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Widest lens for u43?

Discussion in 'Adapted Lenses' started by Ravenscroft, May 8, 2015.

  1. Ravenscroft

    Ravenscroft Mu-43 Rookie

    14
    Apr 16, 2015
    • Like Like x 2
  2. DeeJayK

    DeeJayK Mu-43 Hall of Famer

    Feb 8, 2011
    Pacific Northwest, USA
    Keith
    Here's a video review of another lens that is just a bit wider (6.5mm), but that also covers the 4K portion of the GH4 sensor (and presumably the BMPCC as well):
     
  3. tkbslc

    tkbslc Mu-43 Hall of Famer

    I'd still guess that a rectilinear de-fished 7.5mm is wider. Works out to something like a 4.5mm lens based on 130mm horizontal FOV.

    These are definitely cool finds, though, especially given the aperture.
     
  4. wjiang

    wjiang Mu-43 Hall of Famer

    The Kowa is a C-mount and doesn't quite cover a full 4:3 sensor, it's the basis for the proper m4/3 Kowa 8.5mm f/2.8 rectilinear though which is an expensive but good manual lens.
     
  5. budeny

    budeny Mu-43 All-Pro

    Mar 4, 2014
    Boulder, CO
    What profiles are you using?
    I just did a quick check and my rectilinear profile rounds to about 122 degrees and 148 degrees for stereographic projection.
     
  6. tkbslc

    tkbslc Mu-43 Hall of Famer

    The horizontal FOV does not change when de-fishing, so it is still the same 132 degrees as a regular fisheye image. (accidentally typed as mm instead of degrees above) The diagonal FOV gets changed because the corners are stretched and cropped and the aspect ratio changes. So it is a bit difficult to compare with regular wide angles.
     
  7. budeny

    budeny Mu-43 All-Pro

    Mar 4, 2014
    Boulder, CO
    Really?



     
    • Like Like x 1
  8. tkbslc

    tkbslc Mu-43 Hall of Famer

    Mine don't change FOV. Not sure how you are doing it. This is Panini General projection, but it's the same with most projection methods.

    P1130850 - P11308500000. P1130850.
     
    Last edited: May 11, 2015
  9. budeny

    budeny Mu-43 All-Pro

    Mar 4, 2014
    Boulder, CO
    Ok, I see - Hugin is not locking to 4/3 ratio, so its output is wider FOV and using diagonal FOV is not really applicable here.

     
  10. tkbslc

    tkbslc Mu-43 Hall of Famer

    Yes. Stretching the edges results in a different aspect ratio. I did make sure to mention horizontal fov for that reason.
     
  11. Petrochemist

    Petrochemist Mu-43 Top Veteran

    652
    Mar 21, 2013
    N Essex, UK
    Mike
    Last edited: May 11, 2015