Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 71,908   Posts: 1,584,651   Online: 852
      
Page 2 of 2 FirstFirst 12
Results 11 to 19 of 19
  1. #11
    MattKing's Avatar
    Join Date
    Apr 2005
    Location
    Delta, British Columbia, Canada
    Shooter
    Multi Format
    Posts
    12,945
    Images
    60
    I think Q.G. would be more correct if instead of referring to "reflecting surfaces" he referred to beam splitters or other systems that reflect part of the light and transmit the rest.
    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

  2. #12
    Sirius Glass's Avatar
    Join Date
    Jan 2007
    Location
    Southern California
    Shooter
    Multi Format
    Posts
    13,924
    Some auto focus slrs use beam splitters. Those cameras need circular polarizors, the rest, including Hasselblad, do not.

    Steve
    Warning!! Handling a Hasselblad can be harmful to your financial well being!

    Nothing beats a great piece of glass!

    I leave the digital work for the urologists and proctologists.

  3. #13
    MattKing's Avatar
    Join Date
    Apr 2005
    Location
    Delta, British Columbia, Canada
    Shooter
    Multi Format
    Posts
    12,945
    Images
    60
    The New Canon F1 is an example of a manual focus camera that uses beam splitters in its metering system. There are others. You need to use circular polarizers with them.

    I think (but cannot find any confirmation for this) that the Canon AE1 was another.

    EDIT: A Leicaflex SL is another example of a manual focus camera that uses beam splitters in its metering system and therefore requires a circular polarizer.
    Last edited by MattKing; 10-31-2010 at 12:15 AM. Click to view previous post history.
    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

  4. #14

    Join Date
    Nov 2005
    Shooter
    Multi Format
    Posts
    73
    An easy way to check if a polarizer is linear or circular is to look through it and rotate it, first in the normal position and then in a reversed position. A linear polarizer will give the same effect both ways, circular polarizers only work one way.

  5. #15

    Join Date
    Jul 2009
    Location
    Hong Kong/Paris
    Shooter
    35mm RF
    Posts
    150
    Thanks for all the info & sorry for taking the thread off topic!

  6. #16

    Join Date
    Jul 2007
    Location
    Netherlands
    Shooter
    Medium Format
    Posts
    5,686
    Quote Originally Posted by JLP View Post
    I stand corrected then.
    Will the mirror then not be a reflecting surface?
    Yes.
    And some cameras, or rather their metering systems, may have a problem with that.

    "May", because having a reflecting surface (mirror, secondary mirror behind a semi-transparant spot in the main mirror, semi-silvered surface in a beam splitter prism, etc.) does not automatically mean it is sensitive to the direction of polarisation.

  7. #17

    Join Date
    Jul 2007
    Location
    Netherlands
    Shooter
    Medium Format
    Posts
    5,686
    Quote Originally Posted by MattKing View Post
    I think Q.G. would be more correct if instead of referring to "reflecting surfaces" he referred to beam splitters or other systems that reflect part of the light and transmit the rest.
    Not reflecting all of the light is not a condition for (possibly) being senstive to polarisation.
    The thing to worry about in beam splitters too is the reflecting part. That it passes on some of the light is not relevant, unless that light is used for the metering systems (i.e. the light used for the metering systems is not reflected).

    So i would be more correct if i would refer to reflecting surfaces. And so i did.

  8. #18
    benjiboy's Avatar
    Join Date
    Apr 2005
    Location
    U.K.
    Shooter
    Multi Format
    Posts
    7,208
    Quote Originally Posted by JLP View Post
    I stand corrected then.
    Will the mirror then not be a reflecting surface?
    Hi Jan, The mirrors on cameras that require circular polarizers have portions that are indeed transparant to allow light through, and the polarized light that enteres the camera not only effects the exposure but the auto focus mechanism also on most modern SLRs.
    Ben

  9. #19

    Join Date
    Jul 2007
    Location
    Netherlands
    Shooter
    Medium Format
    Posts
    5,686
    Again, it's not the semi-transparancy of beam splitters or mirrors that could be an issue. It's the reflecting thing they do.

    If an AF or metering system is located in the prism housing, i.e. after the mirror, they could have poblems with polarised light.

Page 2 of 2 FirstFirst 12


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



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