitively rebut "you're wrong, it could have been done, they just chose not to"? How is your statement not equally speculative? Neither of us is privy to the engineer's actual reasons. We can only observe that full MLU was installed only in the unmetered 2000 series focal plane shutter models, not before and not after. It is natural to wonder why, and theorize perhaps after trying full MLU in the 2000s the original pre-release was considered a better fit for these cameras by the mfr, so the later 501cm/cw and 555ELD remained with pre-release.

    Foolishly, I answered your "it could have been done" with "then who knows, perhaps they did a few on special order, given the custom specials they sometimes produced" which merely engendered more dismissive snark in return. Agree, disagree, agree to disagree: no form of engagement resolves anything. Got it: next time you tear apart an innocent observation, I'll defer to your making absolutely certain no reader use their own judgement in parsing it.

Share This Page