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Fisheye to Rectilinear using Lumix G 8/3.5

Discussion in 'Creative Corner' started by akulya, Sep 22, 2010.

  1. akulya

    akulya Mu-43 Veteran

    249
    Jun 21, 2010
    Hello,

    Firstly, please give credit to our fellow forum member Miles for taking and sharing the first pictures using this lens on this site (here)

    I have used photoshop cs3 v.10 for windows, and the excellent (and free!) Panorama Tools plugin, although, I am by no means an expert user of either.

    This is a bit of a rough and ready, using a 200K Jpeg as a starting point, but I think it shows a little promise - showcasing the potential to use the fisheye as a UWA prime.

    5014191529_5fcdd1d681_z.jpg
    Subscribe to see EXIF info for this image (if available)


    I have cropped fairly hard, and without really knowing subject distance I cannot make a good guess at what the equivalent focal length might be after correction.

    With a raw file, and a more attenuated process (which will come in time) I would expect at the very least a mediocre improvement in FOV. (i.e something like 20mm FF equiv.)

    If Miles would like to upload something RAW for the community to experiment with; I am sure there would be some smiling faces
     
    • Like Like x 2
  2. Narnian

    Narnian Nobody in particular ...

    Aug 6, 2010
    Richmond, VA
    Richard Elliott
    Thanks! This definitely shows how a limited use lens can be brought into the general use fold. I look forward to the experiments.
     
  3. Gwendal

    Gwendal Mu-43 Veteran

    300
    Jun 6, 2010
    Thanks Akulya ! Very interesting - this would confirm that indeed the fisheye really is a specialty item...
     
  4. akulya

    akulya Mu-43 Veteran

    249
    Jun 21, 2010
    Oh it's a speciality lens yes,

    My thinking was - I will only rarely use a UWA lens, and equally only rarely use a fisheye; but want a high quality lens that has a ~16mm FF FOV, (specifically, one wider than the 9-18 m.zuiko) on those rare occasions I do; will this fisheye fit the bill?

    I know the 7-14 is the natural lens of choice, but it is frankly out of my budget, and although I'm not really into miniturisation for the sake of it, the 8mm is lots smaller and more affordable.

    Lenses at this FL will always be speciality, but the idea of getting one UWA lens for both rectilinear and fisheye uses appeals to me - IF the FOV is still wide enough after distortion correction; and this is still uncertain.
     
  5. Gwendal

    Gwendal Mu-43 Veteran

    300
    Jun 6, 2010
    The 7-14 seems to be around €1000 vs this fisheye €800 - at this price level, isn't it more interesting to go the extra mile ? (interestingly, the page I consulted mentions that the 7-14 is the ideal lens for "taking pictures of your friends" - wonder what they had in mind). And indeed, there is the matter of the actual FOV after necessary corrections, as you mention... even if indeed the size of the fisheye is quite reduced. Anyway, both out of my sights... at least for now ;-)
     
  6. Miles

    Miles Mu-43 Rookie

    22
    Jun 1, 2010
    Luxembourg
    Thanks !

    Thank you akulya for this, I'll post a Raw file on the Image Threat ...

    Miles
     
  7. akulya

    akulya Mu-43 Veteran

    249
    Jun 21, 2010
    Nice one Miles,

    I'm still very much playing with settings until something nice happens but I have tried a couple more using your raw as an original. Sadly it seems that photoshop doesn't like intensive floating point editing with 16bit tiffs (who knew?), so these are max res jpegs from 8bitters.

    Firstly - your original shot
    5016723659_2ec6abcea9_z.jpg
    Subscribe to see EXIF info for this image (if available)


    I straightened it according to the vertical crease in the brickwork, cropped it lightly at the edges, and then ran it through a panotools conversion with the HFOV set at 150° (arrived at via trial and error).

    This gives you an image that is distortion corrected, but border distorted...

    5016751507_e3e2b730cb_z.jpg
    Subscribe to see EXIF info for this image (if available)

    [edit] this red square image was knocked up afterwards, just to illustrate the distortion, and was not used to create the pics below [/edit]

    A constrained 4/3 crop of the centre gives you
    5016723677_17c2e91c92_z.jpg
    Subscribe to see EXIF info for this image (if available)


    An unconstrained "by eye" crop of as much as looks alright (v.subjective obviously) would give something like
    5016723667_4a3415bd64_z.jpg
    Subscribe to see EXIF info for this image (if available)


    I have my working tiffs zipped here if anyone is interested (they're the same as the above jpegs, but bigger)

    I hope people are finding these experiments amusing!
     
    • Like Like x 2
  8. PeterB666

    PeterB666 Mu-43 Top Veteran

    780
    Jan 14, 2010
    Tura Beach, Australia
    Peter
    Very interesting. Certainly a lot of the shot is discarded.

    I would like to see the original of the first image too if you can post it.
     
  9. akulya

    akulya Mu-43 Veteran

    249
    Jun 21, 2010
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