Can you use mirror lock-up on RZ II when doing time exposures?

Discussion in 'Medium Format Cameras and Accessories' started by Holly, Aug 7, 2010.

  1. Holly

    Holly Member

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    ...Or will the shutter just close after 55 seconds?
    I can't seem to decipher from my RZ manual how to use a cable release, mirror lock-up, and a 10 minute exposure all at the same time.
    Help!
    Thanks.
     
  2. Steve Smith

    Steve Smith Subscriber

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    I don't know the answer but mirror lock up will be of little or no benefit with a ten minute exposure.


    Steve.
     
  3. Darkroom317

    Darkroom317 Member

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    I've done exposures from 4 to 15 minutes with my RB67. Mirror lock-up wasn't necessary.
     
  4. Rudeofus

    Rudeofus Subscriber

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    Think of it like this: you go through all this effort, you use a cable release and get your mirror to be up before the shutter opens ... and then, when you think the exposure is done and while the shutter is still open you have to grab the damned lens and have to manually shift the switch from T to N position to close the shutter. Believe me, of all the things the RZ67 is near perfect for, and there are many of them, long term exposure is not one of them. If shake free long term exposures are a must (e.g. you have a bright point light source in the frame), either pick another camera or use a gobo to cover the lens as a substitute for the shutter.
     
  5. tac

    tac Member

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    I constructed an 8 inch by 8 inch piece of cardboard covered with black velveteen to use as a "shutter" while working the mechanism on my RZ for long exposures, as previously noted.
     
  6. 2F/2F

    2F/2F Member

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    I place the lens cap on front if not using a hood (In overcast weather or other low light I sometimes don't bother.), or my hand, a notebook, a 4x5 film box, etc. over the lens if I am using a hood. In a ten minute exposure, the time it takes to do that is a small fraction of the exposure, so while it is technically exposed onto the film, it does not show up in the picture.
     
  7. Holly

    Holly Member

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    Aha! Fake shutter, genius. Why didn't I think a that.
    Reason I want mirror lockup is because the shot I want would be at night, with passing figures and
    traffic but also with fixed structures like roads/buildings which need to be as sharp as humanly possible,
    with as big a depth of field as poss. So I want to try to get the smallest ap I can. Figured that my
    issues in the past of doing the f32+ apertures during the day, and not using MLU, and getting the perfect
    shot *apart from the bloody camera tremor* meant it was necessary to use MLU at any time of day or
    night.
    But then, whoever pointed that out about manually moving the dial from T to N, you're right, it's going to
    give a little shake at that point anyway! Hmmmmm. There doesn't seem to be a way to keep everything
    super-sharp other than putting a
    black screen of some sort in front of the lens at the end of the time exp. and THEN moving the T/N dial.
     
  8. lxdude

    lxdude Member

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    If you're worried about mirror vibration at the beginning of the exposure, hold something over the lens before you trip the shutter and remove it a few seconds after tripping it, then start timing.

    BTW, the cover the lens technique predates mechanical shutters. A hat was commonly used to time the exposure back in ye olden days when all exposures were long.
     
  9. Rudeofus

    Rudeofus Subscriber

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    Two more things to consider: first, if you use tiny apertures, diffraction is going to kill your sharpness. See here for details, replace grain size for pixel size to make it applicable to film photography. To make a long story short: you can't have infinite DOF and sharpness at the same time.

    Second: I wouldn't worry about 3 seconds of camera shake in a 10 minute exposure. Just do the math how those 3 seconds register in the frame, they're only 1/200 of the total exposure, which is 7-8 stops below! The only time camera shake matters is, as I wrote above, if you have bright static point light sources in the picture.
     
  10. Steve Smith

    Steve Smith Subscriber

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    Camera shake is at it's most noticeable when the shutter speed is the same duration as the shake lasts for. As you increase the time the shutter is open for, the fraction of the camera shake time compared to the total exposure time gets smaller and therefore less noticeable.

    For a ten minute exposure, even using the silly shutter closing method Mamiya (and Bronica) use on their lenses will not show any reduction in sharpness on the final image. The black cloth/black board/lens cap/hat covering method is a good one though especially for exposures of a few seconds.


    Steve.
     
  11. 2F/2F

    2F/2F Member

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    You must mean that you can't have extremely wide DOF and maximum sharpness at the same time. You can most certainly have sharpness with wide DOF.

    IMHO, there are many cases (in fact, almost every case in which deep DOF is desired) in which having deep DOF trumps having the maximum sharpness from ones lens. The sharpness that my lens can render being blunted by diffraction is one of the least of my worries when shooting. As long as I know that my lens is inherently a sharp lens, I know that it will be "good enough" for me at any aperture, and that DOF is a far more important aesthetic "worry."

    With a camera that allows you to orient the plane of critical focus, you can most certainly have extensive front to back focus in an image, and maximum sharpness (or close to it) from ones lens.

    Here is the online article on the matter that I like best: http://www.kenrockwell.com/tech/focus.htm.
     
    Last edited by a moderator: Aug 8, 2010
  12. Holly

    Holly Member

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    So:
    I will give this all a test run on polaroid soon, but is the general consensus here that there's no
    point in using MLU, and I may as well just press the shutter button with a black thing over lens,
    then drop it away, and put it back over just before I switch T-N at the end?
    All I want is like....an insane amount of sharpness in the final image. Given that it's at night,
    and there will be fixed points of light in it, if I follow those steps the shake will be so minimal as not to
    matter?
    Thanks for all the technical support guys
    I'll give it all a whirl.
     
  13. 2F/2F

    2F/2F Member

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    For what you want, I would use Fuji Neopan 100 Acros or Kodak T-Max 100. Not only are they sharp as all get out, but they are very easy with which to figure long exposures, due to their excellent maintenance of reciprocity. With many other films, you'd have to do a fair amount of experimentation to find out how they behave in long exposures, and you would also have to spend a lot more of your precious time twiddling your thumbs waiting for the film to expose.

    If I wanted what you wanted, I would also probably use T-max developer to push the outstanding sharpness of the film to the max. There is nothing quite like T-Max film in T-Max developer. It gives a unique (though definitely "modern") look IMHO. It really does the film justice.
     
  14. Steve Smith

    Steve Smith Subscriber

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    That will work fine but even that is not essential for the ten minute exposure as you mentioned in your original post.

    For exposures like this, I would be more worried about the sturdiness of the tripod and and road induced vibration causing movement than looking to the mirror for the problem.


    Steve.
     
  15. lxdude

    lxdude Member

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    ^^Exactly^^
     
  16. Holly

    Holly Member

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    Hmm, going to be shooting in colour though...any suggestions for suitable film in colour? I'm thinking of
    a tungsten slide of some sort, but usually use Fuji 160C.
    I am slightly lazy when it comes to figuring out reciprocity and things like that..is this something I'd need
    to be hyper aware of with long night exposures?
     
  17. Holly

    Holly Member

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    So just point and fire you think? And make sure I bolt the tripod down pretty good?

    I'm just thinking that that big old mirror will go clunk and kill the shot, so I'll probably be doing the
    black-cover-up trick anyway, but I don't have a fabulously new and sturdy tripod so you're right, if anything
    is going to make the image sharper it's the tripod situation. I will take sandbags.

    I'm hoping to shoot at a time when there is not a lot of traffic or vibration around, if it's not too
    cold, so that might not be a big problem.
     
  18. MattKing

    MattKing Subscriber

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    Just thought I'd mention - with the new display settings since the APUG upgrade, some thread titles don't display fully (they are truncated) on my monitor.

    This one is kind of entertaining:

    "Can you use mirror lock-up on RZ II when doing time"

    :smile:
     
  19. Steve Smith

    Steve Smith Subscriber

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    For a long exposure the mirror movement not going to make any noticeable difference.

    Wind may also cause the camera to vibrate if the tripod is not sturdy enough. Sometimes a heavy weight hung from the centre column can help.


    Steve.
     
  20. 2F/2F

    2F/2F Member

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    If you can get a hold of some Kodak Portra 100T or Fuji NPL (both color negative films), I'd try that. If not, Fuji T64 or Kodak 64T (both transparency films).

    All four of these films are discontinued; the two transparency ones more recently.

    IME, the things to be most aware of in night exposures are high contrast compositions and reciprocity failure of your film. Many night shots are very high in contrast (with lamps or windows in the picture being much, much brighter than the things they are illuminating), and you have to be careful with exposure. The four films I mentioned help with both reciprocity and color balance.
     
    Last edited by a moderator: Aug 22, 2010
  21. mawz

    mawz Member

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    No need, Provia 100F is balanced well on the blue side and shares Acros' superb reciprocity characteristics. All of those Tungsten films will be more trouble than the tungsten balance is worth due to inferior reciprocity characteristics compared to Provia 100F. And Provia is easily available.