Focal Length

Discussion in 'Digital Photography' started by ghking, Feb 8, 2008.

  1. ghking macrumors regular

    ghking

    Joined:
    Jul 21, 2007
    #1
    hello
    i need to fill in boxes for 'Focal Length' and 'Focal Length Multiplier' for my camera in this panoramic stitcher Hugin. The problem is i have no idea what it is or how to find it for my camera. I have a Kodak Z812 IS 36mm with an Opteka .22x fisheye converter lens. Can anyone help me out?
     
  2. JNB macrumors 604

    JNB

    Joined:
    Oct 7, 2004
    Location:
    In a Hell predominately of my own making
    #2
    The focal length is whatever you shot it at (wide open would be the 36mm, all the way out is 432mm), and focal length multiplier is the .22X adapter. Without the adapter it would be 1.0.

    On an APS-C body there would be the lens focal length, a crop factor of 1.6X, and the fisheye of .22X.
     
  3. ChrisA macrumors G4

    Joined:
    Jan 5, 2006
    Location:
    Redondo Beach, California
    #3
    Is it realy a 36mm lens? Likely it is "equivalent to a 36mm lens on a 35mm camera".

    What the program wants is the real focal length of the lens not the "marketing focal length". This should be recorded in the data included in the JPG file. You can read this in many image viewer programs using some option like"vew camera data". The datain there will be "real". But the camera had no way to know about your .22X converter so multiply the recored FL by .22 Aw, but I see above that the program offer to save you the effort of multiplying so yo can enter (maybe) 7.0 and .22

    For your purposes if the subject was really far away any reasonable values will work.
     

Share This Page