Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 70,550   Posts: 1,544,693   Online: 871
      
Results 1 to 9 of 9
  1. #1
    Ross Chambers's Avatar
    Join Date
    Apr 2004
    Location
    Blue Mountains NSW Australia
    Shooter
    Multi Format
    Posts
    703

    Mamiya RB 67 Bellows lens hood scale

    I've been using it for quite a time, but never really figured how to correctly use the scale on the horizontal rod. It reads, as you will know:

    90 127 180
    360
    110 140 250

    Does this mean that lenses of 90-110 mm focal length require setting the white indicator dot at that point? And similarly 127-140 mm and 180-250 mm?

    It does sound a dumb question, but i tried to figure it by looking through the viewfinder and vignetting isn't so easy to spot that way.

    Thanks - Ross

  2. #2
    Ross Chambers's Avatar
    Join Date
    Apr 2004
    Location
    Blue Mountains NSW Australia
    Shooter
    Multi Format
    Posts
    703
    My formatting of the scale was tangled in transmission, the 360 mark is, of course well to the east of the 180-250 one.

    Ross

  3. #3

    Join Date
    Apr 2010
    Shooter
    35mm
    Posts
    28
    the lines correspond with the bellows extension. at the bottom of the scale there are shaded areas: 0, +0.5, +1, +1.5 etc. this will allow you to compensate the exposure depending on the lens. because the closer the focus (the longer the bellows extension) there is more dark space between lens aperture and film that needs compensation.

    dane.

  4. #4
    CGW
    CGW is offline

    Join Date
    Apr 2010
    Shooter
    Medium Format
    Posts
    2,797
    Quote Originally Posted by danegermouse View Post
    the lines correspond with the bellows extension. at the bottom of the scale there are shaded areas: 0, +0.5, +1, +1.5 etc. this will allow you to compensate the exposure depending on the lens. because the closer the focus (the longer the bellows extension) there is more dark space between lens aperture and film that needs compensation.

    dane.
    Think he's talking about bellows lens hood accessory, not the on-camera scale. You might check online for a manual.Perhaps the butkus site has one?

  5. #5
    MattKing's Avatar
    Join Date
    Apr 2005
    Location
    Delta, British Columbia, Canada
    Shooter
    Multi Format
    Posts
    12,391
    Images
    60
    Quote Originally Posted by CGW View Post
    Think he's talking about bellows lens hood accessory, not the on-camera scale. You might check online for a manual.Perhaps the butkus site has one?
    It does:

    http://www.cameramanuals.org/mamiya_...ens_hood_g.pdf

    Apparently, there is an accessory mask for the 360
    Matt

    “Photography is a complex and fluid medium, and its many factors are not applied in simple sequence. Rather, the process may be likened to the art of the juggler in keeping many balls in the air at one time!”

    Ansel Adams, from the introduction to The Negative - The New Ansel Adams Photography Series / Book 2

  6. #6
    Ross Chambers's Avatar
    Join Date
    Apr 2004
    Location
    Blue Mountains NSW Australia
    Shooter
    Multi Format
    Posts
    703
    I did look at the PDF manual, it doesn't really elucidate on the markings on the scale.

    For a while I suspected that the duplicated numbers, one above and one below at the very same point, might be for different Mamiya models.

    Now I'm guessing that they represent a range of focal lengths of lenses e.g 90-110 mm, 127-140 mm, 180-250 mm, and in each setting vignetting is avoided for lenses of those lengths.

    From experience I know that the possibility of vignetting is not necessarily apparent in the viewfinder.

    Can anyone confirm this?

    Thanks - Ross

  7. #7

    Join Date
    May 2003
    Location
    Valley Stream, NY
    Shooter
    Multi Format
    Posts
    3,216
    It says, and I quote, "The numbers on the extension scale bar represent focal length of lenses." It goes on to say, and I'm paraphrasing here, that it won't vignette if you set the bellows to match the lens focal length; but it will if you extend it out too far. It's an adjustable bellows shade. How hard is it to figure this one out? I could hand this to a reasonably curious and intelligent 10 year old and he'd have it figured out in 5 minutes.
    Frank Schifano

  8. #8
    MattKing's Avatar
    Join Date
    Apr 2005
    Location
    Delta, British Columbia, Canada
    Shooter
    Multi Format
    Posts
    12,391
    Images
    60
    I expect that the difficulty here is that OP's bellows has more focal length numbers on it than are shown in the butkus manual.
    Matt

    “Photography is a complex and fluid medium, and its many factors are not applied in simple sequence. Rather, the process may be likened to the art of the juggler in keeping many balls in the air at one time!”

    Ansel Adams, from the introduction to The Negative - The New Ansel Adams Photography Series / Book 2

  9. #9
    Ross Chambers's Avatar
    Join Date
    Apr 2004
    Location
    Blue Mountains NSW Australia
    Shooter
    Multi Format
    Posts
    703
    Thanks Matt, that is indeed the case, as I said "the duplicated numbers, one above and one below at the very same point," being "90-110 mm, 127-140 mm, 180-250 mm".

    I did find the PDF manual and read it before posting my original question, it did not say anything about this double set of focal lengths, that's why I had hoped to find experienced advice from this forum.

    To be frank, I guess that I'll just have to ask a passing 10 year old, he or she may have a polite and comprehending answer.

    Regards - Ross



 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



Contact Us  |  Support Us!  |  Advertise  |  Site Terms  |  Archive  —   Search  |  Mobile Device Access  |  RSS  |  Facebook  |  Linkedin