Olympus Pen-F lenses angle of view (equivalent focal length)?

Discussion in 'Adapted Lenses' started by Klorenzo, Apr 13, 2015.

  1. Klorenzo

    Klorenzo Mu-43 All-Pro

    Mar 10, 2014
    Lorenzo
    I was wondering what is the angle of view or the equivalent focal length of an half-frame Pen F lens when adapted on a m43 camera.

    This page on wikipedia:

    http://en.wikipedia.org/wiki/Olympus_Pen_F

    has a 35mm equivalent column that is not twice the focal length.

    The "half-frame" was 24x18 while the m43 is 18x13.5.

    So a 100mm will behave as a 140? Or a 200? Or a 280? Or something else completely? :)

    I would expect a "conversion number" smaller than 2.
     
  2. Turbofrog

    Turbofrog Mu-43 Hall of Famer

    Mar 21, 2014
    The only number you ever need to concern yourself with - ever - when thinking about angle of view, is the real focal length, and the crop factor. The original format, whatever it may have been, is totally irrelevant, except in trying to figure out what kind of image circle it can cover.

    A 20mm Pen F lens (or native Panasonic lens, or 35mm SLR lens, or a 6x7 medium format lens) mounted on an M4/3 camera will have a 40mm (35mm equivalent) angle of view, or a 48.5 degree horizontal AoV if that's easier for you.
     
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  3. dwig

    dwig Mu-43 Top Veteran

    624
    Jun 26, 2010
    Key West FL
    Not quite correct. The original format may not, in itself, be a factor, but the "crop factor" refers to two formats, the original and the new format. m43 has a 2x crop factor relative to 35mmFF. m43's crop factor relative to other formats, such as 35mmSF (aka Half Frame), is 1.3x.

    A 100mm lens, regardless of what its original intended format, will perform the same as any other 100mm lens in terms of field of view, provided it can illuminate the whole frame.
     
  4. Klorenzo

    Klorenzo Mu-43 All-Pro

    Mar 10, 2014
    Lorenzo
    So a 100mm is going to give me the same framing as a native 130mm when adapted?
     
  5. MarkRyan

    MarkRyan Instagram: @MRSallee

    772
    May 3, 2013
    California
    No.

    A 100mm Pen-F lens will give you the same FOV as a 100mm Micro 4/3 lens, assuming both lenses are mounted to the same sensor.
     
  6. Turbofrog

    Turbofrog Mu-43 Hall of Famer

    Mar 21, 2014
    See, this is exactly the kind of confusion that I wanted to avoid.

    How are you used to thinking about focal lengths? Did you use a lot of 35mm film before taking up digital? If not, and M4/3 is your only system, then that makes your life easier. In that case, 7mm-11mm is ultrawide, 12-14mm is a wide angle, 17-25mm is a "normal," around 45mm is a short telephoto/portrait, and 100+ mm is a telephoto.

    A 100mm lens is a 100mm lens is a 100mm lens. Always. It doesn't matter one single bit where that lens comes from. The angle of view that results from that lens will change depending on the sensor you put it in front of (that is the definition of a crop factor, and is really only applied conventionally with respect to 35mm film - larger formats are usually denoted by decimal crops. like 0.61 for medium format), but all lenses of the same focal length are the same when placed in front of the same sensor.

    In other words, don't worry that it's a Pen F lens. Just think of it as a 100mm lens.
     
  7. Klorenzo

    Klorenzo Mu-43 All-Pro

    Mar 10, 2014
    Lorenzo
    I'm used, as many, to use the 35mm as a reference. Before m43 I did shot 35mm film and other formats digital sensors.

    The "35mm equiv." column on wikipedia has got me confused. And thinking about the "crop factor" from half-frame to m43 made things worst.

    So the answer is quite simple: 200mm (equiv)

    Thanks everybody
     
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